Display device having pair of display units presenting images to left eye and right eye

Abstract

The present disclosure relates to a display device having a pair of display units presenting images to left and right eyes. Each of the pair of display units includes a lens. The lens includes a first avoidance portion, a second avoidance portion, and a third avoidance portion disposed at different positions in an outer edge when viewed in an optical axis direction. The lens has a shape substantially mirror-symmetric with respect to an imaginary plane passing through the point on the first avoidance portion and the optical axis.

Description

Technical Field

[0001] The present disclosure relates to a display device that presents an image to a user via optical elements, such as a head-mounted display (hereinafter HMD). Background Art

[0002] Mainstream HMDs are constructed with two display units that present images to the user's left and right eyes. Each display unit includes a display that displays images and optical elements, such as lenses, that form images from the display. Each display unit uses these optical elements to present images to the user. In particular, the optical elements of the lenses are manufactured by cutting or forming them using high-precision molds. To reduce costs, it is preferable to use optical elements that are shared between the left and right display units.

[0003] Various components are arranged around the optical elements inside and outside the HMD. For example, outside the HMD, the user's nose is located between the left and right display units. Inside the HMD, a visual adjustment device for adjusting the user's image visibility and a monitoring device for monitoring the user are arranged around the optical elements. In order to avoid interference between the nose and the display units while ensuring a sufficient viewing angle of the optical elements for the user to see the images, a avoidance portion such as a notch is usually provided on the optical elements at a position facing the user's nose. The display device described in Japanese Patent Application Laid-Open No. 2009-036835 shows an example of providing an avoidance portion on the optical elements to avoid interfering with the user's nose. Simply positioning the visual adjustment device and the monitoring device around the optical elements will result in an increase in the size of the display unit. Therefore, a method to avoid an increase in the size of the display unit is to provide other avoidance portions in the optical elements and position the visual adjustment device and the monitoring device at the other avoidance portions.

[0004] However, attempting to use an optical element shared between left and right display units each having multiple keep-out portions may result in an unnecessary loss of viewing angle of the optical element. Summary of the Invention

[0005] An object of the present disclosure is to provide a technology that makes it possible to miniaturize and reduce the cost of a pair of left and right display units in a display device while maintaining a sufficient viewing angle.

[0006] In order to achieve the above-mentioned object, the display device of the present disclosure includes:

[0007] a pair of display units configured to present images to a left eye and a right eye, each of the pair of display units including an optical element,

[0008] Wherein, the optical element includes

[0009] The first avoidance portion, the second avoidance portion, and the third avoidance portion are arranged at different positions of the outer edge of the optical element when viewed along the optical axis, and have

[0010] A shape that is substantially mirror-symmetrical with respect to an imaginary plane passing through a point on the first avoidance portion and the optical axis.

[0011] The present disclosure makes it possible to miniaturize and reduce the cost of a pair of left and right display units in a display device while maintaining a sufficient viewing angle.

[0012] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A and Figure 1B is an external view of the HMD 1 as the first embodiment;

[0014] Figure 2A and Figure 2B is a diagram illustrating a structure of a display unit in an HMD 1 according to one or more aspects of the present disclosure;

[0015] Figure 3A and Figure 3B is a diagram illustrating features and effects of the HMD 1 according to one or more aspects of the present disclosure;

[0016] Figure 4A and Figure 4B is an external view of an HMD 2 according to one or more aspects of the present disclosure;

[0017] Figure 5A and Figure 5B is a diagram illustrating a structure of a display unit in an HMD 2 according to one or more aspects of the present disclosure;

[0018] Figure 6A and Figure 6B is a diagram illustrating features and effects of the HMD 2 according to one or more aspects of the present disclosure; and

[0019] Figure 7A and Figure 7B It is a diagram illustrating an HMD having a comparative design. DETAILED DESCRIPTION

[0020] The embodiments of the present disclosure will be described illustratively with reference to examples. It should be noted that the configurations disclosed in the following examples (e.g., the functions, materials, shapes, and relative configurations of components) are examples of forms associated with the claims and are not intended to limit the scope of the claims to the configurations disclosed in these examples. The problems solved by the configurations disclosed in the following examples or the effects or advantages achieved by the disclosed configurations are not intended to limit the scope of the claims.

[0021] First embodiment

[0022] First, an HMD 1 as a display device according to a first embodiment of the present disclosure is described.

[0023] Figure 1A 1 is a perspective view of an HMD 1. The HMD 1 is composed of an HMD main body 11 and an attachment strap 12. The attachment strap 12 is a headband portion that is firmly attached to the user's head. The HMD main body 11 is held by the attachment strap 12 so as to be positioned in front of the user's eyes.

