Display device

Abstract

This display device comprises: a first guide mechanism having a first main guide part and a first sub-guide part extending in a first direction in which a pair of optical elements are arranged; and a second guide mechanism having a second main guide part and a second sub-guide part extending in a second direction along an optical axis of the optical elements. The first main guide part is positioned at one side in a third direction crossing both the first direction and the second direction in relation to the optical axis, and the first sub-guide part is position at the other side. The second main guide part is positioned outside the optical axis in the first direction, and the length of the second sub-guide part in the second direction is shorter than the length of the second main guide part in the second direction. If viewed in the second direction, the shortest distance between the first main guide part and the second sub-guide part is shorter than both the shortest distance between the first main guide part and the second main guide part and the shortest distance between the first sub-guide part and the second main guide part.

Description

display device

[0001] The present invention relates to a display device such as a head-mounted display (hereinafter referred to as HMD) that displays an image to a user using optical elements.

[0002] An HMD has an image display means equipped with optical elements such as a display and lenses, and uses these to display images to a user. Recently, HMDs have been equipped with or developed with visual adjustment functions such as an IPD (Inter Pupilary Distance) adjustment function and a diopter adjustment function. The IPD adjustment function adjusts the image interval between images displayed to the user's right and left eyes. By adjusting the image interval to match the interpupillary distance between the user's right and left eyes, the visibility of the images can be improved. The diopter adjustment function adjusts the focal length of the images displayed to the user. In an HMD, diopter adjustment according to the user's visual acuity allows the image to be focused without the need for vision correction devices such as glasses. Furthermore, dynamically adjusting the focal length of the displayed image according to the depth of the object the user is gazing at is expected to improve the visibility of near objects and reduce motion sickness. An example of an HMD equipped with an IPD adjustment function and a diopter adjustment function is the HMD described in Patent Document 1. In both adjustment functions, each visual adjustment is performed by mechanically moving an optical element.

[0003] Japanese Patent Application Publication No. 9-68670

[0004] The IPD adjustment function and diopter adjustment function described above displace the optical element in different directions. Therefore, when both functions are installed in an HMD, their movement mechanisms must be positioned so as not to interfere with each other. In this case, depending on the positioning of the movement mechanism, the display unit of the HMD may become large or may have a protruding portion relative to the surface shape of the area around the eyes of the user's face, which may interfere with the area around the eyes of the user's face and reduce wearability.

[0005] An object of the present invention is to provide a technique for preventing an increase in size of a display device and a decrease in wearability in a display device in which optical elements can be adjusted to be displaced in a plurality of different directions.

[0006] In order to achieve the above object, a display device of the present invention is a display device having a pair of display units that display images to left and right eyeballs, respectively, the pair of display units having: a pair of optical elements arranged corresponding to the left and right eyeballs; a first guide mechanism that holds the pair of optical elements so as to change the spacing between the pair of optical elements in a first direction that is the arrangement direction of the pair of optical elements; and a second guide mechanism that holds the pair of optical elements so as to change the positions of the pair of optical elements in a second direction that is the optical axis direction of the optical elements, the first guide mechanism having a first main guide portion and a first sub-guide portion that extend in the first direction, the second guide mechanism having a second main guide portion and a second sub-guide portion that extend in the second direction, the first main guide portion being located on one side of an optical axis of the optical element in a third direction that intersects with both the first direction and the second direction, the first sub-guide portion being located on the other side of the optical axis in the third direction, and the second main guide portion being located outside the optical axis in the first direction, The length of the second sub-guide portion in the second direction is shorter than the length of the second main guide portion in the second direction, and when viewed in the second direction, the shortest distance between the first main guide portion and a guide portion of the first sub-guide portion that is closer to the second sub-guide portion and the second sub-guide portion is shorter than both the shortest distance between the first main guide portion and the second main guide portion and the shortest distance between the first sub-guide portion and the second main guide portion.

[0007] According to the present invention, it is possible to prevent an increase in size of the display device and a decrease in ease of wearing the display device in which the optical element can be adjusted to be displaced in a plurality of different directions.

[0008] FIGS. 1A and 1B are diagrams showing the configuration of an HMD 1 according to a first embodiment. FIGS. 2A and 2B are diagrams showing the configuration of a display unit of the HMD 1 according to the first embodiment. FIGS. 3A and 3B are diagrams showing the features, actions, and effects of the HMD 1 according to the first embodiment. FIGS. 4A and 4B are diagrams showing the configuration of an HMD 2 according to a second embodiment. FIGS. 5A and 5B are diagrams showing the configuration of a display unit of the HMD 2 according to the second embodiment. FIGS. 6A and 6B are diagrams showing the features, actions, and effects of the HMD 2 according to the second embodiment.

[0009] The following examples will exemplarily illustrate embodiments of the present disclosure. However, the configurations disclosed in the following examples, such as the functions, materials, shapes, and relative positions of components, are merely examples of embodiments related to the claims, and are not intended to limit the scope of the claims to the configurations disclosed in these examples. Furthermore, the problems solved by the configurations disclosed in the following examples or the actions or effects obtained from the disclosed configurations are not intended to limit the scope of the claims.

[0010] First Embodiment First, an HMD 1, which is a display device according to a first embodiment of the present invention, will be described.

[0011] 1A is a perspective view of the HMD 1. The HMD 1 is composed of an HMD main body 11 and a wearing band 12. The wearing band 12 is an annular member that is fixed to the user's head. The HMD main body 11 is held by the wearing band 12 so as to be positioned in front of the user's eyes.

[0012] 1B is a view of the HMD main body 11 as seen from the user's side. The HMD main body 11 has a pair of display units 13L and 13R inside a main body cover 110, which display images to the user's left and right eyes. The pair of display units 13L and 13R have displays 141L and 141R and movable lenses 142L and 142R, which will be described later, as a pair of optical elements corresponding to the user's left and right eyes. By observing the displays 141L and 141R through the movable lenses 142L and 142R, the user can visually recognize the images displayed on the displays 141L and 141R as virtual images.

[0013] The pair of display units 13L, 13R are configured so that the positions of the pair of optical elements can be displaced in a plurality of predetermined directions relative to the body cover 110 of the HMD body 11. The body cover 110 is fixedly held on the user's head via the wearing band 12. Therefore, the pair of display units 13L, 13R are capable of displacing and adjusting the relative positions of the optical elements with respect to the left and right eyeballs of the user by displacing the positions of the optical elements with respect to the body cover 110.

