A wearable optical see-through head-mounted display projects three-dimensional images onto the real world. The technology research goal is to place sounds and images in any location around the wearer, making virtual objects seem as if they actually exist. A unique brightness control system has been also investigated to deliver stably visible images even when the wearer moves between environments with different levels of brightness, such as indoors and outdoors.
The system recognizes the environment around the wearer and displays delay and distortion free images in sync with the wearer’s movements. In addition, it delivers sounds via headphones that make it seem as if they are originating from specific locations around the wearer. This is done by simulating difference in sound level, timing and the HRTFs (Head Related Transfer Functions) of sounds reaching each ear.
The visibility of the display can be maintained even in bright outdoor locations by sensing ambient brightness and adjusting the transmittance of the display's dimming control element accordingly. The research is on-going to improve usability such as quick adjustment of see-through transmittance taking just two seconds to change from the lightest to darkest setting and five seconds from the darkest to lightest setting.