[0024] Figure 1B This figure shows the HMD body 11 as viewed from the user. The HMD body 11 includes a pair of display units 13L and 13R that present images to the user's left and right eyes. The display units 13L and 13R include displays 141L and 141R, respectively, as well as lenses 142L and 142R and cover glasses 143L and 143R, which are optical elements described later. The user can visually perceive the images displayed on the displays 141L and 141R by observing the displays 141L and 141R through the lenses 142L and 142R and the cover glasses 143L and 143R.

[0025] The left-eye display unit 13L and the right-eye display unit 13R are constructed to be mirror-symmetrical about a vertical axis. Components in the left-eye display unit 13L and the right-eye display unit 13R are given reference numerals with "L" and "R" added at the end, respectively. In the following description of the display units 13L and 13R, when there is no need to distinguish between the left and right display units, the structure of the display units will be mainly described with respect to the left-eye display unit 13L, and the letter "L" may be omitted in the description. Figure 2A and Figure 2B as well as Figure 5A and Figure 5B The reference numerals shown in FIG. 1 do not have “L.” Various structures of the right-eye display unit 13R are the same as those of the left-eye display unit 13L.

[0026] refer to Figure 2A and 2B The structures of the display units 13L and 13R of the HMD 1 are described. Figure 2A and Figure 2B 13L is an exploded perspective view of the left-eye display unit 13L. As described above, the letter "L" is omitted from the reference numerals in the drawings.

[0027] The display unit 13 is mainly composed of a display 141, a lens 142, a cover glass 143, a display base 131, a cover 132, a lens holder 133, a guide rod 134, a motor 135 and a connecting member 136. In the display unit 13, the central axis of the display 141 and the central axis of the optical system formed by optical elements such as the lens 142 and the cover glass 143 are represented by O1 and are called the optical axis. If each optical element has an optical center, the optical axis can be defined as a line passing through these centers. In the following description, a direction may be described as "substantially parallel to" the optical axis. This does not mean that the direction must be exactly parallel to the optical axis. This expression is intended to mean that if a component that is slightly tilted to the optical axis can provide an effect similar to that of a parallel component, such a component may also be adopted as part of the present disclosure (can be considered to be the same as parallel).

[0028] The display 141 in the display unit 13 presents an image to the left eye and is fixed to the display base 131. The lens 142 is, for example, a convex lens and is fixed to the lens holder 133. The lens holder 133 is held by two guide rods 134 extending through the lens holder along the optical axis O1 and is held movable in a direction substantially parallel to the optical axis O1. The two ends of the two guide rods 134 are held by the display base 131 and the cover 132. The motor 135 has a guide shaft 135a and is fixed to the display base 131. The cover glass 143 is fixed to the cover 132. The display base 131 and the cover 132 together constitute the exterior of the display unit 13. The lens holder 133 holds a coupling member 136 that engages with a thread on the guide shaft 135a of the motor 135. When the guide shaft 135a is rotated by the motor 135, the lens holder 133 and the lens 142 move, via the coupling member 136, in a direction substantially parallel to the optical axis O1. As described above, the driver composed of the motor 135, the coupling member 136, and the guide rod 134 moves the lens 142, which is an optical element in the display unit 13, in a direction substantially parallel to the optical axis O1. This movement provides visual accommodation effects such as changes in the focus of an image viewed by the user.

[0029] HMD1 has a reference Figure 3A The following features are described. Figure 3A The left and right display units 13L and 13R are shown as viewed from the user along the optical axes O1L and O1R. Since this is an illustration of the internal structure, the outer contours of the display units 13L and 13R (display bases 131L and 131R and covers 132L and 132R) are shown using dotted lines, and the cover glasses 143L and 143R are not shown. The following description of the left-eye display unit 13L also applies to the right-eye display unit 13R.

[0030] In the HMD 1 of this embodiment, the lens 142, serving as an optical element in the display unit 13, includes a first avoidance portion 142a, a second avoidance portion 142b, and a third avoidance portion 142c in its outer contour. In this embodiment, the first avoidance portion 142a, the second avoidance portion 142b, and the third avoidance portion 142c are notches provided in the circular lens. In this embodiment, the term avoidance portion refers to a feature in the outer contour of an optical element where the distance from the optical axis is locally reduced. Specifically, a avoidance portion refers to a recessed region in the outer shape of the optical element (lens) when viewed along the optical axis, the recessed region appearing as a portion recessed toward the optical axis from the outermost portion substantially along an arc of an imaginary circle surrounding the optical axis. When viewed along the optical axis O1, the first avoidance portion 142a through the third avoidance portion 142c in this embodiment are formed as linear notches in the outer edge of the lens 142. The term linear is used here to describe the shape of each avoidance portion simply because it refers to the (two-dimensional) shape when viewed along the optical axis. Obviously, because lens 142 has thickness in the optical axis direction, each avoidance portion has a flat surface when illustrated in three dimensions. For example, the distance L11 between the outer contour and optical axis O1 in first avoidance portion 142a is shorter than the distances L12 and L13 between the outer contour and optical axis O1 in adjacent portions. Similarly, the distance between the outer contour and optical axis O1 in second avoidance portion 142b and third avoidance portion 142c is shorter than the distance between the outer contour and optical axis O1 in adjacent portions.

