Patent Description:
<CIT> discloses a head-mounted display provided with a suspender mounted on a user's head, a display device for displaying images, and a connecting member for connecting the suspender and the display device. The connecting member has a two-stage hinge element that allows the connecting member to rotate freely with respect to the suspender and the display device to rotate freely with respect to the connecting member. After mounting the suspender to the user's head, the user can move the display device to a position in front of the eyes by grasping the display device by hand and rotating the connecting member with respect to the suspender.

<CIT> relates to a head-mounted display having a main body with a display device mounted and a head mounting unit that is attached to one side of the main body and is worn on the head of the user. The head mounting unit includes a head wearing member worn on the head of the user, a hinge coupling member hinged to the head wearing member, an angle adjusting member coupled to the main body and movably coupled to the hinge coupling member, and a specific locking member provided on the head fitting member for locking the angle adjusting member.

However, a gap sometimes occurs between the display device and the user's face in the technique disclosed in Patent Literature <NUM>. There is a problem that external light entering through a gap between the display device and the user's face causes a noise component, which leads to a degradation in the quality of a display image.

A first aspect of a present embodiment has been made in view of the above problem, and an object of the present embodiment is to provide a head-mounted display capable of improving the quality of a display image by suppressing the influence of external light.

According to the invention, a head-mounted display according to claim <NUM> is provided.

The first aspect of a present embodiment makes it possible to achieve the effect that the quality of a display image can be improved by suppressing the influence of external light.

A configuration of a head-mounted display <NUM> according to the present embodiment will be described below with reference to <FIG>. The head-mounted display <NUM> is a device mounted on a head <NUM> so as to cover the left and right eyes of a user, and displays prescribed information to the user. For example, the head-mounted display <NUM> displays a stereoscopic image to the user by displaying parallax images corresponding to the left and right eyes as virtual images. In the following description, the up-down direction, the front-rear direction, and the left-right direction of the head-mounted display <NUM> are defined with reference to the up-down direction, the front-rear direction, and the left-right direction of the head <NUM> in a state in which the head-mounted display <NUM> is mounted.

The head-mounted display <NUM> includes a display device <NUM>, a hinge <NUM>, and a headband <NUM>.

The display device <NUM> generates parallax images corresponding to the left and right eyes of the user and guides the display light corresponding to the parallax images to the user's eyes. The display device <NUM> includes a device body <NUM>, left and right display units <NUM> and 12R, and a cushion material <NUM>.

The device body <NUM> is formed of, for example, a rectangular shaped box that is horizontally long in the left-right direction of the head <NUM>. The device body <NUM> may be curved to correspond to the curve of a user's face <NUM>. The device body <NUM> is formed of a material such as synthetic resin from the standpoint of strength and weight reduction.

The rear-end side of the device body <NUM> is an opposing part 11a facing the user's face <NUM>. In contrast, the front-end side of the device body <NUM> is a protruding part 11b separated from the opposing part 11a to the front by a certain distance. Space is provided between the opposing part 11a and the protruding part 11b to accommodate the left and right display units <NUM> and 12R.

The left and right display units <NUM> and 12R are accommodated inside the device body <NUM>. The left and right display units <NUM> and 12R corresponding to the left and right eyes of the user are arranged spaced apart in the left-right direction. The left display unit <NUM> is placed to the left side from the center of the device body <NUM>, and the right display unit 12R is placed to the right side from the center of the device body <NUM>.

The left and right display units <NUM> and 12R display images corresponding to the right and left eyes (parallax images). That is, the left display unit <NUM> displays a display image corresponding to the left eye, and the right display unit 12R displays a display image corresponding to the right eye.

Each of the display units <NUM> and 12R is provided with a display element and an optical system. The display element generates a display image and outputs display light corresponding to the display image. For example, a display panel such as a liquid crystal panel or an organic electro-luminescence (EL) panel can be used as the display element.

The optical system guides display light output by the display element to the user's eye as a display image. The optical system includes one or more optical elements selected from a group including mirrors, lenses, and the like. Lenses 12La and 12Ra arranged so as to be positioned in front of the user's eyes are provided on the opposing part 11a facing the user's face <NUM> in the device body <NUM>, and display light passing through the lenses 12La and 12Ra is guided to the user's eyes. When the user wears the head-mounted display <NUM>, the display device <NUM> is brought into contact with the user's face <NUM> so as to cover the user's eyes. The user can view virtual images that are the display images generated by the display units <NUM> and 12R, at the front side in front of the user.

