Head-mounted display apparatus

A head-mounted display apparatus for a viewer comprising:

• a) an optical imager having a display generator that is energizable to emit image-bearing light in a first direction and a compound prism that is configured to redirect the generated light in a second direction that is toward the viewer's eye and orthogonal to within +/−30 degrees relative to the first direction;
• b) a housing that is configured to form a sealed chamber that encloses at least the display generator of the optical imager and a control logic circuit, wherein the housing is further configured to expose, within the viewer field of view, at least a portion of the compound prism that extends from an orifice in the housing;
• c) a releasable coupling formed onto a cover element of the sealed chamber and configured to cooperate with a mounting fixture formed on headgear worn by the viewer for mounting the housing and suspending the exposed portion of the prism into the viewer field of view;
• and
• d) a sensor that is mounted within the sealed chamber and generates a signal related to a sensed condition in the field of view.

A method for display to a viewer, the method comprising:

• a) disposing, within a housing, a display generator that is energizable to emit image-bearing light in a first direction;
• b) extending, from the housing, a prism that is configured to guide the emitted light to a folding surface that redirects the emitted light in a second direction that is orthogonal to within +/−30 degrees relative to the first direction;
• and
• c) sealing the housing to enclose the display generator and form a sealed chamber by attaching a cover, wherein the cover further includes a coupling configured for releasable attachment to headgear worn by the viewer.