Apple has filed for a patent (number 20210132349) for an “optical system for head-mounted display.” It involves the “Apple Glasses,” the rumored augmented reality/virtual reality/mixed reality head-mounted display (HMD).
The goal is to make such a device more comfortable to wear. In the patent filing, Apple notes that a head-mounted display may be cumbersome and tiring to wear. Optical systems for head-mounted displays may use arrangements of lenses that are bulky and heavy. Extended use of a head-mounted display with this type of optical system may be uncomfortable.
Apple says that it “would therefore be desirable to be able to provide improved head-mounted.” How? By making the lens thinner and lighter.
Here’s the summary of the patent filing: “A head-mounted display may include a display system and an optical system in a housing. The display system may have a pixel array that produces light associated with images. The display system may also have a linear polarizer through which light from the pixel array passes and a quarter wave plate through which the light passes after passing through the quarter wave plate. The optical system may be a catadioptric optical system having one or more lens elements.
“The lens elements may include a plano-convex lens and a plano-concave lens. A partially reflective mirror may be formed on a convex surface of the plano-convex lens. A reflective polarizer may be formed on the planar surface of the plano-convex lens or the concave surface of the plano-concave lens. An additional quarter wave plate may be located between the reflective polarizer and the partially reflective mirror.”
When it comes to Apple Glasses, such a device will arrive this year or 2022, depending on which rumor you believe. The Sellers Research Group (that’s me) thinks Apple will at least preview it before the end of the year.
It will be a head-mounted display. Or may have a design like “normal” glasses. Or it may be eventually be available in both. The Apple Glasses may or may not have to be tethered to an iPhone to work. Other rumors say that Apple Glasses could have a custom-build Apple chip and a dedicated operating system dubbed “rOS” for “reality operating system.”