Abstract: Provided is an apparatus which includes a near-to-eye display, a microcontroller, a hot shoe interface with an external port configured to communicate with an external mounting device for the near-to-eye-display, a hot shoe interface line between the external port and the microcontroller, and a communication line between the external port and the microcontroller. The communication line is configured to share at least a portion of the hot shoe interface line, and is also configured to transmit and receive external communications through the external port. The microcontroller is configured to activate and inactivate transmission over the communication line in response to predetermined signals received over the communication line within a first predetermined time period of at least one of the near-to-eye display being powered-on or the mounting device transitioning from one of an active orientation or a stowed orientation to the other.

Abstract: A display apparatus includes a beam combiner receiving a first image projected by a source, and a second image. The beam combiner combines the first image and the second image into a third image. A variable mask is configured to mask portions of the second image from the beam combiner. A controller is configured to shape the variable mask according to the content of the first image.