The configuration of the display units <NUM> and 12R is an example and the display units <NUM> and 12R are not limited to this configuration. For example, the display units <NUM> and 12R need not have respective display elements, and may be configured to share a single display element. In this case, the single display element need not be built into the device body <NUM> and an external display device may be utilized.

The cushion material <NUM> is provided over the entire peripheral edge of the opposing part 11a. When the head-mounted display <NUM> is mounted on the user's head <NUM>, the cushion material <NUM> becomes a contact area with the user's face <NUM>. The cushion material <NUM> is formed of a material with elasticity such as polyurethane foam.

The head-mounted display <NUM> needs to be mounted in a position in front of the user's eyes and further needs to be mounted in a position close to the user's eyes. When the device body <NUM> comes into direct contact with the user's face <NUM>, the rigid device body <NUM> compresses the user's face <NUM>. For this reason, it is possible to reduce the compression of the user's face <NUM> caused by the device body <NUM> by providing the cushion material <NUM> in the opposing part 11a.

The shape of the human face <NUM> varies but the shape of the device body <NUM> is fixed. For this reason, the shape of the device body <NUM> does not fit the shape of the user's face <NUM> depending on the user, and external light may enter through a gap between the opposing part 11a of the device body <NUM> and the user's face <NUM>. This external light becomes a noise component and leads to a degradation in the quality of a display image. Accordingly, it is possible to reduce the influence of external light by filling a gap between the opposing part 11a and the user's face <NUM> with the cushion material <NUM> arranged at the peripheral edge of the opposing part 11a.

The hinge <NUM> is provided in the headband <NUM>. The display device <NUM> is connected to the hinge <NUM>. The hinge <NUM> is rotatably configured around a rotating shaft extending in the left-right direction, and the display device <NUM> is rotatably connected to the headband <NUM> via the hinge <NUM>. For this reason, the display device <NUM> rotates in a relative manner with respect to the headband <NUM> around the rotating shaft of the hinge <NUM>.

The hinge <NUM> is attached to the lower part of the headband <NUM> at the front-end side. In addition, the hinge <NUM> is connected to an upper surface 11c of the device body <NUM> of the display device <NUM>. Accordingly, the display device <NUM> is suspended at the front end of the headband <NUM> via the hinge <NUM>. The user can move the display device <NUM> away from the user's face <NUM> by rotating the display device <NUM> upward around the hinge <NUM>. The user can also move the display device <NUM> closer to the user's face <NUM> to thereby bring the display device <NUM> into contact with the user's face <NUM> by rotating the display device <NUM> downward around the hinge <NUM>. When the display device <NUM> is rotated downward, the user can smoothly rotate the display device <NUM> because a rotation moment described later acts on the display device <NUM>.

The headband <NUM> is mounted on the user's head <NUM> and supports the display device <NUM>. The headband <NUM> is an annular member and surrounds the entire circumference of the user's head <NUM>, specifically the forehead constituting part of the user's face <NUM>, the right side of the head, the back side of the head, and the left side of the head. The headband <NUM> has an adjustment mechanism that allows the circumferential length to be adjusted. This adjustment mechanism allows the user's head <NUM> to be tightened with appropriate force regardless of the size of the user's head <NUM>, which in turn allows the display device <NUM> to be stably mounted on the head <NUM>.

In the head-mounted display <NUM> according to present embodiment, the following two structures are adopted to suppress the influence of external light.

The first structure generates a rotation moment for pressing the display device <NUM> against the user's face <NUM>. The first structure for generating a rotation moment will be described below with reference to <FIG>.

The center of gravity Gr of the display device <NUM> is set forward from the hinge <NUM>, that is, set outward from the hinge <NUM> as viewed from the user's face <NUM>. A force Fg corresponding to the weight of the display device <NUM> acts vertically downward on the center of gravity Gr of the display device <NUM>. In this case, the force Fg can be considered separately as a first component force Fg1 along a line La passing through the center of gravity Gr from the rotation center of the display device <NUM> (that is, the rotation axis of the hinge <NUM>) and a second component force Fg2 along a line Lb perpendicular to the line La. Of the first component force Fg1 and the second component force Fg2, the second component force Fg2 along the line Lb causes the rotation moment to act in the direction in which the display device <NUM> is pressed against the user's face <NUM>.

