Patent ID: 12204102

DESCRIPTION OF EMBODIMENT

FIG.1is a diagram schematically illustrating an overview of an appearance configuration of a head-mounted display100according to an embodiment, and shows that a user1is wearing the head-mounted display100. It is assumed that the head-mounted display100according to the embodiment is a non-see-through head-mounted display. Therefore, when the user1wears the head-mounted display100, the head-mounted display100blocks out an outside world from a vision of the user1as illustrated inFIG.1. This allows the user1to focus on content videos presented by the head-mounted display100, thus enhancing so-called “immersion.”

The head-mounted display100includes a housing110and a fitting120. The fitting120is a member used to fasten the housing110to a head of the user1and can be implemented, for example, by a tightening or elastic belt. The housing110accommodates a central processing unit (CPU) which is not shown, a movie presentation section130a, and an audio presentation section130b. The movie presentation section130aincludes, for example, a liquid crystal display (LCD) or organic electro-luminescence (EL). The audio presentation section130bincludes, for example, a speaker and an earphone. It should be noted that, in the present specification, a “video” includes a “movie,” timely successive images, and “audio” that is played in synchronism with or independently of the movie. The head-mounted display100further includes an outside world measurement section140that measures information on an outside world of the housing110. The outside world measurement section140will be described in detail later.

FIG.2is a diagram schematically illustrating a functional configuration of the head-mounted display100according to the embodiment. The head-mounted display100includes an information presentation section130, the outside world measurement section140, a notification information detection section150, a notification section160, a position measurement section170, a control section180, and a video playing section190.

FIG.2illustrates a functional configuration for enabling the head-mounted display100according to the embodiment to notify an outside world condition to the user1. Other part of the configuration is not shown. InFIG.2, each of the elements described as a functional block for performing various processing tasks can be formed with a CPU, a main memory, and other large scale integrations (LSIs) in terms of hardware. In terms of software, on the other hand, each of the elements is implemented by a program loaded into the main memory. Therefore, it is understood by those skilled in the art that these functional blocks can be implemented in various ways by hardware alone, software alone, or a combination thereof and are not limited to any one of them.

The video playing section190plays the content video presented to the user1. The video playing section190plays the content acquired via an unshown memory card slot or universal serial bus (USB) or by wireless means such as wireless fidelity (Wi-Fi) (registered trademark). The information presentation section130includes the movie presentation section130aand the audio presentation section130bdescribed above, presenting the video played by the video playing section190to the user1. The information presentation section130causes the movie presentation section130ato present movies, still images, and other information and the audio presentation section130bto present audio information. The information presentation section130functions as a user interface for presenting information generated by the head-mounted display100to the user1.

The outside world measurement section140measures information on an outside world of the housing110. The outside world measurement section140is provided at a position on the outside of the housing110of the head-mounted display100that matches the position in which the movie presentation section130ais accommodated. Therefore, when the head-mounted display100is worn by the user1, the outside world measurement section140can measure outside world information in the direction of line of sight of the user1.

The outside world measurement section140can be implemented, for example, by a camera designed to measure visible radiation or an infrared camera designed to measure infrared radiation. It should be noted that the outside world measurement section140may be a stereo camera with at least two cameras. This makes it possible to acquire depth information of a subject by analyzing information measured by the outside world measurement section140.

The notification information detection section150detects whether or not any notification information to be notified to the user1is contained in the information measured by the outside world measurement section140. “Information to be notified” refers to information used to identify the extent to which the user1is allowed to move. More specifically, if the outside world measurement section140is a stereo camera, the notification information detection section150detects still objects that stand still of all subjects measured by the outside world measurement section140, a stereo camera, as notification information. This can be implemented by a known 3D image analysis technology.

The notification section160notifies the user1when notification information is detected by the notification information detection section150. For example, the notification section160may show, on the information presentation section130, notification information to the effect that a still object exists in the outside world in the form of a message. Alternatively, a window showing a video of the still object may be displayed on the information presentation section130. The notification section160may cause the information presentation section130to play notification information to the effect that a still object exists in the outside world in the form of audio information. Alternatively, the notification section160may cause the information presentation section130to play a warning tone indicating that a still object exists in the outside world. If the head-mounted display100has a vibrator (not shown), the user1may be notified by vibration.

