Apple Patent reveals future Glasses with a Pupil Expansion feature that increases the field of view of a Projected Image

Apple Patent reveals future Glasses with a Pupil Expansion feature that increases the field of view of a Projected Image

 

Today the US Patent & Trademark Office published a patent application from Apple that relates to future glasses and/or an HMD. More specifically, the patent covers a pupil expansion feature that is designed to increase the field of view of a projected image onto the optical lens that provides a quality image for AR applications.

 

Patent: Pupil Expansion

 The first of Apple's series of eyewear patents is titled "Pupil Expansion." It generally relates to optical reflective devices, and more specifically to expanding light beams within optical reflective devices.

 Apple notes in their patent filing that one or more holographic optical elements may be used in a waveguide of optical head-mounted display (HMD) device. An HMD device is a wearable device that has the capability of reflecting projected images and may facilitate a user to experience augmented reality.

Head-mounted displays typically involve near-eye optics that project virtual images. In the past, technical limitations of HMDs have resulted in experience impediments including reduced image quality and increased weight and size.

 Past implementations have included conventional optics to reflect, refract or diffract light, however, the designs tend to be bulky. Additionally, conventional mirrors and grating structures have inherent limitations. For example, a conventional mirror may have a reflective axis that is necessarily coincident with surface normal, imposing a suboptimal mirror orientation, or hindered reflective output at the mirror.

Apple's invention generally relates to one or more improved methods, systems, or devices for expanding light beams from an entrance pupil to an exit pupil (i.e., pupil expansion). The methods, systems, or devices may employ one or more pupil expanders or pupil expansion techniques in an optical device or system to enable an increased field of view (FOV) of a projected image.