Patent Description:
Heretofore, the development of a head-mounted display to be mounted on the head of a user for use has been underway (the head-mounted display will hereinafter be referred to as "HMD"). The HMD includes a display unit having a display device for being placed in front of the eyes of the user and a mount to be mounted on the head of the user, the mount supporting the display unit. Some HMDs have a fastening band for sandwiching the head of the user along the anterior-posterior directions (e.g., <CIT>). Other previously proposed arrangements are disclosed in <CIT> and <CIT>.

Some of the HMDs have a mechanism incorporated in the fastening band for adjusting the length of the fastening band. When the user matches the length of the fastening band to the size of its own head, the HMD is stably supported on the head. However, the conventional HMDs have a problem in that the process of adjusting the length of the fastening band is cumbersome. For example, if the length of the fastening band does not fit the head of the user, then the user attempts to adjust the length of the fastening band while the HMD is being mounted on the head. However, since the HMD tends to change in position or attitude during the adjusting process, the adjusting process becomes cumbersome.

A head-mounted display according to the definition of independent claim <NUM>.

The head-mounted display thus constructed allows the lengths of the fastening bands to be adjusted easily and can be mounted on the head of the user with increased stability.

<FIG> are views illustrating a head-mounted display <NUM> according to the embodiment of the present invention (the head-mounted display will hereinafter be referred to as "HMD"). <FIG> is a perspective view, <FIG> is a side elevational view, and <FIG> is a perspective view of the HMD <NUM> as viewed from an angle different from that of <FIG>. <FIG> is a set of views illustrating a rear support 22a of a second fastening band <NUM> to be described later, <FIG> being a view of a rear side of the rear support 22a and <FIG> a view illustrating a length adjusting mechanism M1 for the second fastening band <NUM>.

In the description which follows, Y1 and Y2 illustrated in the above figures represent an anterior direction and a posterior direction, respectively, X1 and X2 a leftward direction and a rightward direction, respectively, and Z1 and Z2 an upward direction and a downward direction, respectively.

The HMD <NUM> has a display unit <NUM> including a display device <NUM> (see <FIG>) on its front side. The display device <NUM> displays three-dimensional images. For example, the display device <NUM> displays an image for the right eye in its right area and an image for the left eye in its left area. The display device <NUM> may display three-dimensional images in a frame sequential format. The images displayed by the display device <NUM> are not limited to three-dimensional images, but may be two-dimensional images. The display device <NUM> may include a liquid crystal display device or an organic electroluminescence (EL) display device, but is not limited to any particular types. In an example of the HMD <NUM>, as illustrated in <FIG>, the display device <NUM> may be inclined with respect to a front surface of the display unit <NUM> or a rear surface of the display unit <NUM> (a surface facing the face of the user). As illustrated in <FIG>, the display unit <NUM> may have lenses <NUM> (see <FIG>) for increasing the viewing angle of the display device <NUM>. The display unit <NUM> has a frame <NUM> (see <FIG>) that supports the display device <NUM> and the lenses <NUM>, and a box-shaped housing <NUM> (see <FIG>) which houses therein the display device <NUM>, the lenses <NUM>, and the frame <NUM>.

As illustrated in <FIG>, the HMD <NUM> has a mount <NUM> for being mounted on the head of the user. The mount <NUM> has a first fastening band <NUM> and a second fastening band <NUM> which extend from the front side toward rear side of the HMD <NUM> and support the display unit <NUM>. As illustrated in <FIG>, the fastening bands <NUM> and <NUM> extend around the periphery of the head of the user when the HMD <NUM> is in use. The fastening bands <NUM> and <NUM> are placed on a rear side of the head of the user. The mount <NUM> has a front support <NUM> to be described later. The front support <NUM>, the first fastening band <NUM>, and the second fastening band <NUM> sandwich the head of the user along the anterior-posterior directions. In the example illustrated in <FIG>, the fastening bands <NUM> and <NUM> extend rearwardly from the front support <NUM>. In a plan view of the HMD <NUM>, the front support <NUM> and the first fastening band <NUM> are of an annular shape, and the front support <NUM> and the second fastening band <NUM> are also of an annular shape.

At least a portion of the first fastening band <NUM> is made of an elastically expandable material. The first fastening band <NUM> can elastically be expanded in its lengthwise direction as its material is expanded. In other words, when the material of the first fastening band <NUM> is expanded, the size of the annular shape made up of the front support <NUM> and the first fastening band <NUM> is varied. The second fastening band <NUM> is made of a material which is less expandable than the material of the first fastening band <NUM>. As described later, the second fastening band <NUM> has a mechanism M1 (see <FIG>) for adjusting its length. As a result, when the mechanism M1 adjusts the length of the second fastening band <NUM>, the size of the annular shape made up of the front support <NUM> and the second fastening band <NUM> is adjusted. When the user is to mount the HMD <NUM> on its own head, the user initially tentatively secures the position and attitude of the HMD <NUM> using the first fastening band <NUM>, and then can adjust the length of the second fastening band <NUM> while the HMD <NUM> is being tentatively secured. Therefore, when the user adjusts the length of the second fastening band <NUM>, the position and attitude of the HMD <NUM> is prevented from being varied, allowing the user to adjust the length of the second fastening band <NUM> easily. For example, since the HMD <NUM> is tentatively secured by the first fastening band <NUM>, the user can adjust the length of the second fastening band <NUM> using its both hands. Furthermore, as the second fastening band <NUM> is made of a material less expandable than the first fastening band <NUM>, the second fastening band <NUM> is mounted on the head of the user with increased stability.