The position measurement section170detects where the head-mounted display100exists. More specifically, the position measurement section170measures the position of the head-mounted display100in the space where the head-mounted display100exists. The position measurement section170includes, for example, an acceleration sensor and an angular speed sensor, thus detecting a relative position of the head-mounted display100with respect to a reference point determined in advance by the user1.

The control section180comprehensively controls each of the different sections of the head-mounted display100described above. The control section180is implemented as a result of execution of the operating system of the head-mounted display100by the CPU (not shown) of the head-mounted display100.

FIG.3is a diagram schematically illustrating a scene in which the head-mounted display100according to the embodiment is used. The example inFIG.3shows that the user1is wearing the head-mounted display100in a room where a desk200exists.

We consider, for example, a case in which the user1wears the head-mounted display100and plays a 3D game. In this case, the user1advances through the game by manipulating a controller of a gaming device (not shown). The head-mounted display100presents a video that changes in accordance with the progress of the game to the user1.

As described above, the head-mounted display100according to the embodiment is a non-see-through head-mounted display that presents 3D videos full of immersion to the user1. Therefore, what the user1perceives from the videos presented by the head-mounted display100is a realistic experience. In some cases, the user1may move his or her head or body reflexively. When the user uses the head-mounted display100in a relatively small space such as a room at home, the head-mounted display100can be made easier to use if the extent to which the user1is allowed to move, i.e., the area within which the user1can enjoy the game, can be presented. This can enhance the usability of the head-mounted display100.

For this reason, when the notification information detection section150detects a still object, the notification to the user1by the notification section160may be triggered by the fact that the distance between the head-mounted display100and the still object becomes shorter than a given reference distance.

Here, the term “given reference distance” refers to a “notification reference distance” that serves as a reference for deciding whether or not the notification section160should notify notification information to the user1. Although may be determined experimentally in consideration of the anticipated manner in which the head-mounted display100is used and so on, the notification reference distance is, for example, one meter. The notification section160notifies the user1accordingly if the distance between the still object and the head-mounted display100becomes shorter than one meter. This allows the user1to recognize that he or she has come close to the boundary of the movable area.

If the movement of the head-mounted display100is negligible, for example, as when the user1uses the head-mounted display100seated, the still object is shot as an immobile subject in the video shot by the outside world measurement section140. In such a case, the notification information detection section150need only identify the still object by analyzing the video measured by the outside world measurement section140. Further, if the outside world measurement section140is a stereo camera, the notification information detection section150can estimate the distance to the still object by analyzing the video measured by the outside world measurement section140.

In contrast, if the user1uses the head-mounted display100, for example, while standing and moving, the movement of the head-mounted display100is not negligible. In this case, analyzing the video measured by the outside world measurement section140alone may lead to low accuracy in identifying the still object. The reason for this is that the position of the still object, despite standing still object, changes in the video measured by the outside world measurement section140because of the movement of the head-mounted display100.

Therefore, the notification section160may acquire the distance between the head-mounted display100and the still object based on the position of the head-mounted display100detected by the position measurement section170. In this case, the user1determines a reference point for position measurement in advance before using the head-mounted display100. In the example shown inFIG.3, the user1determines a point P, a point in the desk200, as the reference point P.

As illustrated inFIG.3, the user1establishes a Cartesian coordinate system300with its origin set at an arbitrary point in the space where the user1and the desk200exist. The position of the reference point P can be set uniquely as position coordinates of the Cartesian coordinate system300. InFIG.3, the coordinates of the reference point P are set at P(X1, Y1, Z1). The user1moves the head-mounted display100to the position of the reference point P first and then instructs the head-mounted display100to start measurement. This can be accomplished, for example, by pressing a measurement start button (not shown) attached to the housing110.

