In March 2012 we posted a report titled "Microsoft Invents Projector Eyewear for Xbox & Beyond," that first introduced us to Microsoft's work on projector eyewear for both casual and gaming wearable computing. For the technically minded, two new Microsoft patent applications have come to light that delve into some of the technical aspects of their wide field-of-view virtual image projector. Some of the applications for this invention were first discussed in our special report posted in November in context with viewing live sporting events.
In Microsoft's latest projector eyewear patent we see FIG. 1 shown below presenting an illustration of an example environment in which a wide field-of-view virtual image projector could be implemented. The environment could be implemented in a head-mounted display device such as a pair of eyeglasses 104 or sunglasses 106.
According to Microsoft's filing, a virtual image projector includes a spatial light modulator configured to inject light rays into an input wedge shown below in patent figure 7.
The input wedge acts to output the light rays with an increased fan-out angle into an output light guide positioned proximate the input wedge. The spatial light modulator is controlled to inject light rays into the input wedge effective to diffract the light rays out of the output light guide to generate a virtual image.
In some embodiments, the virtual image projector may be coupled to a pair of eyeglasses to generate the virtual image in front of a lens of the eyeglasses so that a wearer of the eyeglasses, looking through the lens of the eyeglasses, sees the virtual image.
In the big picture, Microsoft states that their invention could apply to other kinds of devices such as a form of flat panel display, television, television client device (e.g., television set-top box, digital video recorder (DVR), etc.), consumer device, computer device, server device, portable computer device, user device, communication device, video processing and/or rendering device, appliance device, gaming device, electronic device, and/or as another type of device.
To review Microsoft's invention, see patent application 20130021392 which was originally filed in Q3 2011.
Total Field of View Classification for Head Mounted Display
Another Microsoft Head Mounted Display (HMD) centric patent application (20120327116) was published by the US Patent Office in December. The patent filing was filed under the title "Total Field of View Classification for Head-Mounted Display." In that particular filing, Microsoft discussed the use of on-board sensors that could track the position and rotation of the HMD wearer's head relative to the HMD wearer's body and surrounding environment so that augmented information could be positioned properly in the HMD wearer's total field of view (TFOV) which could be classified into regions. Virtual images would then be located in the classified TFOV regions to locate the virtual images relative to the HMD wearer's body and surrounding environment.
The HMD may also include one or more eye-tracking sensors, which typically track the movement of the pupil or other portions of the eye or the area around the eye to determine the direction of a user's gaze. This may be accomplished, for example, using IR or RGB cameras aimed at the HMD wearer's eyes. Microphones may be provided to collect audio information, including the HMD wearer's voice and surrounding environmental audio. Biometric sensors may be used to collect biometric information for the HMD wearer.
By way of example, Microsoft's patent FIGS. 3A and 3B shown below illustrate a profile view and front view, respectively, of a TFOV 302 for an HMD wearer 304. As shown in FIGS. 3A and 3B, the TFOV has been classified into a primary region 306, a secondary region 308, and a tertiary region 310.
TFOV regions may dynamically change by automatically adjusting the size (i.e., expanding or shrinking) of regions, shifting regions within the TFOV, or completely re-classifying new regions for the TFOV. The regions may automatically change based on rules triggered by events, environmental conditions, body placement and movement, and additional sensor information.
For instance, if the HMD wearer is sitting, the primary region may be relatively small since the HMD wearer is stationary and it's safer to occlude more of the HMD wearer's FOV. However, if the HMD wearer stands and begins to walk, the primary region may expand such that less of the HMD wearer's FOV is occluded with virtual images. If the HMD wearer begins running or begins to drive a car, the primary region may expand even further.
As an example of re-classifying regions, suppose the HMD wearer's eyes are gazing and hands are moving in a secondary region of the TFOV. This may be indicative that the HMD wearer is performing some task in that space. As a result of these inputs, the TFOV may be re-classified such that region is now the primary region. Other environmental conditions may also affect the classification of regions. For instance, biometric inputs may indicate that the HMD wearer is nervous or frightened. In response, the primary region may expand.
Examples of fixed regions versus dynamic regions are provided in Patent FIGS. 4 and 5 above. Initially, FIG. 4 illustrates an example of fixed regions. As shown in FIG. 4, as the HMD wearer moves his/her head looking up and down, the regions remain fixed. In contrast, FIG. 5 illustrates an example of dynamic regions. As shown in FIG. 5, as the HMD wearer moves his/her head up and down, the regions move with the HMD wearer's head movements.
Microsoft's virtual imaging system includes a head position component that is operable to receive sensor data from the on-board sensors and determine the HMD wearer's head position and rotation relative to HMD wearer's surrounding environment and the HMD wearer's body. By way of example only and not limitation, the head position component may employ techniques such as simultaneous location and mapping (SLAM) using, for instance, camera data and/or depth sensor data to provide a real-time position of the HMD wearer's head relative to a mapped surrounding environment.
An IMU (Inertial measurement unit) may also provide relative rotation and position information even when the camera or depth sensors are unavailable. Regions of the HMD wearer's body (e.g., hand, arm, torso, legs, feet, etc.) may also be identified using sensor data. For instance, camera data and/or depth sensor data may be obtained when the HMD wearer is looking at him or herself. As such, the HMD wearer's head position and rotation relative to the HMD wearer's body may be inferred to a useful degree of accuracy. This may include information such as whether the HMD wearer is standing, sitting, looking straight ahead relative to torso, to name a few.
With Google focused on delivering their Project Glass eyewear to the market over the next 18 months, the pressure is on both Microsoft and Apple to get into this future segment in a timely way so as to not give Google an insurmountable lead in the area of wearable computers. Only time will tell who will not only be first to market but who will have a better product in terms of usability.
To date, Microsoft's has more published patents in the field of computer eyewear than does Apple.
The Patent Bolt blog presents a detailed summary of patent applications with associated graphics for journalistic news purposes as each such patent application is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent application should be read in its entirety for full and accurate details. Revelations found in patent applications shouldn't be interpreted as rumor or fast-tracked according to rumor timetables. About Comments: Patent Bolt reserves the right to post, dismiss or edit comments.