[0014] The display unit 13L for the left eye and the display unit 13R for the right eye have a bilaterally symmetrical (mirror symmetrical) structure. Each component of the left eye display unit 13L is assigned a reference number with an "L" added to the end, and each component of the right eye display unit 13R is assigned a reference number with an "R" added to the end. In the following description of the display units 13L and 13R, when it is not necessary to distinguish between the left and right, the structure of the left eye display unit 13L will be mainly described, and the "L" in the reference number may be omitted. Note that the reference numbers shown in Figures 2 and 5 omit the "L". Each structure of the right eye display unit 13R is the same as that of the left eye display unit 13L.

[0015] 2A and 2B, the configuration of the display units 13L and 13R of the HMD 1 will be described. 2A and 2B are exploded perspective views of the left-eye display unit 13L, and as described above, the "L" is omitted from the reference numerals shown in the figures.

[0016] The display unit 13 is mainly composed of a plurality of optical elements, a plurality of guide mechanisms, a drive source that generates a drive force to move the optical elements, a holding member that holds the optical elements, and a unit housing. The plurality of optical elements typically include a display 141 and a movable lens 142. Optical elements other than those shown in this embodiment may also be included.

[0017] In this embodiment, the multiple guide mechanisms include a first guide mechanism 151 for guiding the displacement of the display 141 and the movable lens 142 in a first direction D1, and a second guide mechanism 152 for guiding the displacement of the movable lens 142 of the optical element in a second direction D2.

[0018] Here, the first direction D1 is a direction along the alignment direction of a pair of optical elements (e.g., movable lenses 142L and 142R) and is parallel to the horizontal direction in the basic wearing position of the HMD 1. The second direction D2 is a direction along the optical axis of the optical elements and is also parallel to the horizontal direction in the basic wearing position of the HMD 1. The first direction D1 and the second direction D2 are typically perpendicular to each other, but even if the intersecting direction is slightly angled relative to the perpendicular direction, such a configuration can be adopted as a configuration of the present invention if the same effect as in the case of the perpendicular direction can be obtained. Similarly, with regard to the third direction D3 ( FIG. 3 ) that intersects both the first direction D1 and the second direction D2 (described later), in this embodiment, it is a direction perpendicular to both the first direction D1 and the second direction D2, but it may also be an intersecting direction slightly angled relative to the perpendicular direction. Note that in this embodiment, when the second direction D2, which is the optical axis direction, is parallel to the horizontal direction, the third direction D3 is a vertical direction (the direction of gravity, up and down direction).

[0019] Among the optical elements, the movable lens 142 is held by a lens holder 131 serving as a holding member inside a base 132 and a cover 133, which are unit housings. The movable lens 142 is configured to be movable in the second direction D2 as the lens holder 131 moves inside the unit housing in the same direction. The lens holder 131 receives a driving force from a motor 161 serving as a driving source (driving means) and is guided by a second guide mechanism 152, thereby being displaceable in the second direction inside the unit housing (base 132 and cover 133). As the lens holder 131 moves in the optical axis direction, which is the second direction, the movable lens 142 is displaced in the optical axis direction, and the distance between the lens holder 131 and the display 141 in the second direction D2 (the position of the movable lens 142 between the user's eyes and the display 141) changes. In the display unit 13, the optical axis of the optical system formed by the display 141 and the movable lens 142, which are optical elements, is denoted as O1.

[0020] In the following description, the term "substantially parallel" to each direction such as the optical axis direction may be used. This means that not only a direction strictly parallel to each direction but also a direction slightly tilted from each direction can be adopted as a configuration of the present invention (it can be considered the same as a parallel direction) if the same effect as that obtained when the direction is parallel can be obtained.

[0021] Display 141L displays an image for the left eye, and movable lens 142L refracts light rays emitted from display 141L to display an appropriate image in the optical axis direction. Display 141R displays an image for the right eye, and movable lens 142R refracts light rays emitted from display 141R to display an appropriate image in the optical axis direction.

[0022] Display 141, which is the first optical element, is fixed to base 132. Base 132 is held movably in a first direction D1 shown in the figure by a first guide mechanism 151 (main bar 151a, sub-bar 151b). First guide mechanism 151 has main bar 151a, which is an axial member extending in first direction D1 as a first main guide portion, and sub-bar 151b, which is an axial member extending in first direction D1 as a first sub-guide portion.

[0023] The main bar 151a and sub bar 151b, which constitute the first guide mechanism 151, are fixed to the main body cover 110 (see FIG. 1B ) of the HMD main body 11. That is, the main bar 151a and sub bar 151b are fixedly held at predetermined positions relative to the user's head via the main body cover 110 and the wearing band 12. The relative positions of the display units 13L and 13R with respect to the left and right eyeballs of the user can be displaced in the first direction D1 by displacing the positions at which the unit housings (base 132 and cover 133) are held by the main bar 151a and sub bar 151b in the first direction D1.

[0024] The main bar 151a is inserted into the fitting portion 132a of the base 132 in the first direction D1 and holds the base 132 so that it can move linearly in the first direction D1 and rotate around the first direction D1. The fitting portion 132a is a shaped portion of the base 132 having an axial hole through which the main bar 151a is inserted. In this embodiment, two fitting portions 132a are provided at an upper end (one end) of the base 132 in the third direction D3 (see FIG. 3 ), spaced apart in the first direction D1. The sub-bar 151b is inserted into the fitting portion 132b of the base 132 in the first direction D1 and restricts rotation of the base 132 around the first direction D1. The fitting portion 132b is a shaped portion of the base 132 having an axial hole through which the sub-bar 151b is inserted. In this embodiment, one fitting portion 132b is provided at a lower end (the other end) of the base 132 in the third direction D3 (see FIG. 3 ). In the first direction D1, the fitting portion 132b is located between the two fitting portions 132a (see FIG. 3).

[0025] As described above, the first guide mechanism 151 holds the base 132 (lens holder 131) movably in the first direction D1 using the main bar 151a and the sub-bar 151b. That is, the lens holder 131 is displaced in the first direction D1 by the mating position of the mating portion 132a relative to the main bar 151a and the mating position of the mating portion 132b relative to the sub-bar 151b being displaced in the first direction D1. This allows the display 141 fixed to the lens holder 131 and the movable lens 142 supported by the lens holder 131 to be displaceable in the first direction D1.

