Lectures

2024
2024_tst_display_week.png

Impact of Calibration Sources on Accuracy of Chromaticity Measurements

Date: 2024/05/16, 09:40 AM (GMT-7)

Dr. Tobias Steinel

Session 58.3

Location: Display Week, San José, CA/ USA


When narrow bandwidth emission sources such as µLEDs are used to create full color displays, large measurement errors can occur with colorimeters calibrated against standard light sources. Experiments confirm that different calibrations of an imaging light measurement device provide different levels of color accuracy depending on the similarity of calibration source to the DUTs spectral distribution.

More
2024_FDE_DW_Short_Course.png

Fundamentals of Display Metrology

Date: 2024/05/12, 10:00 AM (GMT-7)

Dr. Ferdinand Deger

SID/ICDM 2024 Display Metrology Training Course in cooperation with Radiant Vision Systems

Location: Display Week, San José/CA, USA


The significance of displays is evident in their ubiquity across technologies and industries and their footprint, growing to encompass entire device surfaces and fields of view. Display metrology provides an objective understanding of a display’s quality and performance through data, supplying tools for display innovation and evaluation to safeguard manufacturing investment.

More
2024_asa_spie_eu.png

Characterization of Semiconductor Lasers at SWIR Wavelength

Date: 2024/04/11, 01:40 PM (GMT+1)

Dr. Amir Sharghi

Paper 13002-29

Location: Strasbourg, France


Semiconductor lasers have become the light source of choice in many applications. IR VCSELs are widely used for sensing purposes in consumer electronics. On the other hand, longer wavelength i.e. SWIR are appearing and expected to rise.

More
2024_tst_edc.png

Live Colorimeter Calibration Adapts to Spectral Variations of Measurement Object

Date: 2024/04/10, 01:20 PM (GMT+1)

Dr. Tobias Steinel

Location: electronic displays conference, Nuremberg/ Germany


In principle, all colorimeters need color calibration, because the color filters that are used to mimic the eye’s sensitivity to visible light will never perfectly match the theoretical CIE 1931 functions.

More
2024_sre_edc.png

Matching One-Shot Imaging Light Measurement Devices with Goniophotometer Measurements in VR Applications

Date: 2024/04/10 – 2024/04/11

Dr. Sascha Reinhardt

Location: electronic displays conference, Nuremberg/ Germany


A goniophotometer frequently acts as a gold standard in measuring XR components or headsets. The benefit of precise spectrometer results are normally correlated with longer measurement times.

More
2024_ASA_PW.png

One-shot single-emitter-resolved polarization and LIV+λ characterization of a VCSEL array at tempered conditions

Date: 2024/01/31, 11:35 AM (GMT-8)

Dr. Amir Sharghi

Session 12904-11

Location: SPIE Photonics West, San Francisco/CA, USA


With the existing solutions, for VCSEL arrays it is hardly possible and timely expensive to perform LIV+λ measurements, since there are a few up to some hundreds of single emitters within the array. Furthermore, polarized VCSEL arrays are unique and have potential applications, which then require not only the LIV+λ analysis but also a polarization measurement of each emitter.

More
2024_ASA_SPIE_ARVRMR.png

Safety Assessment of Virtual Reality eye tracking modules

Date: 2024/01/29, 03:30 PM (GMT-8)

Dr. Amir Sharghi

Session 12913-55

Location: SPIE AR|VR|MR, San Francisco/CA, USA


VR devices widely use multiple near-infrared LEDs for eye tracking. However, NIR illumination is potentially harmful to the human eye and skin. The international photobiological safety standard IEC 62471 provides guidelines for evaluating the photobiological hazards of incoherent broadband light sources.

More
2024_TST_SPIE_ARVRMR.png

Light measurement and quality control at different production stages of a virtual reality headset

Date: 2024/01/29, 10:50 AM (GMT-8)

Dr. Tobias Steinel

Session 12913-45

Location: SPIE AR|VR|MR, San Francisco/ CA, USA


The production of a Virtual Reality headset is a complex process with several steps. At each step, various measurements are taken to verify quality or to characterise the component for later use. The visual system is the key component of a VR headset and consists in general of a display and an optical lens, which form the optical module.