Thus, the positional relationship between the center of gravity Gr of the display device <NUM> and the hinge <NUM> makes it possible to generate the rotation moment, which is caused by the weight of the display device <NUM>, in the display device <NUM>. This rotation moment allows the display device <NUM> to be pressed against the user's face <NUM>, and thus the cushion material <NUM> can be brought into close contact with the user's face <NUM>. This makes it possible to suppress a gap that has occurred between the cushion material <NUM> and the user's face <NUM>, thereby making it possible to suppress the influence of external light.

The magnitude of the rotation moment depends on the weight of the display device <NUM>. For this reason, it is possible to increase the force that presses the display device <NUM> against the user's face <NUM> by changing the specifications of the display device <NUM>. However, the display device <NUM> needs to be mounted on the user's head <NUM> and placed in a position in front of the eyes. That is, since the display device <NUM> is placed far from the neck that supports the human head <NUM>, even a slight increase in the weight of the display device <NUM> is a considerable burden on the user. Thus, it is preferable to set the magnitude of the rotation moment in consideration of the burden on the user.

In the present embodiment, the weight of the display device <NUM> is used as the structure for generating a rotation moment. The center of gravity Gr of the display device <NUM> is set forward from the hinge <NUM>. However, the center of gravity Gr of the display device <NUM> may be set backward from the hinge <NUM> depending on the structure of the head-mounted display <NUM>. For this reason, in a case where the attachment position of the hinge <NUM> with respect to the display device <NUM> can be adjusted, the attachment position may be adjusted such that the center of gravity Gr of the display device <NUM> is set forward from the hinge <NUM>. According to the invention, by adding a center of gravity adjusting member such as a weight to the display device <NUM>, the center of gravity of the composite body, which is configured of the display device <NUM> and the center of gravity adjusting member, is set forward from the hinge <NUM>.

In addition, the structure for generating a rotation moment is not limited to being caused by the weight of the display device <NUM>. For example, a torsion coil spring may be provided in the hinge <NUM>, and a biasing force generated by the torsion coil spring may generate a rotation moment for pressing the display device <NUM> against the user's face <NUM>.

The second structure suppresses the incidence of external light by using the cushion material <NUM> regardless of the shape of the user's face <NUM>, on the premise of the first structure that generates a rotation moment. The second structure that suppresses the incidence of external light by using the cushion material <NUM> will be described below with reference to <FIG>, <FIG>.

Since the lenses 12La and 12Ra that guide the display light to the user's eyes are arranged in the opposing part 11a of the device body <NUM>, there is no cushion material <NUM> in the lenses 12La and 12Ra. As described above, the cushion material <NUM> is provided around the lenses 12La and 12Ra, specifically at the peripheral edge of the opposing part 11a. The cushion material <NUM> has a function of reducing the pressure on the user's face <NUM> and a function of suppressing the incidence of external light.

In the present embodiment, the cushion material <NUM> includes an upper cushion part 15a positioned at the upper part of the peripheral edge of the opposing part 11a and a lower cushion part 15b positioned below the upper cushion part 15a. When the upper cushion part 15a and the lower cushion part 15b are compared with each other, they have different elastic moduli and thicknesses. The reason why the elastic modulus and the thickness are different between the upper cushion part 15a and the lower cushion part 15b will be described below.

The display device <NUM> and the headband <NUM> are connected via the hinge <NUM>. The rotation center of the display device <NUM> serves as the hinge <NUM>, more specifically, the rotating shaft of the hinge <NUM>. When a rotation moment is generated in the display device <NUM>, the amount of movement at the upper part of the display device <NUM> near the hinge <NUM> is small. In contrast, the amount of movement at the lower part of the display device <NUM> far from the hinge <NUM> is large.