When the first fastening band <NUM> is in its free state (when the elastic material thereof is not expanded), the first fastening band <NUM> is positioned within the second fastening band <NUM>. When the user is to use the HMD <NUM>, the user elastically expands the first fastening band <NUM>, increasing the size of the annular shape made up of the first fastening band <NUM> and the front support <NUM>, so that the user can mount them on the head. Thereafter, the user operates the mechanism M1 to adjust the length of the second fastening band <NUM>, reducing the size of the annular shape made up of the second fastening band <NUM> and the front support <NUM>, so that the user can secure them on the head.

The material of the first fastening band <NUM> may be rubber, for example. An example of the material of the second fastening band <NUM> is a resin such as plastics. The material of the second fastening band <NUM> may be a metal. Preferably, the material of the second fastening band <NUM> is not only less expandable than the material of the first fastening band <NUM>, but also more rigid than the material of the first fastening band <NUM>.

According to an example of the HMD <NUM>, the first fastening band <NUM> is made of an elastically expandable material in its entirety. According to another example of the HMD <NUM>, only a portion of the first fastening band <NUM> may be made of an elastically expandable material so that the first fastening band <NUM> can be expanded in its lengthwise direction. For example, the first fastening band <NUM> may have an unexpandable portion (a portion held against the rear side of the head of the user) in its rear portion, and side portions (portions held against the right and left sides of the head of the user) made of an expandable material.

As described above, the second fastening band <NUM> has the mechanism M1 for adjusting the length thereof (the mechanism M1 will hereinafter be referred to as "length adjusting mechanism"). In the example illustrated in <FIG>, the second fastening band <NUM> has a rear support 22a in its rear portion which is held against the rear side of the head of the user. The rear support 22a has a case <NUM> housing the length adjusting mechanism M1 (see <FIG>) therein. The rear support 22a preferably has a cushion 22b (see <FIG>) on an inner surface thereof (a surface to be held against the rear side of the head of the user).

The second fastening band <NUM> in the example described herein has left and right frames 22c. The frames 22c are made of the material (e.g., plastics) which is less expandable than the material of the first fastening band <NUM>, as described above. The left and right frames 22c extend from the front side to rear side of the HMD <NUM>, and are connected respectively to the left and right ends of the rear support 22a. In the example described herein, the frames 22c extend rearwardly from the right and left sides of the front support <NUM> and have rear portions fitted in the case <NUM> of the rear support 22a.

The length adjusting mechanism M1 is preferably arranged such that the rear support 22a will move equally with respect to the left and right frames 22c. With this arrangement, the position of the rear support 22a is prevented from being shifted to the right or left. According to an example of the HMD <NUM>, as illustrated in <FIG>, racks 22d are formed on rear portions of the frames 22c. The rack 22d of the right frame 22c and the rack 22d of the left frame 22c are disposed so as to face each other in the vertical, namely up-down directions. The rear support 22a includes a rotatable operating member 22e (the operating member 22e will hereinafter be referred to as "length adjusting member"). The length adjusting member 22e is disposed between the racks 22d of the two frames 22c, and a gear (not illustrated) engaging the racks 22d is coupled to the length adjusting member 22e. According to this structure, when the gear rotates, the rear support 22a moves equally with respect to the left and right frames 22c, causing the right and left portions of the second fastening band <NUM> to contract or expand equally. In other words, the rear support 22a moves along the anterior-posterior directions equally with respect to the left and right frames 22c. The length adjusting member 22e is coupled to both of the two frames 22c. Specifically, the gear of the length adjusting member 22e is held in engagement with both of the gears of the two frames 22c. Therefore, since the position of the rear support 22a with respect to both of the two frames 22c can be adjusted simply by operating the single length adjusting member 22e, the process of adjusting the length of the second fastening member <NUM> is made easy. As a result, the size of the annular shape made up of the front support <NUM> and the second fastening band <NUM> can easily be adjusted (increased and reduced).

The length adjusting mechanism M1 should preferably have a stopper mechanism for allowing the gear of the length adjusting member 22e to rotate in a direction to contract the frames 22c and locking the gear against rotation in the opposite direction. The length adjusting mechanism M1 should also preferably have an operating member (hereinafter referred to as "stopper canceling member") for canceling the locking of the gear against rotation (stopper) by the stopper mechanism in response to an operation of the user. Inasmuch as the second fastening band <NUM> is not extended unless the stopper is canceled by operating the stopper canceling member, the second fastening band <NUM> of the HMD1 is mounted in position with increased stability. In the example illustrated in <FIG>, the rear support 22a includes a stopper canceling member 22f exposed on its rear surface. The stopper canceling member 22f is coupled to a stopper which is held in engagement with the gear disposed between the racks 22d for preventing the gear from rotating. The stopper is released out of engagement with the gear when the stopper canceling member 22f is operated (pushed or slid).

The first fastening band <NUM> should also preferably be adjustable in length. A length adjusting mechanism for the first fastening band <NUM> may include a surface fastener, a buckle, or a ratchet mechanism, for example. According to an example of the first fastening band <NUM>, the length adjusting mechanism is provided on each of the right and left sides of the first fastening band <NUM>, thereby preventing the elastic force of the first fastening band <NUM> from becoming uneven on the right and left sides of the first fastening band <NUM>. In the example illustrated in <FIG>, the foremost portion of the first fastening band <NUM> is supported by a pin (not illustrated) mounted on the front support <NUM>, and the first fastening band <NUM> has an adjuster 21a reversed rearwardly and folded back from the pin. The adjuster 21a is detachably disposed on a side of the first fastening band <NUM>. A surface fastener, for example, is attached to the side of the side of the first fastening band <NUM> and the adjuster 21a. By adjusting the length of the adjuster 21a (the length from the pin to the end of the adjuster 21a), it is possible to adjust the length of the first fastening band <NUM> (the size of the annular shape made up of the front support <NUM> and the first fastening band <NUM>). This can increase or reduce the range in which the first fastening band <NUM> made of the above material (the elastically expandable material) is expandable.

