Apple Invents a Lens Position Sensing System for a Headset that can adjust lens accuracy for different Face Profiles
Earlier this morning Patently Apple covered Apple's first HMD invention patent in a report titled "Headset with a transitioning face-side cover that darkens when viewing VR content & transparent for AR content." In Apple's second HMD invention published today, we learn about a lens positioning system designed to accommodate different size faces in general and in one's family so that Dad's lens positioning will also be able to change to fit his teenage kids' faces of different ages.
Most HMDs are designed with a one size fits all position whereas Apple is going the extra mile to ensure that one HMD in the family will be able to fit everyone's vision while ensuring that there's a comfortable fit when the HMD is sitting on their nose.
Apple notes that head-mounted devices are provided with head-mounted structures that allow the devices to be worn on users' heads. The head-mounted devices may include optical systems with lenses. The lenses allow displays in the devices to present visual content to users.
However, users have faces of different shapes and sizes. This can pose challenges when a head-mounted device is to be used by multiple users. If care isn't taken, a head-mounted device may not fit well for certain users.
Apple's invention covers a solution for that problem with new lens positioners. Apple notes that a head-mounted device may have lenses in lens modules. A left positioner may be used to position a left lens module. A right positioner may be used to position a right lens module. The left and right lens modules may have respective left and right lenses and respective left and right portions of a display.
To accommodate users with different interpupillary distances, the left and right lens modules may be moved towards or away from each other. To avoid excessive pressure on a user's nose, sensing circuitry such as proximity sensing circuitry may be used to detect relative positions between the left and right lens modules and facing surfaces of the user's nose. Control circuitry may adjust the lens modules using the interpupillary distance information for the user and using information from the sensing circuitry to prevent excessive pressure from the lens modules on the user's nose.
A user may supply the interpupillary distance of the user to the head-mounted device, an image sensor or other device may be used in measuring the interpupillary distance to provide to the head-mounted device, and/or gaze tracking sensors in the head-mounted device may measure the interpupillary distance of the user while the head-mounted device is being worn on the head of the user.
In some configurations, a proximity sensor such as a capacitive proximity sensor may have electrodes on flexible printed circuits that are coupled to the gaze tracking sensors. Other sensing arrangements may be used to measure lens module positions relative to the user's nose, if desired.
As shown in FIG. 3 below, the inner edges of left and right lens modules #70 may be adjacent to corresponding side surfaces #42 of the user's nose #40 when wearing the HMD.
To ensure that the display is viewable by the user when the user's eyes are located in eye boxes, control circuitry attempts to align lens centers LC with the centers PC of the user's eyes.
At the same time, the control circuitry uses sensor circuitry such as proximity sensors to detect the position of inner edges #70E of lens modules #70 relative nose side surfaces #42 to ensure that lens modules do not press excessively on the user's nose and cause discomfort.
In scenarios in which the user's nose is small, there may be ample room available to align Lens Centers (LC) with eye centers PC. In scenarios in which the user's nose is larger, control circuitry may position modules as shown in FIG. 3, where lens-to-lens spacing LD is larger than would be desired for perfect alignment of lens centers LC with eye centers PC.
The user of this wider lens-to-lens spacing helps ensure that edges #70E of lens modules #70 will not exert more inward force on surfaces of nose 40 than would be comfortable to a user, while still allowing satisfactory viewing of content on the display through the lenses.
Lens module surfaces #70E may be placed at a non-zero distance (gap) from corresponding adjacent surfaces #42 as shown in FIG. 3 or may rest gently against nose surfaces. A user may select which of these options is most comfortable to the user and/or a default setting may be supplied to control the circuitry.
Apple's patent FIG. 5 above is a circuit diagram of an illustrative control circuit for controlling a positioner motor while monitoring for feedback from the motor.
Apple's patent application 20200064635 that was published today by the U.S. Patent Office was filed back in Q1 2019. Considering that this is a patent application, the timing of such a product to market is unknown at this time.
Some of the inventors listed on the patent include: Jeremy Franklin (Product Design Manager); Tao Jia (Machine Learning SW Engineer); and Stephen Dey (Product Design Manager).