For example, in the display device <NUM>, it is assumed that the elastic modulus and the thickness of the upper cushion part and the elastic modulus and the thickness of the lower cushion part are the same. In a case where the display device <NUM> is pressed against the user's face <NUM>, if the upper cushion part comes into contact with the forehead of the user first, the rotation of the display device <NUM> is prevented by the force that the upper cushion part receives from the forehead. For this reason, the lower cushion part does not come into contact with the cheek of the user, or even if the lower cushion part comes into contact with the cheek of the user, the force acting on the cheek becomes weak. Accordingly, there is a possibility that external light enters through a gap between the lower cushion part and the user's face <NUM>.

In view of the above circumstances, in the head-mounted display <NUM> according to the present embodiment, the elastic modulus and the thickness are different between the upper cushion part 15a and the lower cushion part 15b. Specifically, the lower cushion part 15b has a thickness that is set to be greater than that of the upper cushion part 15a. In addition, the lower cushion part 15b has an elastic modulus that is set to be the same as that of the upper cushion part 15a or smaller than that of the upper cushion part 15a.

The upper cushion part 15a is positioned at the upper part of the peripheral edge of the opposite part 11a, and is a part that is brought into contact with mainly the forehead of the user's face <NUM>. In contrast, the lower cushion part 15b is positioned at the lower part of the peripheral edge of the opposite part 11a, and is a part that is brought into contact with mainly the cheek of the user's face <NUM>. Specifically, the upper cushion part 15a and the lower cushion part 15b can be defined with reference to the lenses 12La and 12Ra that guide the display light to the user's eyes.

As illustrated in <FIG>, a boundary line L1 is defined with reference to the optical centers of the lenses 12La and 12Ra that guide the display light to the user's eyes. The cushion material <NUM> positioned above the boundary line L1 may be defined as the upper cushion part 15a, and the cushion material <NUM> positioned below the boundary line L1 may be defined as the lower cushion part 15b.

Further, as illustrated in <FIG>, a boundary line L2 is defined above the lenses 12La and 12Ra, and a boundary line L3 is defined below the lenses 12La and 12Ra. The cushion material <NUM> positioned above the boundary line L2 may be defined as the upper cushion part 15a, and the cushion material <NUM> positioned below the boundary line L3 may be defined as the lower cushion part 15b.

Further, as illustrated in <FIG>, the boundary line L2 is defined above the lenses 12La and 12Ra. The cushion material <NUM> positioned above the boundary line L2 may be defined as the upper cushion part 15a, and the cushion material <NUM> positioned below the boundary line L2 may be defined as the lower cushion part 15b.

Thus, the division between the upper cushion part 15a and the lower cushion part 15b is determined by considering the shape of the device body <NUM>, an average face shape that is statistically derived, or the like.

The elastic moduli of the upper cushion part 15a and the lower cushion part 15b may be the same; however, when the elastic moduli of the upper cushion part 15a and the lower cushion part 15b are made to be different as described above, it is possible to actively make the amount by which the cushion material <NUM> compresses more different between the upper side and the lower side of the display device <NUM>. That is, when the same force is applied, the amount by which the lower cushion part 15b compresses becomes greater than the amount by which the upper cushion part 15a compresses.

In <FIG>, "PF" is a line schematically illustrating the position of the user's face <NUM>. When the display device <NUM> is pressed against the user's face <NUM>, the user rotates the display device <NUM> downward around the hinge <NUM>, that is, rotates the display device <NUM> counterclockwise in the figure.

For example, as illustrated in <FIG>, a face shape is assumed in which a forehead position PF1 is positioned forward from a cheek position PF2. The distance Δb1 between the opposing part 11a and the cheek position PF2 is longer than the distance Δa1 between the opposing part 11a and the forehead position PF1. As described above, and according to the invention as claimed, the lower cushion part 15b has a thickness that is set to be greater than that of the upper cushion part 15a. For this reason, even when the upper cushion part 15a is in contact with the forehead of the user, the distance Δb1 between the opposing part 11a and the cheek position PF2 can be satisfied by the thickness of the lower cushion part 15b. This makes it possible to suppress a gap between the lower cushion part 15b and the cheek, thereby making it possible to suppress the possibility that external light enters through a gap.