The HMD <NUM> according to the example described herein has the front support <NUM> as described above. As illustrated in <FIG>, the front support <NUM> is coupled to an upper portion of the display unit <NUM>. The front support <NUM> extends upwardly and rearwardly obliquely from the display unit <NUM>. When the HMD <NUM> is in use, the front support <NUM> is held against the forehead of the user (see <FIG>). The front support <NUM> is less expandable than the first fastening band <NUM> and more rigid than the first fastening band <NUM>. As illustrated in <FIG>, the front support <NUM> is preferably formed in a plate-like shape and curved so that its central portion along the left-right directions bulges forwardly, thereby making itself mountable on the forehead of the user with increased stability. Preferably, a cushion 23f (see <FIG>) is attached to a rear surface of the front support <NUM> (a surface to be held against the forehead of the user).

The first fastening band <NUM> and the second fastening band <NUM> extend rearwardly from the front support <NUM>. Specifically, the fastening bands <NUM> and <NUM> are connected to the left and right side portions of the front support <NUM>. According to an example of the HMD <NUM>, as illustrated in <FIG>, each of the first fastening band <NUM> and the second fastening band <NUM> is connected to the front support <NUM>. According to another example of the HMD <NUM>, the second fastening band <NUM> may be connected to the front support <NUM>, and the first fastening band <NUM> may be connected to sides (specifically, the frames 22c) of the second fastening band <NUM>. As described in detail later, the display unit <NUM> is adjustable in its position relative to the front support <NUM>. According to this structure wherein the fastening bands <NUM> and <NUM> are directly or indirectly connected to the front support <NUM> rather than the display unit <NUM>, the user is able to adjust the position of the display unit <NUM> while the HMD <NUM> is being mounted on its head using the front support <NUM> and the fastening bands <NUM> and <NUM>.

In the example of the HMD <NUM>, as illustrated in <FIG>, the front support <NUM> is formed in a plate-like shape and the fastening bands <NUM> and <NUM> are connected to right and left edges of the front support <NUM>. Particularly, the front support <NUM> has a joint <NUM> disposed centrally on its lower end and coupled to the display unit <NUM>. The front support <NUM> also has a plate-like main body 23a extending upwardly from the joint <NUM> and spreading along the rightward and leftward directions. When the HMD <NUM> is in use, the main body 23a is held against the forehead of the user. As illustrated in <FIG>, the main body 23a should preferably be curved so that its central portion along the left-right directions bulges forwardly. The main body 23a thus arranged is disposed along the forehead of the user when the HMD <NUM> is in use, increasing the stability with which the HMD <NUM> is mounted in place. The fastening bands <NUM> and <NUM> are connected to right and left edges of the main body 23a. With this structure, since the force by which the fastening bands <NUM> and <NUM> hold the head is easier to act on the main body 23a in other words, the forehead of the user, the stability with which the HMD <NUM> is mounted in place is further increased. The second fastening band <NUM> may be connected to the right and left edges of the main body 23a of the front support <NUM>, whereas the first fastening band <NUM> may be connected to the sides (specifically, the frames 22c) of the second fastening band <NUM>. In this case, too, the force by which the fastening bands <NUM> and <NUM> hold the head is easier to act on the forehead of the user, increasing the stability with which the HMD <NUM> is mounted in place.

In the example of the HMD <NUM>, as described above, each of the first fastening band <NUM> and the second fastening band <NUM> extends rearwardly from the front support <NUM>. This structure makes it easier to keep the length of the first fastening band <NUM> than a structure wherein the first fastening band <NUM> is connected to the frames 22c of the second fastening band <NUM>, for example. As a result, since the first fastening band <NUM> is allowed to expand by an increased amount, it is easier to tentatively secure the HMD <NUM> using the first fastening band <NUM>. For example, the user can mount the first fastening band <NUM> on its head by expanding the first fastening band <NUM> without using the adjuster 21a. As illustrated in <FIG>, the second fastening band <NUM> in the example described herein extends rearwardly from the lower portion 23b of the main body 23a of the front support <NUM>. The first fastening band <NUM> extends rearwardly from a position higher than the position where the second fastening band <NUM> is connected. In the exampled described herein, the first fastening band <NUM> extends rearwardly from an upper portion 23c (see <FIG>) of the main body 23a of the front support <NUM>. According to an example of the second fastening band <NUM>, the frames 22c may be integrally formed with the lower portion 23b of the main body 23a, thereby simplifying the structure of the mount <NUM>.

As illustrated in <FIG>, in the example of the HMD <NUM>, the first fastening band <NUM> and the second fastening band <NUM> extend rearwardly and downwardly from the front side of the HMD <NUM>. More specifically, the first fastening band <NUM> and the second fastening band <NUM> extend rearwardly and downwardly obliquely from the front support <NUM>. In other words, the direction along which the first fastening band <NUM> extends and the direction along which the second fastening band <NUM> extends are inclined to a horizontal direction H so that the positions of their rear portions are lower than the positions of their front portions. Here, the horizontal direction H is a direction perpendicular to the display device <NUM>. The head of the user generally has a portion bulging rearwardly. The fastening bands <NUM> and <NUM> thus arranged make it possible to have their rear portions placed on a lower portion (a position lower than the bulging portion) of the rear side of the head of the user. As a consequence, even if the display unit <NUM> is heavy, the position of the display unit <NUM> is prevented from being lowered because the positions of the rear portions of the fastening bands <NUM> and <NUM> do not move upwardly as they are caught by the bulging portion of the head. In the example described herein, the rear support 22a of the second fastening band <NUM> is held against the lower portion of the rear side of the head of the user.

