Patent reveals Apple AR glasses optical waveguide with three image planes near, far and medium

Leifeng.com: After many people's expectations for Magic Leap were dashed, they can only pin their hopes on Apple's AR glasses to be released in 2021. Recently, Patently Apple discovered a new Apple patent in Europe, which is closely related to the legendary Apple glasses. The head-mounted device in the patent not only supports Apple's main AR, but also supports VR and holographic content display. The patent describes Apple's optical waveguide solution in detail. Compared with Magic Leap's two-layer optical waveguide solution, Apple can display three layers of image planes: far, medium and near.

Product Outlook: Apple's head-mounted display device patent may evolve into a variety of products in the future, such as portable consumer electronics (mobile phones, tablet computers, glasses and other wearable devices), head-up displays (aircraft and car cockpits, etc.) and display-based devices (projectors, TVs, etc.). The above devices may include screens and other optical components, and the system will support mixed (MR/VR/AR) reality and other content.

Patent background: Head-mounted displays can be used to display VR and AR content. When displaying AR content, it overlays computer-generated images on real-world objects, while the screen and optical system are used to generate the images and display them to the user.

If the technology isn’t up to scratch, the components that display content on the headset could be unnaturally large and ugly, and the makeshift design might not deliver the optical performance it deserves.

Optical devices such as head mounted displays often require a display system that generates images. An optical system with one or more optical waveguides and an input/output coupler system can also be used to distribute images to the user.

According to Leifeng.com, the display system may have one or more pixel arrays, such as a liquid crystal on silicon (LCOS) pixel array. The image from the display system may be coupled to one or more optical waveguides through a coupler system, and of course it is also possible to couple optical waveguides in multiple image planes using an output coupler system.

Input and output coupler systems may feature single couplers, coupler stacks, and tiled array couplers. These couplers may be thin planar volume holograms or other optical couplers that couple light into or out of the upper and lower surfaces of an extended ribbon waveguide.

Image signals such as wavelength, polarization, time division and angle multiplexing techniques all have different angular orientation ranges, and lens tunability techniques can also be used to display images on multiple image planes to the user.

The picture below is a schematic diagram of the head-mounted display in Apple's patent.

figure 1

The head-mounted display #10 may be equipped with an input-output circuit #52, which allows the head-mounted display to receive data from external devices and allows the user to complete input. The components in the input-output circuit #52 can also enable the head-mounted display to provide output functions to the user and even help them communicate with external electronic devices.

A camera or other device in input-output circuit #52 may be pointed toward the user's eyes and track their eye movements. Sensor #70 may incorporate position and motion sensors (such as a compass, gyroscope, GPS, and accelerometer) to monitor the position, orientation, and motion of the head mounted display #10.

For example, the orientation of a user's head relative to the surrounding environment can be monitored using the sensor #70 and the control circuit #50. The movement of the user's head can also be tracked in real time using the sensor.

The support structure #16 in FIG.2 can be transformed into a pair of glasses with a little configuration. Of course, it can also be made into a helmet, goggles or other forms of head-mounted equipment.

The optical system can be configured to display different images on different image planes #94. This means that objects farther away (such as the top of a mountain in a landscape image) will appear on a farther image plane (such as the far-field image plane #94D), closer objects will appear on a closer image plane (such as the near-field image plane #94N), and other objects may appear on a medium-distance image plane (#94-I). This solution can provide users with realistic 3D image content while reducing user eye fatigue and discomfort.

figure 2

FIG.2 (above) in Apple's patent is a top view of the head-mounted device.

Holographic system: FIG.6 below is a cross-sectional side view of an optical system (with an optical waveguide and adjacent pixel array) equipped with an optical waveguide, a pixel array, and a stack of auxiliary holographic input couplers and holographic output couplers, each of which responds to light with different directions, ranges, and image planes.

image 3

Tunable lens: FIG.13 below is a diagram of an optical system involving a tunable lens, an optical waveguide, and an input-output coupler for presenting an image.

Figure 4

Sensors: Apple pointed out in the patent that their head-mounted devices will be equipped with temperature, touch, capacitance, light, gas, pressure and humidity, magnetism, deformation and force sensors.

Audio components: The audio components must include a microphone for collecting voice commands and other audio inputs, and of course speakers that provide audio output (such as in-ear headphones, bone conduction speakers, etc.).

Haptic feedback: Input-output devices may be equipped with tactile output devices (such as vibration mechanisms), emitting secondary lights or other light sources and output components.

Wireless communications: Device circuitry may support wired and wireless connections to allow the head-mounted display to "communicate" with external devices (such as remote controls, joysticks, portable electronic devices, computers, screens, and other input controllers). This allows signals to flow freely between components in different parts of the head-mounted display.

Apple's patent application was only submitted in the first quarter of this year and was officially approved in Europe on September 13.

Leifeng.com noticed that the title image comes from a helmet display (HMD) patent that Apple applied for in 2013, while today's patent is a utility patent that focuses on the mechanical structure of the device rather than its appearance. In other words, this is not a design patent, so any head-mounted display images in it are used to explain the principles of the product. Of course, fans don't have to worry, with Jony Ive and his design team in charge, Apple will not disappoint in design, whether it is a head-mounted device or glasses.

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