Display method

An apparatus for a head mounted display (“HMD”), the apparatus comprising:

• an illumination module for launching display light along a forward propagating path within an eyepiece;
• an end reflector disposed at an opposite end of the eyepiece from the illumination module to reflect back a private portion of the display light along a reverse propagating path;
• a beam splitter disposed in the forward propagating path between the end reflector and the illumination module for directing a public portion of the display light traveling along the forward propagating path out an external scene-side of the eyepiece, passing the private portion of the display light traveling along the forward propagating path to the end reflector, and directing the private portion of the display light traveling along the reverse propagating path out an eye-ward side of the eyepiece;
• projection optics that include a selectable blocking element to selectively block the public portion of the display light from being directed out the external scene-side of the eyepiece;
• a selectable waveplate retarder disposed within the eyepiece in the forward propagating path between the illumination module and the beam splitter, the selectable waveplate retarder causing the public portion of the display light to have a first polarization orientation when receiving a first signal and causing the private portion of the display light to have a second polarization orientation when receiving a second signal;
• and
• a fixed polarization rotator disposed in the forward propagating path and in the reverse propagating path between the beam splitter and the end reflector,
• wherein the public portion of the display light is launched by the illumination module during a first time period and the private portion of the display light is launched by the illumination module during a second time period, and wherein the display light is polarized and the beam splitter is a polarizing beam splitter.

An apparatus comprising:

• an illumination module for launching display light along a forward propagating path within an eyepiece, wherein the display light is polarized;
• an end reflector disposed at an opposite end of the eyepiece from the illumination module to reflect back the display light along a reverse propagating path;
• a selectable waveplate retarder disposed within the eyepiece along the forward propagating path, wherein the selectable waveplate retarder causes the display light to have a first polarization orientation when receiving a first signal and causes the display light to have a second polarization orientation when receiving a second signal;
• a polarizing beam splitter disposed within the eyepiece between the end reflector and the selectable waveplate retarder for directing the display light traveling along the forward propagating path out a first side of the eyepiece when the first signal is received and directing the display light traveling along the reverse propagating path out a second side of the eyepiece when the second signal is received;
• and
• a polarization rotator disposed between the polarizing beam splitter and the end reflector, wherein the display light includes public display light and private display light, and wherein the illumination module interlaces the private display light with the public display light, and wherein the public display light is output in sync with the first signal and the private display light is output in sync with the second signal.