In the example of the HMD <NUM>, the second fastening band <NUM> is positioned beneath the first fastening band <NUM>. Therefore, the rear portion of the second fastening band <NUM> can reliably be caught by the bulging portion of the head compared with a structure wherein the second fastening band <NUM> is positioned above the first fastening band <NUM>. The second fastening band <NUM> is made of a material less expandable than the first fastening band <NUM> and has the mechanism M1 for adjusting its own length. Consequently, the second fastening band <NUM> can hold the head of the user more firmly than the first fastening band <NUM>. Since the rear portion of the second fastening band <NUM> which has such high holding power is reliably caught by the bulging portion of the head, the position of the display unit <NUM> is more reliably prevented from being lowered. As illustrated in <FIG>, in the example of the HMD <NUM>, the rear portion of the second fastening band <NUM> has a lower end <NUM> disposed at a position lower than the lower surface of the display unit <NUM>. In the example of the HMD <NUM>, the second fastening band <NUM> is inclined more downwardly than the first fastening band <NUM>.

The first fastening band <NUM> and the second fastening band <NUM> may not necessarily be limited to the above layout. For example, the second fastening band <NUM> may be positioned upwardly of the first fastening band <NUM>. In this case, the first fastening band <NUM> may extend rearwardly and downwardly obliquely from the front side of the HMD <NUM>, whereas the second fastening band <NUM> may extend horizontally.

As described above, the second fastening band <NUM> in the example described herein has the rear support 22a in its rear portion. The rear support 22a has the case <NUM> housing the length adjusting mechanism M1 therein. This structure increases the weight of the rear portion of the second fastening band <NUM> compared with a structure wherein a length adjusting mechanism is provided on a side of the second fastening band <NUM>, for example. As a result, it is easy to keep a balance between the weight of the front portion (display unit <NUM>) of the HMD <NUM> and the weight of the rear portion of the HMD <NUM>, preventing the position of the display unit <NUM> from being lowered.

As illustrated in <FIG>, the second fastening band <NUM> in the example has counterweights 22i in its rear portion. This structure makes it easy to increase the weight of the rear portion of the second fastening band <NUM>. In the example illustrated in <FIG>, the counterweights 22i are housed in the case <NUM>. The plural (two in the example illustrated in <FIG>) counterweights 22i that are disposed in the case <NUM> are horizontally spaced from each other. In the example illustrated in <FIG>, the counterweights 22i are disposed in right and left portions of the case <NUM>. According to an example, the counterweights 22i include members separate from the case <NUM>, and should preferably be made of a material different from the case <NUM>. More specifically, the counterweights 22i are made of a material which is denser than the material of the case <NUM>. This makes it easier to increase the weight of the rear portion of the second fastening band <NUM>. For example, the material of the counterweights 22i is a metal. However, the material of the counterweights 22i is not limited to a metal, but may be the same as the material of the case <NUM>, for example. The counterweights 22i may be integrally formed with the case <NUM>. Counterweights may be mounted on the rear portion of the first fastening band <NUM>. In this case, it is also easy to keep a balance between the weight of the front portion (display unit <NUM>) of the HMD <NUM> and the weight of the rear portion of the HMD <NUM>.

As described above, the mount <NUM> has the front support <NUM> on its front side. The front support <NUM> is connected to the upper portion of the display unit <NUM>. The display unit <NUM> is movable along the anterior-posterior directions relatively to the mount <NUM>, i.e., the front support <NUM>, thereby allowing the user to adjust the distance between the display device <NUM> and the eyes. When the user moves the display unit <NUM> forwardly, the user can see downwardly while keeping the HMD <NUM> mounted on the head. For example, if the HMD <NUM> is used in playing a game, then the user can see a game controller held by hands.

<FIG> are views illustrating a mechanism for guiding the display unit <NUM> along directions of relative movement. These figures illustrate a first guide <NUM> provided on the mount <NUM> and a second guide <NUM> provided on the display unit <NUM>. <FIG> is a plan view, <FIG> a side elevational view, and <FIG> a cross-sectional view taken along line VII - VII of <FIG>.

The mount <NUM> has a plate-like frame <NUM>. The frame <NUM> has a fixture 60a fixed in the front support <NUM>. The first guide <NUM> is provided on the frame <NUM>. Specifically, the frame <NUM> has a support 60b extending forwardly from the fixture 60a. The first guide <NUM> is mounted on the support 60b. The first guide <NUM> and the support 60b are disposed on an upper portion of the housing <NUM> of the display unit <NUM>. The display unit <NUM> has the second guide <NUM> on the upper portion of the housing <NUM>. The second guide <NUM> guides the first guide <NUM> for movement along the anterior-posterior directions.

As illustrated in <FIG>, the second guide <NUM> has a base <NUM>. According to an example of the second guide <NUM>, the base <NUM> is of a plate-like shape. The first guide <NUM> is disposed above the base <NUM>, for example. The first guide <NUM> may be disposed below the base <NUM>. The base <NUM> has side guides 71R and <NUM> on its right and left sides. The first guide <NUM> is disposed between the two side guides 71R and <NUM>. Specifically, the right side guide 71R and the left side guide <NUM> are positioned respectively on the right and left sides of the first guide <NUM>, and extend along the edges of the first guide <NUM>. The side guides 71R and <NUM> and the base <NUM> are integrally formed of a metal, for example.