[0026] In the HMD 1 according to this embodiment, the main bar 151a and the sub-bar 151b are used as a common first guide mechanism that guides both the display unit 13L and the display unit 13R in the first direction D1.

[0027] A movable lens 142, which is a second optical element, is held by a lens holder 131. The lens holder 131 is held by a second guide mechanism 152 (main bar 152a, sub-bar 152b) so as to be movable in the second direction D2 shown in the figure. The second guide mechanism 152 has a main bar 152a, which is an axial member extending in the second direction D2 as a second main guide portion, and a sub-bar 152b, which is an axial member extending in the second direction D2 as a second sub-guide portion. As with the first guide mechanism 151, the main bar 152a is inserted into an axial hole of a fitting portion 131a provided in the lens holder 131, and the sub-bar 152b is inserted into an axial hole of a fitting portion 131b provided in the lens holder 131. One end of the main bar 152a and the sub-bar 152b in the second direction D2 is fixed to the base 132, and the other end is fixed to the cover 133. The main bar 152a and the sub bar 152b are arranged at different positions on a plane perpendicular to the second direction D2, which is the optical axis direction, in order to stabilize the movement of the lens holder 131 in the second direction D2, but this is a characteristic configuration of the HMD1 of this embodiment and will be described in detail later.

[0028] With the above configuration, the second guide mechanism 152 can hold the movable lens 142 and the lens holder 131 movably in the second direction D2 using the main bar 152a and the sub-bar 152b. That is, by displacing the mating position of the mating portion 131a relative to the main bar 152a and the mating position of the mating portion 131b relative to the sub-bar 152b in the second direction D2, the lens holder 131 can be displaced in the second direction D2. This makes it possible to displace the position of the movable lens 142 supported by the lens holder 131 relative to the unit housing (base 132 and cover 133), i.e., the position relative to the user's eye, in the second direction D2.

[0029] The cover 133 is fixed to the base 132 so as to cover the movable lens 142 and the lens holder 131 .

[0030] The unit housing (base 132 and cover 133) of the display unit 13 is positioned in the first direction D1 with respect to the user's head by the main bar 151a and sub-bar 151b of the first guide mechanism. This determines the position of the display 141, which is the first optical element, with respect to the user's head (eye). This also determines the position of the movable lens 142 (lens holder 131), which is the second optical element, with respect to the user's head (eye) in the first direction D1. The position of the movable lens 142 with respect to the user's head (eye) in the second direction D2 is determined by the main bar 152a and sub-bar 152b of the second guide mechanism determining the position of the lens holder 131 with respect to the unit housing (base 132 and cover 133) in the second direction D2.

[0031] The left and right display units 13L, 13R can be moved in a first direction D1 with the guidance of a first guide mechanism 151, thereby changing the distance between the optical elements of the left-eye display unit 13L and the right-eye display unit 13R. Furthermore, the movable lens 142 can be moved in a second direction D2, which is substantially parallel to the optical axis O1, with the guidance of a second guide mechanism 152, thereby changing the focal length of the image viewed by the user. A motor 161 that generates a driving force to move the movable lens 142 in the second direction D2 has a drive shaft (rotation shaft) 161a extending in the second direction D2 and is fixed to the base 132. The drive shaft 161a of the motor 161 has a male threaded portion on its outer periphery, which threads into a female threaded portion of a connecting member 131c provided on the lens holder 131, thereby connecting to the connecting member 131c. The rotational driving force transmitted from the drive shaft 161a of the motor 161 to the female thread portion of the connecting member 131c is converted into a propulsive driving force in the second direction D2 by the guiding action of the second guide mechanism 152, and moves the lens holder 131 in the second direction D2. As a result, the movable lens 142 moves in the second direction D2.

[0032] When adjusting the IPD of the HMD 1, for example, the user looks into the display units 13L and 13R to view the image, and opens and closes the display units 13L and 13R to adjust the spacing between the optical elements to maximize visibility. When adjusting the diopter of the HMD 1, for example, the user operates an operating means (not shown) to drive the motor 161 while viewing the image, thereby displaying the image at a focal length that makes it easy to focus.

[0033] (Features, Actions, and Effects of the HMD 1 of the First Embodiment) Fig. 3A is a view of the display units 13L and 13R of the HMD 1 as viewed in the second direction D2. Fig. 3B is a view of the display unit 13 of the HMD 1 as viewed in the first direction D1. In Fig. 3A, the display unit 13 shows the interior without showing the cover 133, and Fig. 3B is a view showing only the outer shape and main internal structure of the display unit 13.

[0034] In the display unit 13 of this embodiment, a main bar 151a, which is a first main guide portion, and a sub-bar 151b, which is a first sub-guide portion, are arranged above and below the optical axis O1. More specifically, the main bar 151a fits into a fitting portion 132a provided at the upper end of the unit housing (base 132) of the display unit 13 in the third direction D3, which is the up-down direction. Furthermore, the sub-bar 151b fits into a fitting portion 132b provided at the lower end of the unit housing (base 132).

[0035] The main bar 152a, which is the second main guide portion, is disposed outside the two optical axes O1L and O1R in the left-right direction (area A1 in the figure). More specifically, the main bar 152a is disposed on the opposite side of the optical axis O1 from the side where the center of the HMD 1 is located, i.e., on the longitudinal end side of the HMD 1 along the first direction D1, in the first direction D1 along the alignment direction of the pair of optical elements (the pair of display units 13). In this embodiment, the main bar 152a is disposed below the optical axis O1 in the third direction D3, which is the up-down direction, and near the longitudinal end of the HMD 1 in the first direction D1, which is the left-right direction. The motor 161 is also disposed near the longitudinal end of the HMD 1 in the first direction D1, and the main bar 152a and the motor 161 are disposed to have an overlapping area when viewed in the third direction D3, which is the up-down direction.