More
2023
2023_C-Touch_Tianxing.png

Rapid Testing of µLEDs and µDisplays on Wafer

Date: 2023/10/12, 03:30 PM (GMT+8)

Tianxing Zhu

Location: C-Touch & Displays, Shenzhen, China


The upcoming μLED display technology promises high contrast, fast response time, wide color gamut, low power consumption, and long lifetime. But, the technology is challenging for optical quality control, especially for narrow bandwidth μLEDs.

More
2023_SID_Vehicle_Displays_Kevin.png

Optical characterization of curved displays

Date: 2023/09/27, 02:20 AM (GMT-4)

Kevin Lange

Location: SID Vehicle Displays & Interfaces, Detroit/MI, USA


Among the new display trends of the past few years, so-called curved displays have been particularly successful. Their curvature opens up a multitude of new possibilities in terms of design and application. Whether an instrument panel is perceived as pleasant, is still legible in sunlight or switches fast enough in cold winter temperatures, are parameters for individual assessment. A further quality factor is the stability of the perceived image content. For example, it is perceived as unpleasant when contrast and color change with the direction of viewing.

The 7-axis goniometer (DMS 904) expands the DMS series portfolio of goniometers to include a display measurement system that is specially geared to the above measurement tasks.

More
2023_DSCC_SRE.jpg

Light Measurement of VR devices

Date: 2023/09/13, 02:30 PM (CEST)

Dr. Sascha Reinhardt

Location: DSCC AR/VR Forum - online


Light measuring devices (LMD) are essential tools for developing novel display technologies as well as for quality assurance in display mass production. More complex displays, e.g. Near Eye Displays (NED), might require various LMDs in different development and production phases.

More
2023_Trendforce_MicroLED_Forum_Jack_Hwang.png

Rapid Testing of µLEDs and Microdisplays on Wafer

Date: 2023/09/05, 11:10 AM (GMT+8)

Jack Hwang

Location: Micro LEDForum 2023, Taipei/ Taiwan


Two-dimensional high-speed measurement of on-wafer. PhotoLuminescence and ElectroLuminescence and their single-pixel evaluation.

More
2023_tst_dff.png

Massive Parallelization of Optical Quality Control of μLED Displays and Wafers

Date: 2023/07/06, 02:50 PM (GMT+2)

Dr. Tobias Steinel

Location: 2nd Focus Meeting of the DFF, Ittervoort/ Netherlands


More
2023_tst_epic-isa.png

High-throughput MicroLED Wafer Testing

Date: 2023/07/04, 11:30 AM (GMT+2)

Dr. Tobias Steinel

Location: online


More
2023_asa_spie_om.png

Two-dimensional LIV and beam quality characterization of individual emitters in a VCSEL array

Date: 2023/06/28, 08:40 AM (GMT+2)

Dr. Amir Sharghi

Location: SPIE Digital Optical Technologies, Munich/ Germany


LIV curves are fundamental measurement of laser diodes to determine electrical and optical operating characteristics. LIV curves consist of L-I curves (optical intensity against current) and V-I curves (voltage against current). LIV curves determine power conversion efficiency, threshold current, slope efficiency, kinks, rollover point and more. LIV curves are widely used at various stages since it is critical to identify failed DUTs early in the manufacturing process.

More
2023_tst_icdt.png

Rapid Testing of μLEDs and Microdisplays on Wafer

Date: 2023/04/02, 05:10 PM (GMT+8)

Dr. Tobias Steinel

Location: ICDT / online


The upcoming μLED display technology promises high contrast, fast response time, wide color gamut, low power consumption, and long lifetime. But, the technology is challenging for optical quality control, especially for narrow bandwidth μLEDs.

More
2023_ali_edc.png

Characterization and Prevention of Global and Rolling Shutter Artifacts in Display Metrology

Date: 2023/03/15, 04:10 PM (GMT+1)

Andreas Liebel

Location: electronic displays conference, Nuremberg/Germany


State of the art displays do have the ability to modulate refresh rate and duty cycle in order to save energy and to adapt to the display content. These features pose new challenges to display metrology equipment and may produce image artefacts. Here, we discuss the characterization and prevention of image artifacts due to the shutter type of the camera used for high accuracy display testing.