The second guide <NUM> has guide rails formed separately from the side guides 71R and <NUM> and the base <NUM>. The second guide <NUM> has guide rails 73R and <NUM> respectively on the right and left sides thereof. The guide rails 73R and <NUM> are disposed between the side guides 71R and <NUM> and the edges of the first guide <NUM>. The guide rails 73R and <NUM> are made of a resin such as plastics, for example. The first guide <NUM> is also made of a resin such as plastics, for example. The guide rails 73R and <NUM> may be made of a metal. As illustrated in <FIG>, the guide rails 73R and <NUM> may be formed in vertically sandwiching relation to the edges of the first guide <NUM>, thereby reducing friction between the first guide <NUM> and the second guide <NUM>.

The guide rail <NUM> has a portion 73b (see <FIG>) capable of bearing a force directed toward the edge of the first guide <NUM> from an outer side (specifically, a left side) of the guide rail <NUM> in the horizontal directions (the portion will hereinafter be referred to as "pressed portion 73b"). The guide rail <NUM> has the pressed portion 73b disposed midway along its longitudinal directions. Preferably, the guide rail <NUM> should have a plurality of pressed portions 73b spaced from each other along its longitudinal directions.

As illustrated in <FIG>, the side guides 71R and <NUM> are of a wall-like shape, and are disposed along the guide rails 73R and <NUM>. The side guide <NUM> has a hole 71a defined therein through which a portion of the side surface of the guide rail <NUM> is exposed. The guide rail <NUM> can be pressed toward the edge of the first guide <NUM> through the hole 71a in the side guide <NUM>. In other words, a portion of the side surface of the guide rail <NUM> which corresponds to the hole 71a serves as the pressed portion 73b. The side guide <NUM> may have a plurality of holes 71a spaced from each other along the longitudinal directions of the guide rail <NUM>.

The base <NUM> and the guide rail <NUM> are arranged so that the position of the guide rail <NUM> can be slightly moved along the horizontal directions before a fixed member <NUM> to be described later is fixed to the second guide <NUM>. The position of the guide rail <NUM> along the horizontal directions is secured by a separate member from the base <NUM> and the guide rail <NUM>. The member which secures the position of the guide rail <NUM> should preferably have a portion held in contact with the pressed portion 73b. The position of the guide rail <NUM> along the horizontal directions is secured while the guide rail <NUM> is held in contact with the edge of the first guide <NUM>. The "separate member" referred to above includes a structure (e.g., a screw or a fixed member to be described later) or a material (e.g., an adhesive) which can be moved separately from the base <NUM> and the guide rail <NUM> before it is used to secure the guide rail <NUM>.

As described above, the second guide <NUM> has the base <NUM> having the side guides 71R and <NUM> and the guide rail <NUM> positioned between the side guide <NUM> and the edge of the first guide <NUM>. The guide rail <NUM> has the pressed portion 73b capable of bearing a force directed toward the first guide <NUM> from the outer side in the horizontal directions. The second guide <NUM> has the separate member from the base <NUM> and the guide rail <NUM> for securing the position of the guide rail <NUM> with respect to the base <NUM> along the horizontal directions.

The second guide <NUM> of the above structure can be manufactured as follows: The guide rails 73R and <NUM> are placed inwardly of the side guides 71R and <NUM>. Thereafter, the first guide <NUM> is placed between the guide rails 73R and <NUM>. While the pressed member 73b of the left side guide rail <NUM> is being pushed toward the edge of the first guide <NUM>, the position of the guide rail <NUM> along the horizontal directions is secured by the separate member from the base <NUM> and the guide rail <NUM>. In this manner, the distance between the guide rails 73R and <NUM> can be matched to the width of the first guide <NUM>, allowing the first guide <NUM> to move linearly along the anterior-posterior directions.

As illustrated in <FIG> and <FIG>, the second guide <NUM> has the separate fixed member <NUM> from the base <NUM> and the guide rail <NUM>. The fixed member <NUM> has pressing portions 74a. The pressing portions 74a are positioned in the holes 71a in the side guide <NUM> and held in contact with the pressed portions 73b of the guide rail <NUM>. The fixed member <NUM> has a fixed portion 74b that is fixed to the base <NUM>. The fixed member <NUM> thus constructed makes it easy to secure the position of the guide rail <NUM>.

The fixed portion 74b is of a plate-like shape, for example. The pressing portions 74a project upwardly or downwardly from the edge of the fixed portion 74b. The fixed member <NUM> has the plural pressing portions 74a spaced from each other along the lengthwise directions of the guide rail <NUM>. As illustrated in <FIG>, the fixed portion 74b is disposed on the lower surface of the base <NUM> and fixed to the base <NUM>. The fixed portion 74b is welded to the base <NUM>, for example. The fixed portion 74b may be fused or bonded to the base <NUM>. The guide rail <NUM> may be fixed to the base <NUM> by an adhesive rather than the plate-like fixed member <NUM>. For example, an adhesive may be introduced through the holes 71a to fill the space between the guide rail <NUM> and the side guide <NUM>. The adhesive which is solidified functions as a fixed member.

As described above, the base <NUM> and the guide rail <NUM> are arranged so that the position of the guide rail <NUM> can be slightly moved along the horizontal directions. For example, the base <NUM> has holes defined therein and the guide rail <NUM> has protrusions fitted in the holes. The size of the holes along the horizontal directions is slightly larger than the size of the protrusions of the guide rail <NUM>. Before the position of the guide rail <NUM> is secured by the fixed member <NUM>, therefore, the position of the guide rail <NUM> can be slightly moved. As illustrated in <FIG>, the side guide <NUM> has a retaining wall 71b. The guide rail <NUM> is vertically sandwiched by the base <NUM> and the retaining wall 71b. Consequently, before the position of the guide rail <NUM> is secured by the fixed member <NUM>, the guide rail <NUM> is retained by the base <NUM> while being slightly movable.