[0036] The sub-bar 152b, which is the second sub-guide portion, is disposed inside the two optical axes O1L and O1R (between the optical axes O1L and O1R) in the left-right direction. More specifically, the sub-bar 152b is disposed on the side of the optical axis O1 where the center of the HMD 1 is located, in the first direction D1 along the alignment direction of the pair of optical elements (the pair of display units 13). The position of the sub-bar 152b in the first direction D1 is such that the sub-bar 152b has an area overlapping with the movable lens 142 when viewed in the third direction D3. In addition, in this embodiment, the main bar 152a is disposed above the optical axis O1 in the third direction D3, which is the up-down direction, and near the upper end of the HMD 1.

[0037] As shown in FIG. 3B , the length in the second direction D2 of the sub-bar 152b, which serves as the second auxiliary guide portion (L2 in the figure), is shorter than the length in the second direction D2 of the main bar 152a, which serves as the second main guide portion (L1 in the figure). In addition, in the second direction D2, at least one end of the sub-bar 152b is located between the longitudinal ends of the main bar 152a. The sub-bar 152b is offset in the second direction D2, which is the optical axis direction, relative to the first guide mechanism 151 (main bar 151a, sub-bar 151b). In other words, the sub-bar 152b is positioned so that it does not overlap with the first guide mechanism 151 (main bar 151a, sub-bar 151b) when viewed in the third direction D3, which is the up-down direction.

[0038] 3A, when viewed in the second direction D2, sub-bar 152b, which is the second auxiliary guide portion, is positioned closer to first guide mechanism 151 (main bar 151a, sub-bar 151b) than main bar 152a, which is the second main guide portion. In other words, the shortest distance between sub-bar 152b and the guide portion of main bar 151a or sub-bar 151b that is closer to sub-bar 152b is shorter than both the shortest distance between main bar 151a and main bar 152a and the shortest distance between sub-bar 151b and main bar 152a.

[0039] When viewed in the second direction D2, the shorter of the shortest distance between the main bar 152a and the main bar 151a and the shortest distance between the main bar 152a and the sub-bar 151b is defined as distance L3 (first distance). In the present embodiment, this corresponds to the shortest distance between the main bar 152a and the sub-bar 151b. Furthermore, when viewed in the second direction D2, the shorter of the shortest distance between the sub-bar 152b and the main bar 151a and the shortest distance between the sub-bar 152b and the sub-bar 151b is defined as distance L4 (second distance). In the present embodiment, this corresponds to the shortest distance between the sub-bar 152b and the main bar 151a. In the HMD 1 according to the present embodiment, the first guide mechanism 151 (main bar 151a, sub-bar 151b) and the second guide mechanism 152 (main bar 152a, sub-bar 152b) are laid out so that distance L4 is shorter than distance L3.

[0040] When an HMD is equipped with both an IPD adjustment function and a diopter adjustment function, as described above, it is necessary to move the optical element in different directions (first direction D1, second direction D2). When guiding a single moving object in multiple directions using multiple guide mechanisms, a typical mechanical configuration, as in the HMD of this embodiment, is one in which one or more of the multiple guide mechanisms are guided by a separate guide mechanism along with the moving object. In this case, if the multiple guide mechanisms have guide shafts extending in the respective guide directions, a configuration may be adopted in which sufficient spacing is provided between the guide mechanisms to prevent interference between the guide shafts. Such a configuration may result in a larger external size of the display unit, leading to an increase in the size of the device. Furthermore, because the display unit is adjacent to the user's face, depending on the layout of the guide mechanism, a protruding portion may be formed relative to the surface shape of the area around the user's eyes, potentially reducing wearability due to interference with the area around the user's eyes.

[0041] 3A , when the user wears the HMD 1, the display units 13L and 13R are close to the user's face. For example, if a long member is placed in the second direction D2 in an area close to the user's nose or forehead, the display units 13L and 13R may protrude toward the user's face. This protruding portion may interfere with the user's face, potentially reducing the comfort of wearing the HMD 1. If the member is placed deep inside the HMD main body 11 (not shown) to avoid interference with the user, a large amount of free space must be provided deep inside the HMD main body 11 to avoid the interference, which may result in the HMD becoming larger.

[0042] In the HMD 1 of this embodiment, as shown in FIG. 3B , the main bar 152a, which is the second main guide portion of the second guide mechanism 152, and the sub-bar 152b, which is the second sub-guide portion, use bar members with different lengths in the second direction D2. The guide mechanism for the movable lens 142 is required to restrict the tilt of the movable lens 142, for example, as indicated by M1 in FIG. 3B . One method for effectively suppressing the tilt M1 is to increase the length of either the engagement portion 131a (the length of the engagement area with the main bar 152a in the second direction D2) or the engagement portion 131b (the length of the engagement area with the sub-bar 152b in the second direction D2). In this embodiment, the length of the engagement portion 131a is increased while the length of the engagement portion 131b is minimized. As a result, the main bar 152a can be increased in length while the sub-bar 152b can be shortened.

[0043] In order to more effectively suppress tilt of the movable lens 142, the fitting portions 131a and 131b are arranged in the second direction D2 so that they each have a region where they are positioned in the same position in the second direction D2. That is, for example, when a virtual plane including the axis of the axial hole of the fitting portion 131a and the axis of the axial hole of the fitting portion 131b is viewed in a direction perpendicular to the axis, the fitting portions 131a and 131b are arranged so that they have a region where they overlap each other. Alternatively, the fitting portions 131a and 131b are arranged so that at least one end of one of the fitting portions 131a and 131b is located between both ends of the other fitting portion in the second direction D2.

[0044] As mentioned above, placing the main bar 152a long in the second direction D2 in region A2 is undesirable because it may interfere with the user and increase the size of the HMD. Furthermore, the main bar 151a and sub-bar 151b of the first guide mechanism 151 are located above and below the optical axes O1L and O1R, and interference between them must be avoided. In light of this, in the HMD 1 of this embodiment, the main bar 152a long in the second direction D2 is located outside the two optical axes O1L and O1R in the left-right direction and at a position (distant position) far from the main bar 151a and sub-bar 151b. This placement allows the main bar 152a to be adjacent to the movable lens 142 while avoiding interference with the main bar 151a and sub-bar 151b of the first guide mechanism 151. This prevents the display unit 13 from becoming too large and reduces interference with the user's face.