The position measurement section170includes an acceleration sensor and an angular speed sensor. The position measurement section170integrates output values of the sensors after being instructed to start measurement by the user1, thus allowing for calculation of the relative position of the head-mounted display100with respect to the reference point P. Further, the position measurement section170can acquire the position coordinates of the head-mounted display100in the Cartesian coordinate system300by merging the relative position of the head-mounted display100with the coordinates P(X1, Y1, Z1) of the reference point P. In particular, if the user1specifies the reference point P as a point on the still object, the notification section160can calculate the distance between the still object and the head-mounted display100without using the coordinates P(X1, Y1, Z1) of the reference point P.

By acquiring the position coordinates of the head-mounted display100, i.e., the movement of the head-mounted display100, the notification information detection section150can identify the reason why the subject measured by the outside world measurement section140moved in the video. This provides improved accuracy in extraction of still objects by the notification information detection section150. Further, the distance between the still object and the head-mounted display100can be acquired with higher accuracy than by acquiring depth information of the subject through analysis of information shot by the outside world measurement section140, a stereo camera.

FIG.4is a flowchart describing an information processing flow handled by the head-mounted display100according to the embodiment. The processes in this flowchart begin, for example, when the head-mounted display100is powered on.

The outside world measurement section140measures outside world information in the direction of line of sight of the user1when the head-mounted display100is worn by the user1(S2). While a still object remains unfound by the notification information detection section150through analysis of the video measured by the outside world measurement section140(N in S4), the outside world measurement section140continues with measurement of the outside world.

When a still object is found in the video measured by the outside world measurement section140(Y in S4), the notification information detection section150sets the detected still object as notification information (S6). The notification section160acquires a distance L from the head-mounted display100to the still object (S8) based on the position of the head-mounted display100detected by the position measurement section170.

When the distance L from the head-mounted display100to the still object is equal to or longer than a given reference distance LT(N in S10), the notification section160returns to step S8to continue with acquisition of the distance L. If the distance L from the head-mounted display100to the still object is shorter than the given reference distance LT(Y in S10), the notification section160notifies the user via the information presentation section130that a still object is close (S12).

While the user1continues to use the head-mounted display100(N in S14), the head-mounted display100returns to step S2to continue with the series of processes described above. When the user1stops using the head-mounted display100(Y in S14), the processes in this flowchart are terminated.

As described above, the head-mounted display100according to the embodiment can provide a technology for notifying an outside world condition to the user1wearing the non-see-through head-mounted display.

In particular, if the head-mounted display100worn by the user1comes close to a still object in the outside world, information to that effect is presented on the information presentation section130of the head-mounted display100. This allows the user1to find out that he or she has come close to the boundary of the area within which the user1is allowed to freely move even with the non-see-through head-mounted display100on.

Thus, the present invention has been described based on the embodiment. It is to be understood by those skilled in the art that the embodiment is illustrative, that combinations of components and processes thereof can be modified in various ways, and that these modification examples also fall within the scope of the present invention.

In the above description, a case was described in which the notification information detection section150detected a still object in outside world information measured by the outside world measurement section140as notification information. Instead or in addition thereto, the notification information detection section150may detect, as notification information, an object moving at a given speed or more in outside world information measured by the outside world measurement section140.

For example, if the user1uses the head-mounted display100according to the embodiment in a room with an inwardly opening door, the area within which the user1is allowed to freely move changes when the door is opened by somebody other than the user1. That is, if the inwardly opening door opens, this means that the door enters into the room, thus resulting in a smaller area within which the user1is allowed to move. For this reason, the unshown notification information detection section150detects a moving object in the outside world information measured by the outside world measurement section140, notifying the result thereof to the user1.

This allows the head-mounted display100according to a modification example to notify any change in the outside world condition to the user1wearing the non-see-through head-mounted display. Even in the event of a change in the area within which the user1is allowed to move, the head-mounted display100can adaptively notify the boundary thereof to the user1.

REFERENCE SIGNS LIST

100Head-mounted display,110Housing,120Fitting,130Information presentation section,130aMovie presentation section,130bAudio presentation section,140Outside world measurement section,150Notification information detection section,160Notification section,170Position measurement section,180Control section,190Video playing section,200Desk,300Cartesian coordinate system.

INDUSTRIAL APPLICABILITY

The present invention is applicable to information processing technologies for head-mounted displays.