The side guide 71R is of the same structure as the side guide <NUM> except that the side guide <NUM> has the holes 71a defined therein. The side guide 71R may also have holes 71a defined therein. In the example described above, the second guide <NUM> which has the guide rails <NUM> and 73R and the fixed member <NUM> is provided on the display unit <NUM>, and the first guide <NUM> is provided on the mount <NUM>. However, the second guide <NUM> which has the guide rails <NUM> and 73R and the fixed member <NUM> may be provided on the mount <NUM>, and the first guide <NUM> may be provided on the display unit <NUM>.

<FIG> and <FIG> are schematic views illustrating a mechanism for locking the display unit <NUM> and the mount <NUM> against relative movement along the anterior-posterior directions (the mechanism will hereinafter be referred to as "position adjusting mechanism M2"). <FIG> is a view of the position adjusting mechanism M2, as viewed along the direction IX in <FIG>, illustrating a locking member <NUM> and a locked member <NUM>.

According to an example of the HMD <NUM>, the locking member <NUM> may be mounted on the frame <NUM>. The locking member <NUM> and a lower portion (the support 60b described above) of the frame <NUM> are coupled to the display unit <NUM>. The locking member <NUM> and the lower portion of the frame <NUM> are guided for movement relative to the display unit <NUM> by the second guide <NUM> described above which is provided on the display unit <NUM>.

The display unit <NUM> in the example illustrated in <FIG> has the locked member <NUM> on an upper portion thereof. According to an example of the position adjusting mechanism M2, as illustrated in <FIG>, the locking member <NUM> has an engaging portion 24a on a lower side thereof. The engaging portion 24a includes a plurality of combtooth-shaped convexities arrayed along the anterior-posterior directions (Y1 - Y2 directions). The locked member <NUM> is disposed on a lower side of the locking member <NUM> and has an engaged portion 31a formed on an upper side thereof. The engaged portion 31a also includes a plurality of convexities which engage the plural convexities composing of the engaging portion 24a. The locked member <NUM> is movable between a locked position and an unlocked position. The locked position refers to the position of the locked member <NUM> illustrated in <FIG>. When the locked member <NUM> is in the locked position, the engaged portion 31a of the locked member <NUM> engages the engaging portion 24a of the locking member <NUM>, preventing the locking member <NUM> and the frame <NUM> from moving relatively to the display unit <NUM>. The unlocked position refers to a position spaced in the leftward direction (D2 direction in <FIG>) from the position of the locked member <NUM> illustrated in <FIG>. When the locked member <NUM> is in the unlocked position, the engaged portion 31a of the locked member <NUM> disengages from the engaging portion 24a of the locking member <NUM>, allowing relative movement of the display unit <NUM>.

The display unit <NUM> in the example illustrated in <FIG> has a lock canceling member <NUM> responsive to a user's operation. The lock canceling member <NUM> is provided on a lower surface of the display unit <NUM> (see <FIG>). The display unit <NUM> has a joint member <NUM> for transmitting movement of the lock canceling member <NUM> to the locked member <NUM>. The joint member <NUM> has an upper end coupled to the locked member <NUM> and a lower end coupled to the lock canceling member <NUM>. The locked member <NUM> is moved between the locked position and the unlocked position in response to movement of the lock canceling member <NUM>. The joint member <NUM> in the example illustrated herein includes a lever movable about a shaft 32a. When the lock canceling member <NUM> slides in the rightward direction (D1 direction in <FIG>) while the locked member <NUM> is in the locked position, the locked member <NUM> moves in the leftward direction (D2 direction in <FIG>) toward the unlocked position. The display unit <NUM> can now be adjusted in its relative position with respect to the front support <NUM> (more specifically, the frame <NUM>). Since the locked member <NUM> is biased toward the locked position, when the force tending to cause the locked member <NUM> to slide in the rightward direction (D1 direction in <FIG>) is canceled, the locked member <NUM> moves in the rightward direction toward the locked position, and the lock canceling member <NUM> moves in the opposite leftward direction (D2 direction in <FIG>). The relative position of the display unit <NUM> with respect to the front support <NUM> is now prevented from being adjusted.

According to the example of the HMD <NUM>, the position adjusting mechanism M2 is able to switch between a state wherein the position of the display unit <NUM> with respect to the front support <NUM> can be adjusted and a state wherein the position of the displayed unit <NUM> with respect to the front support <NUM> is prevented from being adjusted in response to the operation of the lock canceling member <NUM> by the user.

As illustrated in <FIG>, a light shielding member may be mounted on the display unit <NUM>. The light shielding member should preferably be made of a flexible material. For example, the light shielding member is made of an elastomer.

As illustrated in <FIG>, the display unit <NUM> has side guards <NUM> extending rearwardly from the sides of the display unit <NUM> as an example of the light shielding member. The side guards <NUM> block light on the right and left sides of the HMD <NUM> when the HMD <NUM> is in use.