[0045] Furthermore, the sub-bar 152b, which is shorter in the second direction D2, is disposed near the main bar 151a or the sub-bar 151b. In the HMD 1 of this embodiment, the sub-bar 152b is disposed near the main bar 151a. The sub-bar 152b and its peripheral mechanism are configured to be short in the second direction D2 (i.e., have a small thickness in the second direction D2). Therefore, in the HMD 1 of this embodiment, the sub-bar 152b and its peripheral mechanism are disposed so as to overlap (be aligned in the second direction D2) with the main bar 151a and its peripheral mechanism in the second direction D2. Note that in this arrangement, even if the sub-bar 152b moves together with the display unit 13 in the first direction D1, the main bar 152a and its peripheral mechanism do not interfere with the main bar 151a or the sub-bar 151b. This is because the main bar 152a and its peripheral mechanisms are arranged so as not to overlap the main bar 151a and its peripheral mechanisms, and the sub-bar 151b and its peripheral mechanisms when viewed in the first direction D1.

[0046] Here, a comparative example in which the effects of the present invention cannot be obtained, unlike the HMD 1 of this embodiment, will be described in comparison with the configuration of this embodiment.

[0047] As shown in FIG. 3A , in the HMD 1 of this embodiment, the sub-bar 152b and its peripheral mechanism are arranged in region A3. In contrast, as a comparative example in which the effects of the present invention cannot be obtained, a case in which the sub-bar 152b uses a bar member of the same length as the main bar 152a will be described. For example, if the main bar 152a is positioned without changing its position, regions A4 and A5 in FIG. 3A are candidates for arranging the sub-bar 152b and its peripheral mechanism. Region A4 is located at approximately the same height as the optical axis O1 in the third direction D3, which is the up-down direction, and is located away from the first guide mechanism 151 (main bar 151a, sub-bar 151b). Region A5 is located outside the first guide mechanism 151 (main bar 151a, sub-bar 151b) in the third direction D3, which is the up-down direction. If the sub-bar 152b and its peripheral mechanism were arranged in region A4, they would interfere with the user's nose. Furthermore, if the sub-bar 152b and its peripheral mechanisms were arranged in area A5, they would not be able to be placed close enough to the main bar 151a to avoid interference with the main bar 151a, resulting in an increase in the external size of the display unit 13. In contrast to these arrangements, the HMD 1 of this embodiment prevents the display unit 13 from becoming larger and also prevents interference with the user.

[0048] As described above, the HMD 1 of this embodiment can prevent the display device from becoming too large and also prevent interference with the user in a display device having a plurality of visual adjustment mechanisms.

[0049] In the HMD 1 of this embodiment, of the main bar 151a, which is the first main guide portion, and the sub-bar 151b, which is the first sub-guide portion, the main bar 151a is the guide portion closest to the sub-bar 152b, which is the second sub-guide portion, when viewed in the second direction D2. As shown in FIG. 3B , the sub-bar 152b is not positioned so as to straddle the main bar 151a in the second direction D2, but is shifted in the second direction D2 relative to the main bar 151a. In other words, when viewed in the third direction D3, there is no overlapping area between the main bar 151a and the sub-bar 152b. This positioning allows the sub-bar 152b and the main bar 151a to be positioned closer to each other when viewed in the second direction D2, which is preferable because it enables the display unit 13 to be made smaller.

[0050] 3B , in the HMD 1 of this embodiment, the main bar 152a is arranged to straddle the main bar 151a and the sub-bar 151b in the second direction D2. That is, the main bar 151a and the sub-bar 151b are positioned between both ends of the main bar 152a in the second direction D2. This arrangement reduces the effect of the main bar 152a, which is long in the second direction D2, on the size (length) of the HMD 1 in the second direction D2 by at least the length of the main bar 151a and the sub-bar 151b in the second direction D2. This arrangement reduces the amount by which the main bar 152a, which is long in the second direction D2, protrudes toward the user, which is preferable because it minimizes interference with the user.

[0051] In the HMD 1 of this embodiment, the main bar 152a, which is the second main guide portion, is disposed between the main bar 151a, which is the first main guide portion, and the sub-bar 151b, which is the first sub-guide portion, in the third direction D3, which is the up-down direction. As shown in FIG. 3A , in the area A1, which is outside the two optical axes O1L and O1R, the main bar 152a is unlikely to interfere with the user regardless of its position. Furthermore, even within the area A1, it is preferable to dispose the main bar 152a between the main bar 151a and the sub-bar 151b in the third direction D3, which is the up-down direction. This disposition prevents interference between the main bar 152a and the sub-bar 151b even when the main bar 152a and its peripheral mechanisms move in the first direction D1 in conjunction with the movement of the display unit 13. This configuration reduces restrictions on the placement of the main bar 152a in the first direction D1, which is the left-right direction, and allows the main bar 152a to be disposed adjacent to the optical element. This makes it possible to further reduce the size of the display unit 13, which is preferable.

[0052] Furthermore, in the HMD 1 of this embodiment, the sub-bar 152b, which is the second auxiliary guide portion, is positioned inward from both longitudinal ends of the main bar 151a, which is the first main guide portion, in the first direction D1, which is the left-right direction. The main bar 151a is positioned to extend in the first direction D1, farther from the user's face than the movable lens 142, in the second direction D2, which is the optical axis direction. Therefore, the space on the user's face side of the main bar 151a in the second direction D2 is suitable for arranging components that move in the first direction D1. On the other hand, if the sub-bar 152b protrudes from the main bar 151a in the first direction D1, a free space must be secured at the protruding portion to avoid interference, which would result in an increase in the size of the HMD main body 11. Therefore, it is preferable that the sub-bar 152b, which is the second auxiliary guide portion, be positioned inward from both longitudinal ends of the main bar 151a, which is the first main guide portion, in the first direction D1.

[0053] Second Embodiment An HMD 2 according to a second embodiment of the present invention will be described. Note that a repetitive description of matters common to the second embodiment and the first embodiment will be omitted. Matters in the second embodiment that are not particularly described here are the same as those in the first embodiment. Like the HMD 1, the HMD 2 is a display device having two display units 23L and 23R that display images to the left and right eyes of the user. An overview of the HMD 2 will be described using FIG. 4.

