Apple has been granted yet another patent (number 10,591,707, dubbed “optical system for head-mounted display) for the rumored “Apple Glasses.”
Such a device will arrive this year, next year, or 2021, depending on which rumor you believe. It 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.”
Head-mounted displays such as virtual reality glasses use lenses to display images for a user. A microdisplay may create images for each of a user’s eyes. A lens may be placed between each of the user’s eyes and a portion of the microdisplay so that the user may view virtual reality content.
Apple says that, if care isn’t taken, a head-mounted display may be cumbersome and tiring to wear. After all, 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 doesn’t want this to be the case if/when the Apple Glasses arrive.
Here’s the summary of the patent data: “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.”