Solid virtual objects in all light environments
For AR glasses to be worn comfortably all day – a requirement for mainstream adoption – they need to look and feel like normal glasses. They also need to maintain the contrast and visibility of virtual images as users move between indoor and outdoor environments.
Outdoor luminance of real-world objects on a sunny day is 100 times or more higher than indoor objects, making virtual projected objects appear washed out. Ambient dimming can be integrated into the AR glasses lenses to control the amount of real-world light that enters the eye – it’s a feature that’s set to become standard for see-through AR devices.
FlexEnable’s lightweight liquid crystal (LC) dimming cells on plastic switch at video rate and can provide dimming capabilities for AR devices from global down to pixel-level (local dimming) when integrated with our OTFT technology. This enables virtual objects to be clearly visible and appear solid even as external lighting conditions change. Our dimmers can produce black – which a light engine can’t do – and they automatically go to the most transparent state if battery runs out, making AR glasses fail-safe.
Continuously tunable, and with a dynamic range that can be specified by design, the ambient dimming liquid crystal cells are around 100 microns thick, adding almost no weight and volume to devices. The final module can be biaxially formed to follow the shape of visors, fixed optics and other surfaces of complex 3D curvature.
Visual representation of a virtual bird’s visibility through AR glasses under four conditions: no dimmer, global dimmer, segmented dimmer, and pixelated dimmer. Pixelated dimming is essential for clear virtual objects in bright light. FlexEnable is the only company equipped with the technology and IP to manufacture pixelated dimmers on plastic that can also be biaxially thermoformed. (Images are for illustrative purposes only.)
Colour-changing dimmers
Whereas colour-neutral dimmers enhance the contrast of the virtual image for the primary user, colour-changing dimmers have the potential to provide fashion-related benefits, improve colour vision for people with colour-blindness, or simply increase contrast and visibility in changing outdoor light.
FlexEnable uses a Guest-Host Liquid Crystal (GHLC) approach for its colour-changing dimmers. This allows us to create any hue through subtractive colour mixing: from red to yellow to blue, to orange or green or purple. Stacking GHLC allows multi-coloured switching from a single module. We can also vary the depth or intensity of the colour produced by tuning the cell gap and the dye concentration.
