How Disney's Compact AR Display Uses Special Mirrors

Disney's patent describes a compact augmented reality display that uses a clever arrangement of three special wavelength-splitting mirrors to efficiently show digital images layered over the real world.

What it covers

This patent describes an augmented reality (AR) display device designed to show digital images layered onto a user's view of the real world. It achieves this with a specific optical arrangement of three mirror elements. First, a 'dichroic beam splitter' (Claim 1) reflects some light from a display. This reflected light then hits a second mirror, which also has a 'dichroic surface' (Claim 1) designed to reflect red, green, and blue light. Finally, a third mirror reflects this light again, sending it *through* the first mirror element and into the user's 'field of view' (Claim 1). The third mirror is also a 'see-through mirror' (Claim 9), allowing background light from the real world to pass through, combining it with the digital image. For example, a user could wear this device and see digital characters appear to stand on a real-world table.

What it doesn't cover

• —Does not cover AR displays that use only conventional mirrors, rather than dichroic (wavelength-splitting) mirrors, for the first and second mirror elements.
• —Does not cover AR displays where the display light is not reflected sequentially by a first, then a second, then a third mirror element.
• —Does not cover AR displays where the final reflected display light does not pass *through the first mirror element* to the user's field of view.
• —Does not cover virtual reality (VR) displays that completely block the user's view of the real world, as the third mirror element is 'see-through'.
• —Does not cover AR displays that do not specifically reflect red, green, and blue wavelengths using the second dichroic surface.

The clever bit

The novelty lies in the specific, folded optical path using multiple dichroic mirrors. By reflecting and transmitting light based on wavelength and angle, the design efficiently combines digital images with the real world while keeping the overall device compact and maximizing light reaching the user.

Why it matters

This patent addresses the challenge of making AR displays smaller and more efficient, which is crucial for widespread adoption beyond industrial uses. Disney, as the assignee, has a strong interest in immersive entertainment experiences, from theme parks to consumer products. A compact AR display could enable new forms of interactive storytelling and entertainment, seamlessly blending digital content with physical environments.

Real-world examples

• 1.Microsoft HoloLens
• 2.Magic Leap One
• 3.Google Glass (early AR concepts)
• 4.Future AR glasses for entertainment and theme parks