According to a non-claimed example, and as illustrated in <FIG>, a face shape is assumed in which the cheek position PF2 is positioned forward from the forehead position PF1. The distance Δb2 between the opposing part 11a and the cheek position PF2 is shorter than the distance Δa1 between the opposing part 11a and the forehead position PF1. As described above, the lower cushion part 15b has an elastic modulus that is set to be the same as that of the upper cushion part 15a or smaller than that of the upper cushion part 15a. For this reason, when the lower cushion part 15b receives a force from the cheek, the lower cushion part 15b can be compressed according to the distance Δb2 between the opposing part 11a and the cheek position PF2. In a case where the lower cushion part 15b has an elastic modulus greater than that of the upper cushion part 15a, it is hard for the lower cushion part 15b to be compressed, which prevents the rotation of the display device <NUM>. For this reason, a gap may occur between the upper cushion part 15a and the forehead. In contrast, appropriate compression of the lower cushion part 15b allows the display device <NUM> to rotate until the upper cushion part 15a reaches the forehead, even if the lower cushion part 15b comes into contact with the cheek. This makes it possible to suppress a gap between the upper cushion part 15a and the forehead, thereby making it possible to suppress the possibility that external light enters through a gap.

In addition, in the configuration in which the display device <NUM> rotates around the hinge <NUM>, the amount of movement at the upper part of the device body <NUM> is small, while the amount of movement at the lower part of the device body <NUM> is large. In this respect, in the cushion material <NUM> of the present embodiment, the elastic modulus of the upper cushion part 15a is large and the amount by which the upper cushion part 15a compresses is suppressed. Accordingly, even if the upper cushion part 15a is compressed, the amount of compression is small. For this reason, it is possible to suppress the amount of movement at the lower side of the device body <NUM>. This makes it possible to adequately fill a gap between the opposing part 11a and the cheek in the range of the thickness to be set in the lower cushion part 15b.

Thus, according to the head-mount display <NUM> of the present invention, the lower cushion part 15b has a thickness that is set to be greater than that of the upper cushion part 15a. In addition, the lower cushion part 15b has an elastic modulus that is set to be the same as that of the upper cushion part 15a or smaller than that of the upper cushion part 15a. This makes it possible to suppress the influence of external light, thereby making it possible to improve the quality of a display image.

In addition, according to the present embodiment, the upper cushion part 15a is positioned above the left and right lenses 12La and 12Ra provided in the device body <NUM>. This makes it possible to suppress the influence of external light and appropriately reduce the pressure on the forehead and cheeks of the user.

In addition, according to the present embodiment, the center of gravity Gr of the display device <NUM> is positioned forward from the hinge <NUM> and below the hinge <NUM>. This makes it possible to appropriately generate a rotation moment for pressing the display device <NUM> against the user's face <NUM>.

In the head-mounted display <NUM> according to the present embodiment, it is preferable that the elastic modulus and the thickness of the upper cushion part 15a and the lower cushion part 15b be different from each other. This makes it possible to suppress the influence of external light, thereby making it possible to improve the quality of a display image. However, the upper cushion part 15a and the lower cushion part 15b may have the same elastic modulus, and the upper cushion part 15a and the lower cushion part 15b may differ only in thickness.

The above embodiment which has been described in detail is not limited to the configuration described above, and may be a modified example to the extent that it does not deviate from the scope of the present invention as defined by the appended claims.

Claim 1:
A head-mounted display (<NUM>) comprising:
a headband (<NUM>) configured to be mounted on a head of a user;
a hinge (<NUM>) provided in the headband (<NUM>); and
a display device (<NUM>) that is rotatably connected to the headband (<NUM>) via the hinge (<NUM>) and configured to be brought into contact with a face of the user so as to cover eyes of the user, wherein
the display device (<NUM>) includes:
a device body (<NUM>) on which a rotational moment acts in a direction toward the face (<NUM>) of the user around the hinge (<NUM>);
a cushion material provided at a peripheral edge of an opposing part facing the face (<NUM>) of the user in the device body (<NUM>) to be brought into contact with the face (<NUM>) of the user; and
a center of gravity adjusting member configured to set the center of gravity of a composite body, which is configured of the display device and the center of gravity adjusting member, forward from the hinge, wherein
the cushion material (<NUM>) includes:
an upper cushion part (15a) positioned at an upper part of the peripheral edge of the opposing part; and
a lower cushion part (15b) positioned below the upper cushion part (15a), wherein
the lower cushion part (15b) has a thickness greater than that of the upper cushion part (15a).