The patent describes an "Obstacle avoidance apparatus and obstacle avoidance method", and it's surprisingly straightforward for a patent.
Search for Document Number 20130328928.
An obstacle detecting unit detects an obstacle for a user wearing a head mounted display from an image of the outside world. A distance calculating unit calculates the distance from a detected obstacle to the user wearing the head mounted display. An obstacle replacing unit replaces the detected obstacle with a virtual object. A virtual object synthesizing unit generates a virtual object at a position within a virtual space displayed on the head mounted display, in which the position is determined according to the distance to the obstacle.
Misc (things I found very interesting)
 2. Description of the Related Art
 It is common that a user plays a game while wearing a head mounted display connected to a game device on the head, watching the screen displayed on the head mounted display, and operating a controller or the like. With a typical stationary display connected to a game device, since the user's field of vision includes the outside of the display's screen, the user may not be able to concentrate on the screen or the user's feeling of being immersed in the game may be reduced. Wearing a head mounted display, on the other hand, the user only sees images displayed on the head mounted display, so that the user feels more immersed in the world of the images and the entertainment capabilities of the game will be enhanced.
 However, since a user wearing a head mounted display cannot see the outside world, the user may bump into an obstacle around the user or may knock something off a desk when stretching a hand or moving the user's body during game play.
SUMMARY OF THE INVENTION
 The present invention has been made in view of such a problem, and a purpose thereof is to provide an obstacle avoidance apparatus and an obstacle avoidance method that can avoid the situation where a user wearing a head mounted display bumps into an obstacle.
 To solve the problem above, an obstacle avoidance apparatus of an embodiment of the present invention comprises: an obstacle detecting unit configured to detect an obstacle for a user wearing a head mounted display from an image of the outside world; an obstacle replacing unit configured to replace the detected obstacle with a virtual object; and a virtual object synthesizing unit configured to generate the virtual object within a virtual space displayed on the head mounted display.
 Another embodiment of the present invention relates to an obstacle avoidance method. The method comprises: detecting an obstacle for a user wearing a head mounted display from an image of the outside world; replacing the detected obstacle with a virtual object; and generating the virtual object within a virtual space displayed on the head mounted display.
 Optional combinations of the aforementioned constituting elements, and implementations of the invention in the form of methods, apparatuses, systems, computer programs, data structures, and recording media may also be practiced as additional modes of the present invention.
 Position information of the user can be measured using a position sensor, such as a global positioning system (GPS), embedded in the head mounted display 100 or placed externally. Also, posture information, such as the orientation or tilt of the user's head wearing the head mounted display 100, can be measured using a posture sensor embedded in the head mounted display 100 or placed externally
 The main body 110 includes a display, a position information acquisition sensor, a posture sensor, and a communication apparatus. The frontal region contact unit 120 and temporal region contact unit 130 include a biological information acquisition sensor that can measure the user's biological information, such as the body temperature, pulse, blood components, perspiration, brain waves, and cerebral blood flow.
 The head mounted display 100 may further comprise a camera for capturing an image of a user's eye. With the camera mounted on the head mounted display 100, the line of sight, pupil movement, and blinking of the user can be detected.
 When the obstacle is a movable object such as a human or an animal, the obstacle replacing unit 630 selects a movable object, such as an avatar or a robot, as a virtual object by which the obstacle is replaced, and the virtual object synthesizing unit 640 generates within the virtual space a movable object that moves according to the movement of the real obstacle.
BRIEF DESCRIPTION OF THE DRAWINGS
 Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:
 FIG. 1 is an outline view of a head mounted display;
 FIG. 2 is a functional configuration diagram of a head mounted display;
 FIG. 3 is a configuration diagram of an obstacle avoidance system according to the present embodiment;
 FIG. 4 is a diagram for describing an environment around a user wearing a head mounted display;
 FIG. 5 is a functional configuration diagram of an obstacle avoidance apparatus according to the present embodiment;
 FIG. 6 is a flowchart that shows a procedure of obstacle avoidance performed by the obstacle avoidance apparatus shown in FIG. 5;
 FIG. 7 is a diagram for describing an exemplary virtual object displayed on a head mounted display to avoid an obstacle; and
 FIG. 8 is a diagram for describing another exemplary virtual object displayed on a head mounted display to avoid an obstacle.