[0054] Fig. 4A is a perspective view of an HMD 2 according to the second embodiment. Like the HMD 1, the HMD 2 is composed of an HMD main body 21 and a wearing band 22. Fig. 4B is a view of the HMD main body 21 as seen from the user's side. Like the HMD main body 11 of the HMD 1, the HMD main body 21 has two display units 23L and 23R inside a main body cover 210. The display units 23L and 23R display images to the user's left and right eyes using optical elements (displays 241L and 241R, movable lenses 242L and 242R), respectively.

[0055] The configuration of the display units 23L and 23R of the HMD 2 will be described with reference to Figures 5A and 5B. Figures 5A and 5B are exploded perspective views of the left-eye display unit 23L. The following description will focus on the structure of the left-eye display unit 23L, but since the left-eye display unit 23L and the right-eye display unit 23R have mirror-symmetrical structures, similar to those of the HMD 1, a description of the right-eye display unit 23R will be omitted. The optical axes of the display units 23L and 23R will be represented as O1L and O1R, similar to those of the HMD 1.

[0056] The display unit 23 is mainly composed of a plurality of optical elements, a plurality of guide mechanisms, a drive source that generates a drive force to move the optical elements, a holding member that holds the optical elements, and a unit housing. The plurality of optical elements typically include a display 241 and a movable lens 242. Optical elements other than those shown in this embodiment may also be included.

[0057] The HMD 2 of this embodiment differs from the HMD 1 of embodiment 1 in the configuration of the first guide mechanism 251 and the second guide mechanism 252, and in that it is provided with motors 261 and 262 as drive sources and an eyeball camera 271.

[0058] In this embodiment, the multiple guide mechanisms include a first guide mechanism 251 for guiding displacement of the display 241 and the movable lens 242 in the first direction D1, and a second guide mechanism 252 for guiding displacement of the movable lens 242, which is one of the optical elements, in the second direction D2. The first direction D1 to the third direction D3 described in this embodiment are the same as those in the first embodiment.

[0059] The display 241 and the movable lens 242 are similar to the display 141 and the movable lens 142 of the HMD 1. The display 241 is fixed to a base 232, and the base 232 is held by a first guide mechanism 251 (main bar 251a, sub-bar 251b) so as to be movable in a first direction D1 shown in the figure. The first guide mechanism 251 has a main bar 251a that extends in the first direction D1 as a first main guide portion, and a sub-bar 251b that extends in the first direction D1 as a first sub-guide portion.

[0060] Similar to the HMD 1, the main bar 251a is inserted into the fitting portion 232a of the base 232, and the sub-bar 251b is inserted into the fitting portion 232b of the base 232. The first guide mechanism 251 holds the base 232 (display unit 23) movably in the first direction D1 by the main bar 251a and the sub-bar 251b.

[0061] Unlike the HMD 1, the HMD 2 has display units 23L and 23R each having a first guide mechanism 251L and 251R, respectively.

[0062] Similar to the HMD 1, the movable lens 242 is held by the lens holder 231 and held by a second guide mechanism 252 (main bar 252a, sub-bar 252b) so as to be movable in the second direction D2 shown in the figure. The second guide mechanism 252 has a main bar 252a extending in the second direction D2 as a second main guide portion, and a sub-bar 252b extending in the second direction D2 as a second sub-guide portion. The main bar 252a is inserted into the fitting portion 231a, and the sub-bar 252b is inserted into the fitting portion 231b. This allows the second guide mechanism 252 to hold the movable lens 242 and the lens holder 231 so as to be movable in the second direction D2 using the main bar 252a and sub-bar 252b. The description of the cover 233 is the same as that of the HMD 1.

[0063] Eyeball camera 271 is held by base 232 and observes the user's eyeballs. From the results of eyeball observation, the position of the eyeballs, the line of sight direction, and the user's gaze point can be calculated.

[0064] The motor 261 is held by the HMD main body 21 (not shown), and a drive shaft 261a of the motor 261 is threadedly engaged with and connected to a connecting member 232c provided on the base 232. By rotating the drive shaft 261a, the two display units 23L and 23R are driven in a first direction D1, making it possible to change the distance between the optical element of the left eye display unit 23L and the optical element of the right eye display unit 23R.

[0065] The motor 262 is held by the cover 233, and a drive shaft 262a of the motor 262 is threadedly engaged with and connected to a connecting member 231c provided on the lens holder 231. Rotating the drive shaft 262a drives the optical element (movable lens 242) in the second direction D2. By moving the movable lens 242 in the second direction D2, it is possible to change the focal length of the image seen by the user.

[0066] When adjusting the IPD in the HMD 2, for example, the HMD main body 21 can drive the motor 261 to automatically adjust the spacing between the optical elements in accordance with the spacing between the left and right eyes observed by the eyeball camera 271. This can improve the visibility of the image without relying on user operation.

[0067] Furthermore, in a typical HMD, a state in which the depth of an object the user is gazing at differs from the focal length of the image is called a convergence accommodation conflict. Convergence accommodation conflict can reduce the visibility of nearby objects and cause motion sickness. In the HMD 2, for example, the object the user is gazing at is detected from an image captured by the eyeball camera 271, and the HMD main body 21 drives the motor 262 to adjust the focal length of the image according to the detected depth. This resolves the convergence accommodation conflict, which is expected to improve the visibility of nearby objects and reduce motion sickness.

[0068] (Features, Actions, and Effects of the HMD 2 of the Second Embodiment) Fig. 6A is a view of the display units 23L and 23R of the HMD 2 as viewed in the second direction D2. Fig. 6B is a view of the display unit 23 of the HMD 2 as viewed in the first direction D1. In Fig. 6A, the display unit 23 shows the interior without showing the cover 233, and Fig. 6B is a view showing only the outer shape and main internal structure of the display unit 23.

[0069] In the display unit 23 of this embodiment, the main bar 251a, which is the first main guide portion, and the sub-bar 251b, which is the first sub-guide portion, are arranged above and below the optical axis O1 in the third direction D3. The main bar 252a, which is the second main guide portion, is arranged outside (area A1 in the figure) the two optical axes (optical axis O1L, optical axis O1R) in the first direction D1, which is the left-right direction.

[0070] Also, as shown in Figure 6B, the length in the second direction D2 of the sub-bar 252b, which is the second auxiliary guide portion (L2 in the figure), is shorter than the length in the second direction D2 of the main bar 252a, which is the second main guide portion (L1 in the figure).