More
2022_tst_pw.jpg

Validating distortion measurements of wide-field-of-view near-eye displays

Date: 2023/01/30 – 2023/02/01, 06:00 PM (GMT -8)

Dr. Tobias Steinel

Location: SPIE AR|VR|MR , San Francisco/CA, USA


Near-Eye Displays covering a large field of view require complex optical imaging systems. While the optical system is designed to minimize distortion, residual distortion, material or production flaws lead to significant distortion. Imaging light measurement devices (ILMD) are used to detect distortion for product quality assurance. However, imaging measurement systems, especially with wide-angle lenses, may also add distortion to the measurement. Therefore, the calibration of ILMDs is crucial for the measurement of AR/VR device distortion. Here, we quantify and validate the accuracy of methods of distortion correction for an imaging light measurement device with a field of view of 120°.

Daily Poster Session from 6.00 pm - 7.30 pm

More
2022
2022_tst_cioe.png

Comprehensive Extended Reality Test and Audit Solutions

Date: 2022/11/17, 04:00 PM (GMT +8)

Dr. Tobias Steinel

Location: CIOE (online)


Visible and infrared light measurement devices (LMDs) are essential tools for developing novel extended reality display and sensing technologies as well as for quality assurance in the display and headset mass production. Extended reality devices come with a multitude of test requirements and the need to measure the same way as the human eye sees, and also might require different LMDs in the development and production phases.

More
2022_CDI_Epic_NPI.png

New High resolution Infrared Array spectrometer CAS 140D IR

Date: 2022/11/08, 04:00 PM (CET)

Claudia Dippold

Location: online


In this EPIC Members New Product Release, our Product Manager Claudia Dippold will introduce Instrument Systems' latest CAS 140D IR spectroradiometer for measurements in the infrared range. It features the proven high measurement accuracy and reliability of the CAS140D series, recognized all over the world as a reference for wavelengths from 780–1700 nm. Compared to its predecessor model, the new CAS 140D IR offers significantly improved performance in signal sensitivity, stray light suppression and electronics.

More
2022_SID_Vehicle_Displays_1.png

Fast 2D Display Testing with Spectrally Corrected Colorimeters

Date: 2022/09/27, 11:40 AM (EST)

Justin Blanke

Location: Detroit/MI, USA


Displays are becoming more and more prevalent in the automotive cabin and must serve a variety of functions flawlessly in a challenging environment. Specialized analysis to measure effects such as Black Mura must be conducted according to established standards; this enables meaningful comparison between supplier and manufacturer.

More
2022_SID_Vehicle_Displays_1.png

VCSEL Characterization: LiDAR and Eye-Safety Testing

Date: 2022/09/27, 12:00 PM (EST)

Justin Blanke

Location: Detroit/MI, USA


Vertical-cavity surface-emitting lasers (VCSELs) perfectly fulfill the requirements for present and future 3D sensing applications. However, to operate VCSEL-based devices in public, the manufacturer must assure “eye safe” operation compliant with the IEC 60825-1 standard or national equivalents. As VCSELs exhibit special emission characteristics that differ from other laser sources, the safety assessment is more complex, and a practical guideline does not exist.

More
2022_tst_dscc-arvr.jpg

Comprehensive Extended Reality Test and Audit Solutions for Near-Eye Displays, Headset Infrared Light Sources and Optical Components

Date: 2022/09/20, 09:30 AM (EST)

Dr. Tobias Steinel

Location: online


Visible and infrared light measurement devices (LMDs) are essential tools for developing novel extended reality display and sensing technologies as well as for quality assurance in the display and headset mass production. Extended reality devices come with a multitude of test requirements and the need to measure the same way as the human eye sees, and also might require different LMDs in the development and production phases.

