As Microsoft writes:
This discussion relates to complementary augmented reality. An augmented reality experience can include both real world and computer-generated content. For example, head-mounted displays (HMDs) (e.g., HMD devices), such as optically see-through (OST) augmented reality glasses (e.g., OST displays), are capable of overlaying computer-generated spatially-registered content onto a real world scene. However, current optical designs and weight considerations can limit a field of view (FOV) of HMD devices to around a 40 degree angle, for example. In contrast, an overall human vision FOV can be close to a 180 degree angle in the real world. In some cases, the relatively limited FOV of current HMD devices can detract from a user’s sense of immersion in the augmented reality experience. The user’s sense of immersion can contribute to how realistic the augmented reality experience seems to the user. In the disclosed implementations complementary augmented reality concepts can be implemented to improve a sense of immersion of a user in an augmented reality scenario. Increasing the user’s sense of immersion can improve the overall enjoyment and success of the augmented reality experience.
Read more here: mspoweruser.com/microsoft-patents-holodeck-style-projection-room-patent/