[0071] 6A, when viewed in the second direction D2, sub-bar 252b, which is the second auxiliary guide portion, is positioned closer to first guide mechanism 251 (main bar 251a, sub-bar 251b) than main bar 252a, which is the second main guide portion. In other words, the shortest distance between sub-bar 252b and the guide portion of main bar 251a or sub-bar 251b that is closer to sub-bar 252b is shorter than both the shortest distance between main bar 251a and main bar 252a and the shortest distance between sub-bar 251b and main bar 252a.

[0072] When viewed in the second direction D2, the shorter of the shortest distance between the main bar 252a and the main bar 251a and the shortest distance between the main bar 252a and the sub-bar 251b is defined as distance L3 (first distance). In the present embodiment, this corresponds to the shortest distance between the main bar 252a and the sub-bar 251b. Furthermore, when viewed in the second direction D2, the shorter of the shortest distance between the sub-bar 252b and the main bar 251a and the shortest distance between the sub-bar 252b and the sub-bar 251b is defined as distance L4 (second distance). In the present embodiment, this corresponds to the shortest distance between the sub-bar 252b and the main bar 251a. In the HMD 2 according to the present embodiment, the first guide mechanism 251 (main bar 251a, sub-bar 251b) and the second guide mechanism 252 (main bar 252a, sub-bar 252b) are laid out so that distance L4 is shorter than distance L3.

[0073] In the HMD 2, when viewed in the second direction D2, the sub-bar 252b has an area that overlaps with the main bar 251a, and the distance L4 is zero.

[0074] As shown in FIG. 6B , the length (L5 in the figure) of the motor 262, which is the driving means, in the second direction D2 is shorter than the length (L1 in the figure) of the main bar 252a, which is the second main guide portion. Furthermore, as shown in FIG. 6A , when viewed in the second direction D2, the shorter of the shortest distance between the motor 262 and the main bar 251a and the shortest distance between the motor 262 and the sub-bar 251b is defined as distance L6 (third distance). In this embodiment, this corresponds to the shortest distance between the motor 262 and the sub-bar 251b. The HMD 2 according to this embodiment is configured so that distance L6 is shorter than the first distance L3. In the HMD 2, when viewed in the second direction D2, the motor 262 has an overlapping area with the sub-bar 251b, and distance L6 is zero.

[0075] As described in the explanation of HMD 1, when both the IPD adjustment function and the diopter adjustment function are installed, it is necessary to arrange the multiple guide mechanisms extending in two directions without interfering with each other. Furthermore, the area indicated by area A2 in Figure 6(a) is close to the nose and forehead, and if a long member is arranged in area A2 in the second direction D2, it may protrude toward the user and interfere with the user. Avoiding this would result in an increased size of the HMD.

[0076] In the HMD 2 of this embodiment, similar to the HMD 1 of the first embodiment, the length in the second direction D2 differs between the main bar 252a, which is the second main guide portion of the second guide mechanism 252, and the sub-bar 252b, which is the second sub-guide portion.

[0077] In the HMD2 of this embodiment, the main bar 252a, which is long in the second direction D2, is disposed outside the two optical axes O1L and O1R in the first direction D1, which is the left-right direction, and at a position (distant position) away from the main bar 251a and sub-bar 251b. This arrangement allows the main bar 252a to be adjacent to the movable lens 242 while avoiding interference with the main bar 251a and sub-bar 251b, which are the first guide mechanism 251, just like the HMD1. This prevents the display unit 23 from becoming too large and also reduces interference with the user.

[0078] Furthermore, the sub-bar 252b, which is shorter in the second direction D2, is disposed near the main bar 251a or the sub-bar 251b. In the HMD 2 of this embodiment, the sub-bar 252b is disposed near the main bar 251a. With this arrangement, similar to the HMD 1, the sub-bar 252b and its peripheral mechanisms can be disposed so as to overlap (be aligned in the second direction D2) with the main bar 251a and its peripheral mechanisms in the second direction D2.

[0079] Furthermore, in the HMD 2 of this embodiment, the length L5 in the second direction D2 of the motor 262, which is a driving means for driving the optical element (movable lens 242) in the second direction D2, is shorter than the length in the second direction D2 of the motor 161 of the HMD 1. With this configuration, as shown in Fig. 6B, the motor 262 can be arranged so as to overlap (be aligned in the second direction D2) with the sub-bar 251b and its peripheral mechanisms in the second direction D2. This further prevents the display unit 23 from becoming larger.

[0080] With the above-described configuration, the HMD 2, like the HMD 1, can prevent the display device from becoming too large and also prevent interference with the user in a display device having multiple visual adjustment mechanisms.

[0081] In the HMD1, the main bar 151a and sub-bar 151b are common to the display units 13L and 13R, and have the same length in the first direction D1. In contrast, in the HMD2, the display units 23L and 23R each have a main bar 251a and sub-bar 251b. The main bar 251a and sub-bar 251b have different lengths, with a shorter sub-bar 251b being used. Using a shorter sub-bar 251b allows for more space in area A2, further reducing interference with the user. Furthermore, using a shorter sub-bar 251b makes it easier to increase the distance from the main bar 252a. This further enhances the effects of the present invention.

[0082] Furthermore, in the up-down direction (third direction D3), the main bar 251a and the sub-bar 252b are arranged on the same side of the optical axis O1 (above the optical axis O1 in the HMD2). Furthermore, in the up-down direction, the sub-bar 251b and the main bar 252a are arranged on the same side of the optical axis O1 (below the optical axis O1 in the HMD2). Because the main bar 251a is long in the first direction D1, the sub-bar 252b can be arranged close to the main bar 251a even when the display unit 23 is moved in the first direction D1. On the other hand, because the sub-bar 251b is short in the first direction D1, the main bar 252a can be arranged far from the sub-bar 251b even when the display unit 23 is moved in the first direction D1.

[0083] Furthermore, the main bar 251a and the sub-bar 252b are arranged above the optical axis O1 in the vertical direction (third direction D3), and the short sub-bar 251b is arranged in the first direction D1 below the optical axis O1, where the user's nose is most likely to interfere. This makes it possible to further reduce interference with the user, thereby achieving greater benefits of the present invention.

