Recently, a new Microsoft patent titled ‘Wearable display device calibration’ was published by USPTO. This patent is trying proposing a method to calibrate a wearable display device.
A challenge to the implementation of wearable display devices, such as a head-mounted display (HMD), for augmented reality is maintaining the alignment of the two, independent left display lens system and right display lens system of a wearable display device. For binocular viewing systems, such as a wearable display device (e.g., glasses or a head-mounted display), the left and right display lens systems generate independent images of the same view. If the left and right display lens systems are not properly aligned so that the left and right images are projected directly one over the other, then the user’s view will appear blurry. This is particularly noticeable for a vertical misalignment of the images, whereas a person’s eyes can adjust to correct for a minor horizontal misalignment of the images. A conventional approach is to utilize a bulky and cumbersome opto-mechanical alignment system.
Abstract of this patent:
In embodiments of wearable display device calibration, a first display lens system forms an image of an environment viewed through the first display lens system. A second display lens system also forms the image of the environment viewed through the second display lens system. The first display lens system emits a first reference beam and the second display lens system emits a second reference beam. The first display lens system then captures a reflection image of the first and second reference beams. The second display lens system also captures a reflection image of the first and second reference beams. An imaging application is implemented to compare the reflection images to determine a misalignment between the first and second display lens systems, and then apply an alignment adjustment to align the image of the environment formed by each of the first and second display lens systems.