More
2022_ali_icdt.png

Uniformity of OLED Displays at Ultra Low Luminance

Date: 2022/07/15 – 2022/07/18

Andreas Liebel

Location: ICDT/ online


Next generation OLEDs displays have in principle endless contrast ratios due to their emittive nature. However, in practice OLED displays show non-uniformities at very low luminance which have to be measured and corrected in order to maintain constant contrast.

In this presentation, uniformity measurements at very low luminance will be presented and results from displays from a variety of manufacturers will be compared.

More
2022_tst_edc.png

Luminance Dependent Uniformity in OLED Displays

Date: 2022/06/21

Dr. Tobias Steinel

Location: electronic displays conference, Nuremberg


Next generation OLEDs displays have in principle endless contrast ratios due to their emittive nature and their ability to completely turn off pixels. This makes them ideal in applications that require low display luminance like use in dark/nighttime conditions.

More
2022_kiy_epic.png

The importance of polarization characterization and eye safety assessment of VCSELs

Date: 2022/06/12

Dr. Karthik Iyer

Location: EPIC Online Technology Meeting


Novel VCSEL arrays require spatial testing of the whole ensemble as well as of the single emitters in the near-field. Such optical measurements must be calibrated, corrected for polarization dependency and traceable to ensure minimum error budgets for eye safety evaluation.

More
2022_fmu_pw.png

Spatially-resolved polarization characterization of VCSEL arrays

Date: 2022/01/26

Dr. Frank Münchow

Location: San Francisco/CA, USA


Although VCSELs are intrinsically single-longitudinal mode devices, they usually show complex polarization characteristics. Most VCSEL are not designed to emit in a single polarization state, there is no control about the polarization angle. The light emitted by the VCSEL typically show a complicated polarization, even within one emitter and abrupt polarization switching can be observed when temperature or bias current is changed. In this presentation we show a method of measuring spatially resolved polarization characteristics of VCSELs. This is achieved using a combination of polarization filtered microscope optics and a CMOS camera.

More
2022_tst_pw.jpg

Sharpness and Contrast of AR/VR Near-Eye Displays: Goniometric vs. Advanced 2D Imaging Light Measurements of the Modulation Transfer Function (MTF)

Date: 2022/01/22 – 2022/01/24

Dr. Tobias Steinel

Location: San Francisco/CA, USA


Novel display technologies for AR/VR/MR devices require distinct tests to control quality during development and in production. Sharpness and contrast tests are particularly important due to the complex overlay of real and augmented images. Clear and immersive perception of the augmented or virtual reality requires optimal optical differentiation between different display contents. Typically, the modulation transfer function (MTF) acts a measure for sharpness and contrast. For accurate MTF measurement, an imaging test system should be based on a lens system that mimics the human eye system and have a similar-sized entrance pupil in front of the lens.

More
2022_kiy_psc.jpg

One Shot: Polarization Characterization of VCSELs

Date: 2022/01/11 – 2022/01/11

Location: Online


VCSEL-based sensor technology supports innovative applications. As VCSELs have special properties, in contrast to other typical laser sources, their characterization is more complex.

More
2021
2021_chu_idw.jpg

AR/VR Near-Eye Displays: Meeting their Distinctive Challenges in Display Quality Control

Date: 2021/12/02

Dr. Cameron Hughes

Location: IDW'21 Virtual Conference


Near-eye displays (NEDs) exhibit a number of effects including distortion and sharpness distribution due to the optics that generate the virtual image. In his lecture, Dr. Cameron Hughes presents why a spectrally enhanced camera based system such as the LumiTop is ideal for fast and accurate production testing of these displays.

More
KW43_EPIC_Product_launch.jpg

Nearfield VCSEL Testing Camera VTC 4000

Date: 2021/11/01

Dr. Karthik Iyer

Location: Virtual


During the EPIC Members New Product Release, Instrument Systems' Program Manager Dr. Karthik Iyer presented our Nearfield VCSEL Testing Camera – VTC 4000.