[0084] As with HMD 1, it is preferable that the second sub-guide section not be positioned across the second direction D2 (but be aligned with the second direction D2) for the guide section of the first main guide section and the first sub-guide section that is closest to the second sub-guide section when viewed in the optical axis direction (second direction D2).

[0085] Also, as with HMD 1, it is preferable to position the main bar 252a, which is the second main guide part, so that it straddles the first guide mechanism (main bar 251a, sub-bar 251b) in the optical axis direction (second direction D2).

[0086] Also, as with HMD 1, it is preferable to position the main bar 252a, which is the second main guide part, between the main bar 251a, which is the first main guide part, and the sub-bar 251b, which is the first sub-guide part, in the vertical direction (third direction D3).

[0087] Also, as with HMD 1, it is preferable to position the sub-bar 252b, which is the second auxiliary guide portion, inside both longitudinal ends of the main bar 251a, which is the first main guide portion, in the left-right direction (first direction D1).

[0088] The above-described embodiments can be combined with each other in any possible manner.

[0089] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present disclosure. Therefore, the following claims are appended to clarify the scope of the present disclosure. This application claims priority based on Japanese Patent Application No. 2024-098766, filed June 19, 2024, the entire contents of which are incorporated herein by reference.

[0090] DESCRIPTION OF SYMBOLS 1...HMD, 11...HMD main body, 13L, 13R...display unit, 141L, 141R...display, 142L, 142R...movable lens, O1L, O1R...optical axis, 151, 251...first guide mechanism, 151a, 251a...main bar, 151b, 251b...sub bar, 152, 252...second guide mechanism, 152a, 252a...main bar, 152b, 252b...sub bar, 161, 261, 262...motor

Claims

1. A display device having a pair of display units that display images to left and right eyes, respectively, wherein the pair of display units have: a pair of optical elements arranged corresponding to the left and right eyeballs; a first guide mechanism that holds the pair of optical elements so as to change the spacing between the pair of optical elements in a first direction that is the alignment direction of the pair of optical elements; and a second guide mechanism that holds the pair of optical elements so as to change the positions of the pair of optical elements in a second direction that is the optical axis direction of the optical elements, wherein the first guide mechanism has a first main guide portion and a first sub-guide portion that extend in the first direction, and the second guide mechanism has a second main guide portion and a second sub-guide portion that extend in the second direction, the first main guide portion is located on one side of the optical axis of the optical element in a third direction that intersects both the first direction and the second direction, the first sub-guide portion is located on the other side of the third direction with respect to the optical axis, and the second main guide portion is located outside the optical axis in the first direction, a length in the second direction of the second sub-guide portion is shorter than a length in the second direction of the second main guide portion; and when viewed in the second direction, the shortest distance between the first main guide portion and a guide portion of the first sub-guide portion that is closer to the second sub-guide portion and the second sub-guide portion is shorter than both the shortest distance between the first main guide portion and the second main guide portion and the shortest distance between the first sub-guide portion and the second main guide portion.

2. The display device of claim 1, wherein when viewed in the third direction, the second sub-guide portion does not have an overlapping area with the guide portion of the first main guide portion and the first sub-guide portion that is closer to the second sub-guide portion when viewed in the second direction.

3. The display device according to claim 1, wherein, when viewed in the third direction, the second main guide portion has an area that overlaps with both the first main guide portion and the first sub-guide portion.

4. The display device according to claim 1, wherein, when viewed in the third direction, the second sub-guide portion does not have an overlapping area with either the first main guide portion or the first sub-guide portion.

5. The display device according to claim 1, wherein at least one end of the second auxiliary guide portion is located between both ends of the second main guide portion in the second direction.

6. The display device according to claim 1, wherein the guide portion that is closest to the second sub-guide portion when viewed in the second direction out of the first main guide portion and the first sub-guide portion is the first main guide portion.

7. The display device according to claim 1, wherein the second sub-guide portion is located between the pair of optical axes of the pair of optical elements in the first direction.

8. The display device according to claim 1, wherein the second sub-guide portion has an area that overlaps with the optical element when viewed in the third direction.

9. The display device according to claim 1, wherein the second main guide portion is located between the first main guide portion and the first sub-guide portion in the third direction.

10. A display device as described in claim 1, wherein, when viewed in the second direction, the second sub-guide portion has an overlapping area with the first main guide portion and the guide portion of the first sub-guide portion that is closer to the second sub-guide portion.

11. The display device according to claim 1, wherein the second sub-guide portion is located between the first main guide portion and the first sub-guide portion in the third direction.

12. A display device as described in claim 1, further comprising: a driving means for generating a driving force for moving the optical element in the second direction; the length of the driving means in the second direction is shorter than the length of the first main guide portion in the second direction; and when viewed in the second direction, the shortest distance between the driving means and one of the first main guide portion and the first sub-guide portion that is closest to the driving means is shorter than both the shortest distance between the first main guide portion and the second main guide portion and the shortest distance between the first sub-guide portion and the second main guide portion.

13. The display device according to claim 12, wherein the driving means includes a motor having a rotation axis extending in the second direction.

14. The display device according to claim 12, wherein the driving means has an area that overlaps with the second main guide portion when viewed in the third direction.

15. The display device of claim 1, wherein the length of the first auxiliary guide portion in the first direction is shorter than the length of the first main guide portion in the first direction, and the first main guide portion and the second auxiliary guide portion are located on the same side in the third direction with respect to the optical axis.

16. The display device of claim 1, wherein the length of the first sub-guide portion in the first direction is shorter than the length of the first main guide portion in the first direction, and the first sub-guide portion and the second main guide portion are located on the same side in the third direction with respect to the optical axis.

17. The display device of claim 1, wherein the first main guide portion and the second sub-guide portion are positioned above the optical axis in the third direction, and the first sub-guide portion and the second main guide portion are positioned below the optical axis in the third direction.

18. The display device according to claim 1, wherein the second sub-guide portion is located between both ends of the first main guide portion in the first direction.

19. The display device of claim 1, wherein the pair of display units have: a pair of housings; and a pair of holding members that hold the pair of optical elements inside the pair of housings; the first guide mechanism is capable of changing the spacing between the pair of optical elements in the first direction by changing the spacing between the pair of housings in the first direction; and the second guide mechanism is capable of changing the positions of the pair of holding members inside the pair of housings in the second direction by changing the positions of the pair of optical elements in the second direction.

Images