As illustrated in <FIG>, the frame <NUM> of the display unit <NUM> has openings 13a defined in the right and left sides of a rear surface thereof. The lenses <NUM> and the display device <NUM> are disposed on the inside of the openings 13a. The user can see images displayed on the display device <NUM> through the openings 13a. A recess 13b which is open rearwardly and downwardly is defined between the left and right openings 13a. When the HMD <NUM> is in use, the nose of the user is positioned in the recess 13b. As illustrated in <FIG>, a light shielding member <NUM> may also be disposed in the recess 13b. According to an example of the light shielding member <NUM>, the light shielding member <NUM> is disposed so as to cover the inside of the recess 13b when the display unit <NUM> is viewed from behind. The light shielding member <NUM> prevents ambient light from reaching the eyes of the user through the gap between the inner surface of the recess 13b and the nose of the user when the HMD1 is in use.

According to an example of the light shielding member <NUM>, as illustrated in <FIG>, the light shielding member <NUM> is of a sheet-like shape covering (closing) the recess 13b. The sheet-like light shielding member <NUM> is formed of a flexible material, for example. As illustrated in <FIG>, the light shielding member <NUM> may be integrally formed with the side guards <NUM>. The light shielding member <NUM> may be a member separate from the side guards <NUM>, which is mounted on the frame <NUM> of the display unit <NUM>. In this case, the light shielding member <NUM> may be detachably mounted on the frame <NUM>. The light shielding member <NUM> thus arranged makes it possible to vary the position of the light shielding member <NUM> in the recess 13b, or stated otherwise, the position of the light shielding member <NUM> along the anterior-posterior directions, depending on the size of the nose of the user. In the example illustrated in <FIG>, the light shielding member <NUM> is of a sheet-like shape and has a slit 42c defined centrally therein which extends vertically. The light shielding member <NUM> thus constructed prevents itself from obstructing the way in which the HMD <NUM> is comfortably mounted when the HMD <NUM> is in use.

According to another example of the light shielding member <NUM>, the light shielding member <NUM> is formed of a cushioning material and disposed in covering relation to the inside of the recess 13b. Stated otherwise, the cushioning light shielding member <NUM> is disposed in the recess 13b and attached to the inner surface of the recess 13b. The light shielding member <NUM> thus arranged also prevents ambient light from reaching the eyes of the user through the gap between the inner surface of the recess 13b and the nose of the user.

<FIG> is a view illustrating a modification of the light shielding member. In the example illustrated in <FIG>, the display unit <NUM> has the side guards <NUM> and the light shielding member <NUM>. In the illustrated example, the side guards <NUM> have curved edges 41a. The curved edges 41a reduce the discomfort which is caused by the edges 41a of the side guards <NUM> that are pressed against the face of the user when the HMD <NUM> is mounted on the head. The light shielding member <NUM> has a right side portion 42a and a left side portion 42b opposite the slit 42c. The right side portion 42a and the left side portion 42b should preferably have curved edges 42d. The curved edges 42d reduce the discomfort which is caused by the edges 42d of the light shielding member <NUM> that are pressed against the nose of the user when the HMD <NUM> is mounted on the head.

The mount <NUM> may have a front pad on its front side for contacting the front side of the head of the user. The front pad should preferably have a cushion. The front pad is provided on the rear side of the upper portion 23c of the front support <NUM>. The front pad should preferably be supported in a manner to make the angle of the front pad in the anterior-posterior directions adjustable. The front pad thus arranged makes it possible to vary the angle of the front pad depending on the shape and size of the head of the user.

<FIG> is a set of views illustrating an example of a structure which is capable of adjusting the angle of a front pad <NUM>. <FIG> is a side elevational view, partly cut away, of the front pad <NUM>. <FIG> is a plan view of the front pad <NUM>.

The front pad <NUM> has a bracket 25a. The bracket 25a is formed of a material that is of relatively high rigidity, such as plastics or metal. According to an example of the front pad <NUM>, the bracket 25a is of a plate-like shape. A cushion 25b referred to above is attached to the bracket 25a. The bracket 25a has shafts 25c on its right and left sides. The shafts 25c are supported in the front support <NUM>, for example. The shafts 25c are positioned on a lower portion of the front pad <NUM> as viewed in side elevation. An upper portion of the front pad <NUM> can move about the shafts 25c in the anterior-posterior directions, thereby making it possible to adjust the angle of the front pad <NUM>.

As illustrated in <FIG>, the mount <NUM> has an operating member <NUM> for the user to move the front pad <NUM>. The operating member <NUM> is housed in the front support <NUM>. The operating member <NUM> is supported for sliding movement along the horizontal directions. The bracket 25a has pressed portions 25d projecting forwardly. The operating member <NUM> has pressing surfaces 27a for pressing the pressed portions 25d. The pressing surfaces 27a are inclined to vary the position of the pressed portions 25d of the bracket 25a in the anterior-posterior directions depending on the position of the operating member <NUM> in the horizontal directions. The operating member <NUM> has an operating portion 27b exposed on the outer surface of the front support <NUM>. With this structure, when the user moves the position of the operating member <NUM> along the horizontal directions through the operating portion 27b, the angle of the front pad <NUM> is varied.