More
2021_dko_optics_photonics.jpg

Measurement systems in the UV A/B/C range

Date: 2021/07/31 – 2021/08/04

Dr. Ðenan Konjhodžić

Location: virtual | Optics + Photonics, San Diego/ California, USA


Nowadays, the pandemic situation caused by the COVID-19 virus inspired many companies, research institutes and lighting designers to adopt UV radiation as a new tool in their projects and research. The promising germicidal effect of the UVC radiation also on the Coronavirus raises the question of the reliable measurement of the UV radiation. However, this complex task needs an expertise and appropriate equipment.

More
2021_tst_icdt.jpg

MicroLED Metrology: Challenges and Solutions

Date: 2021/05/31

Dr. Tobias Steinel

Location: ICDT, Online / Beijing Etrong International Exhibition & Convention Center, Conference Hall 1, Meeting Room C


The upcoming μLED display technology promises high contrast, fast response time, wide color gamut, low power consumption, and long lifetime. However, the technology is not only challenging for mass transfer of the µLEDs from wafer to display, but also for massive parallelization of optical quality control at different manufacturing steps.

More
2021_tst_sid.jpg

Color Uniformity of µLED Displays: New Color Calibration Concept for Fast and Accurate Optical Testing

Date: 2021/05/20

Dr. Tobias Steinel

Location: Display Week 2021 Virtual Conference


Superior properties of µLEDs for display applications challenge metrology with, e.g, narrow emission bandwidth and enormous wavelength variability depending on their electronic driving parameters. Therefore, we developed new imaging test solutions to make color uniformity measurements fast and highly accurate even for strongly varying spectral properties of µLEDs.

More
2021_rha_sid.jpg

Short Course S-2: Fundamentals of Display Metrology

Date: 2021/05/19

Dr. Reto Häring in cooperation with Konica Minolta and Radiant Vision Systems

Location: Display Week 2021 Virtual Conference


This short course will provide a fundamental understanding of display metrology and introduce measurement equipment and techniques. It is held in cooperation with Konica Minolta and Radiant Vision Systems.

More
2021_dko_iculta.jpg

Measurement systems and calibrations for UV radiation

Date: 2021/04/19

Dr. Ðenan Konjhodžić

Location: Online


Nowadays, the pandemic situation caused by the COVID-19 virus inspired many companies, research institutes and lighting designers to adopt UV radiation as a new tool in their projects and research. The promising germicidal effect of the UVC radiation also on the Coronavirus raises the question of the reliable measurement of the UV radiation. However, this complex task needs an expertise and appropriate equipment.

More about the abstract
2021_tst_spie.png

Quality control of AR/VR near-eye-displays: Goniometric versus advanced 2D imaging light measurements

Date: 2021/03/27 – 2021/03/29

Dr. Tobias Steinel

Location: SPIE AR/VR/MR, Live on Demand, Conference 11765-36


Novel display technologies for AR/VR/MR devices require advanced imaging systems to control quality during assembly and to calibrate the device. Such calibration yields an optimal match of left and right eye and allows color management for an accurate match of real world and virtual objects. For accurate measurement, such an imaging system should be based on a lens system that mimics the human eye system and have a similar-sized entrance pupil in front of the lens. Traditionally two approaches have been proposed:

Read the abstract
2021_tst_edc.png

Human-Centric Quality Control of AR/VR Near-Eye-Displays and AR-HUDs

Date: 2021/03/04

Dr. Tobias Steinel

Location: electronic displays Conference 2021 digital


Novel display technologies for augmented and virtual reality (AR/VR/MR/XR) devices, like Head-Mounted-Devices and Head-Up-Displays, require advanced imaging systems and calibration to control quality during assembly to accurately match the real world and virtual objects. We demonstrate and compare advantages of goniometric sampling spot measurements and camera based imaging solutions.

More information
2021_kpr_PhotonicsSpectraConference.jpg

Characterization of VCSELs for 3D sensing applications according to the IEC60825-1 Standard

Date: 2021/01/18

Dr. Katharina Predehl

Location: Online Event


VCSELs have special properties in contrast to other typical laser sources. As a result, VCSEL eye safety evaluation is more complex and a couple of additional aspects have to be considered that would not apply for "normal" lasers. Consequently, the validation of a VCSEL's laser class is not trivial, and even more so because an easily understandable guideline for the assessment of VCSEL safety has not yet been published.

More