NED Lens Accessory for Measuring the Performance of Wearable AR & VR Displays

The Westboro Photonics XR1 is a periscopic near eye display (NED) lens that has been purpose designed for testing wearable displays that are used in augmented reality (AR) and virtual reality (VR) applications. The periscope design ensures the lens readily fits into the final assemblies of glasses, headsets and helmets. Under different stimuli, human visual accommodation results in varying pupil diameters. Therefore, the entrance pupil aperture is adjustable from 1.5 to 5.0mm. This lens can be fitted to the WP6E, WP6ES and WP512 series of imaging colorimeters or imaging spectral colorimeters.

AR/VR Wearable Near-to-Eye Display Testing

Characterising the visual performance of near-to-eye displays (NEDs) requires a special lens that emulates the optics of the human eye. To do this, Westboro Photonics’ XR1 NED Lens features an entrance pupil at the front of the lens, and its size can be changed from 1.5 mm to 5 mm — simulating typical users’ visual adaptation in bright and dark environments. The XR1 NED lens design, paired with a Westboro Photonics imaging colorimeter, enables outstanding measurement and analysis of AR and VR display systems.

Optimised For Augmented Reality Displays

The XR1 NED lens is specifically designed to provide optimal imaging performance for AR displays with up to 73° diagonal field of view (FOV).

Made to Fit

It is important that the portion of the lens near the NED is narrow and tapered so the entrance pupil (EP) of the lens is positioned at the exit pupil (XP) location of the NED. The XR1 NED lens is designed to fit the confined eye box spaces of the helmet, headset or glasses. Three features of the XR1’s design enable proper alignment:

• The lens barrel is relatively thin at only a 56mm diameter
• The lens barrel is tapered near the entrance pupil
• The lens has a folded and rotatable periscope design

Key Features

• 1.5 – 5.0mm external entrance pupil
• 73° field of view
• Polarisation insensitive
• Low distortion
• 0.3 m – ∞ focus range
• Rotating periscope design
• Slim form factor
• 45° approach angle

High Accuracy Measurements from Integrated Spectroradiometer

The XR1 NED lens is compatible with the WP5 and WP6ES imaging colorimeters, which both feature integrated spectroradiometers for the highest accuracy results possible. The WP5 excels at high-speed production whereas the WP6ES is appropriate for R&D, engineering and lower volume production.

Flexible for Research and Development

Interchangeable external entrance pupils are located at the front of the XR1 lens. Standard diameters include 1.5, 2.0, 3.0, 4.0 and 5.0mm. Custom sizes are also available. The lens can focus from 0.3m to infinity. Automation of the focus is possible via external motors.

Analysis Software

All Westboro Photonics imaging systems include Photometrica software, which has the tools you need to characterise display performance including:

• MTF
• Contrast
• Gamut and white point
• Luminance and colour uniformity
• Distortion

Compatible Colorimeters

The XR1 lens accessory is compatible with the following Westboro Photonics instruments:

• WP690E/ES 9-megapixel imaging colorimeters
• WP6120E/ES 12-megapixel imaging colorimeters
• WP512 imaging spectral colorimeter