The HMD <NUM> in the example described herein has a plurality of light emitters <NUM> which include light-emitting elements such as LEDs or the like. As described later, when the HMD <NUM> is in use, an information processing apparatus to which the HMD <NUM> is connected detects the positions of the plural light emitters <NUM> through a camera, for thereby detecting the orientation of the head of the user and controlling images displayed on the display device <NUM> and objects displayed on the display device <NUM> depending on the orientation of the head. According to an example of the HMD <NUM>, as illustrated in <FIG> and <FIG>, the plural light emitters <NUM> are disposed in spaced apart relation to each other on the display unit <NUM> (in <FIG> and <FIG>, the light emitters <NUM> are illustrated hatched for clarification). In the illustrated example, the plural light emitters <NUM> are disposed in outer peripheral regions of the front surface of the display unit <NUM>. Since the spacing between the light emitters <NUM> thus arranged is large, the accuracy with which to detect the orientation of the head is increased. In the example illustrated in <FIG> and <FIG>, four light emitters <NUM> are disposed on the four corners of the front surface of the display unit <NUM>. More specifically, in the example illustrated in <FIG> and <FIG>, the light emitters <NUM> are disposed on the four corners of the front surface so that the light emitters <NUM> extend over both the front and side surfaces of the display unit <NUM>. Stated otherwise, the light emitters <NUM> are disposed obliquely to the front surface of the display unit <NUM> so as to face the outer sides of the outer edges of the front surface of the display unit <NUM>. With this layout of the light emitters <NUM>, it is easy for the information processing apparatus to detect light from the light emitters <NUM> through the camera. For example, even when the user faces in a direction different from the direction of the camera, the information processing apparatus can detect light from the light emitters <NUM>.

According to an example of the HMD <NUM>, as illustrated in <FIG>, the HMD <NUM> has light emitters <NUM> on its rear portion (in <FIG>, the light emitters <NUM> are illustrated hatched for clarification). In the example illustrated in <FIG>, the plural (two in <FIG>) light emitters <NUM> are provided on the rear support 22a of the second fastening band <NUM>. The plural light emitters <NUM> are spaced from each other in the horizontal directions. With this layout of the light emitters <NUM>, it is easy to detect light from the light emitters <NUM> through the camera. For example, even when the head of the user faces in a direction opposite to the direction of the camera, light from the light emitters <NUM> can be detected.

The layout of the light emitters <NUM> is not limited to those described above, but may be modified appropriately. For example, the display unit <NUM> may have only two light emitters <NUM> spaced from each other in the horizontal directions. Alternatively, the display unit <NUM> may have only two light emitters <NUM> spaced from each other in the vertical directions. The light emitters <NUM> may not necessarily be provided on the rear support 22a.

<FIG> is a view illustrating an example of the manner in which the HMD <NUM> is used. A camera <NUM> is connected to an information processing apparatus <NUM>. As described above, the information processing apparatus <NUM> detects the positions of the plural light emitters <NUM> through the camera <NUM>, and detects the orientation of the head of the user on the basis of the positions of the plural light emitters <NUM>. In the example of the manner in which the HMD <NUM> is used, the information processing apparatus <NUM> generates or corrects a moving-image signal depending on the orientation of the user, and outputs the moving-image signal to the HMD <NUM>. The information processing apparatus <NUM> may output a moving-image signal to a display device <NUM> such as a television or the like in addition to the HMD <NUM>. In this case, the moving-image signal output to the HMD <NUM> and the moving-image signal output to the display device <NUM> may be different from each other. For example, the information processing apparatus <NUM> may output a moving-image signal for a two-dimensional image to the display device <NUM>, and may output a moving-image signal for a three-dimensional image to the display device <NUM> of the HMD <NUM>. The moving-image signals of those two types may be generated by a dedicated apparatus which is different from the information processing apparatus <NUM>. The display unit <NUM> of the HMD <NUM> may be provided with sensors such as an acceleration sensor, a gyro sensor, etc. The information processing apparatus <NUM> may generate moving-image signals on the basis of the outputs from the sensors. The information processing apparatus <NUM> may generate moving-image signals on the basis of a signal from an operating device <NUM> which is manually operated by the user.

As described above, the HMD <NUM> has the first fastening band <NUM> and the second fastening band <NUM> which extend from the front side toward rear side of the HMD <NUM> for being fastened to the head of the user. At least a portion of the first fastening band <NUM> is made of an elastically expandable material. The second fastening band <NUM> is made of a material which is less expandable than the above material of the first fastening band <NUM> and includes the mechanism M1 for adjusting its length. The display unit <NUM> includes the display device <NUM> and is supported by the first fastening band <NUM> and the second fastening band <NUM>. With this HMD <NUM>, when the user is to mount the HMD <NUM> on its head, the user initially tentatively secures the position and attitude of the HMD <NUM> using the first fastening band <NUM>, and then can adjust the length of the second fastening band <NUM> while the HMD <NUM> is being tentatively secured. Therefore, when the user adjusts the length of the second fastening band <NUM>, the position and attitude of the HMD <NUM> is prevented from being varied, allowing the user to adjust the length of the second fastening band <NUM> easily. Furthermore, as the second fastening band <NUM> is made of a material less expandable than the first fastening band <NUM>, the second fastening band <NUM> is mounted on the head of the user with increased stability.

The present invention is not limited to the HMD <NUM> described above, but can be modified in various ways.

For example, the first fastening band <NUM> and the second fastening band <NUM> may extend rearwardly from the display unit <NUM> rather than the front support <NUM>. Alternatively, one of the first fastening band <NUM> and the second fastening band <NUM> may extend rearwardly from the display unit <NUM>, whereas the other band may extend rearwardly from the front support <NUM>.

Claim 1:
A head-mounted display (<NUM>) comprising:
a first fastening band (<NUM>) for being fastened to a head of a user, the first fastening band including at least a portion made of an elastically expandable material and extending rearwardly from a front side of the head-mounted display;
a second fastening band (<NUM>) for being fastened to the head of the user, the second fastening band being made of a material which is less expandable than the material of the first fastening band, including a mechanism (M1) for adjusting the length of the second fastening band, and extending rearwardly from the front side of the head-mounted display; and
a display unit (<NUM>) including a display device and supported by at least one of the first fastening band and the second fastening band;
characterized in that the first fastening band is positioned within the second fastening band, when the first fastening band is in its free state.