[0031] In the present embodiment, the second avoidance portion 142b and the third avoidance portion 142c are substantially mirror-symmetrical about a plane P1 passing through the center of the first avoidance portion 142a and the optical axis O1. Here, plane P1 is an imaginary plane (a second imaginary plane) passing through the optical axis and the center of the outline of the first avoidance portion 142a in the outline of the lens 142 when viewed along the optical axis of the display unit 13. The phrase "substantially mirror-symmetrical" does not mean that the applicable parts must be strictly mirror-symmetrical. This statement is intended to mean that if a part that is not strictly mirror-symmetrical due to a slight difference can provide an effect similar to that of a strictly mirror-symmetrical part, such a part may also be adopted in the applicable configuration of the present disclosure.

[0032] In this embodiment, first avoidance portion 142a is positioned on the outer edge of lens 142, below lens 142 as indicated by direction D1, and on the side closer to the other display unit (display unit 13R) as indicated by direction D2, when viewed along the optical axis. This avoidance portion is a nose avoidance portion configured to avoid interference with the nose of a user wearing HMD 1. Second avoidance portion 142b is positioned on the outer edge of lens 142, below lens 142, and on the side opposite to the side where the pair of lenses 142L and 142R face each other as viewed along the optical axis. In this position, second avoidance portion 142b is adjacent to a driver (motor 135, guide rod 134, and coupling member 136) for driving lens 142 in a direction substantially parallel to optical axis O1. This avoidance portion is a driver avoidance portion configured to avoid interference with the driver when the driver needs to be positioned close to optical axis O1 to miniaturize display unit 13. The third avoiding portion 142 c is positioned on the upper side of the lens 142 in the outer edge of the lens 142 when viewed in the optical axis direction.

[0033] In the two display units 13L and 13R, the lenses 142L and 142R having these avoidance portions are positioned substantially mirror-symmetrically about a plane P2 perpendicular to the left-right direction. Plane P2 is an imaginary plane (a first imaginary plane) extending in a direction perpendicular to the arrangement direction of the pair of lenses 142L and 142R. Plane P2 can also be referred to as an imaginary plane substantially parallel to the optical axis direction of each of the pair of display units 13L and 13R.

[0034] The effects provided by this embodiment as compared with a comparative design will now be described.

[0035] refer to Figure 7A The structure of an HMD as a display device having a comparative design will be described. Figure 7A 93L and the right display unit 93R in the HMD having a comparative design when viewed by a user in the direction of the optical axis O9L of the display unit 93L and the optical axis O9R of the display unit 93R. Since this is an explanation of the internal structure of the display units 93L and 93R, Figure 7ATheir outer contours are shown using dotted lines in FIG. Although not shown, the HMD with a comparative design is identical in overall construction to HMD1, consisting of an HMD main body and an attachment strap. The HMD main body with a comparative design is a display device having two display units 93L and 93R. The comparative HMD is capable of changing the focal length of an image viewed by a user by driving lenses 942L and 942R, which serve as optical elements, along the directions of optical axes O9L and O9R in the display units 93L and 93R. These and other configurations similar to those of HMD1 will not be described in detail. The lens holder 933 and the driver (guide rod 934, motor 935, and coupling member 936) have the same configuration as that of HMD1, and description of these parts will be omitted.

[0036] The left-eye display unit 93L and the right-eye display unit 93R are constructed to be mirror-symmetrical about a vertical axis. In the following description of the display units 93L and 93R, when there is no need to distinguish between the left and right display units, the structure of the display units will be primarily described with respect to the left-eye display unit 93L, and the letter "L" may be omitted from the description. Various structures of the right-eye display unit 93R are similar to those of the left-eye display unit 93L.

[0037] Lens 942 includes a first avoidance portion 942a and a second avoidance portion 942b. The first avoidance portion 942a is a nose avoidance portion configured to avoid interference with the user's nose, and the second avoidance portion 942b is a driver avoidance portion configured to avoid interference with the driver. The second avoidance portion 942b allows the driver to be positioned close to the optical axis O9, thereby reducing the size of the display unit 93. The lens 942 has a symmetrical first avoidance portion 942a and a second avoidance portion 942b. That is, if the lens 942 is shifted or rotated about the optical axis O9, the left-eye lens 942L will be aligned with the right-eye lens 942R. Therefore, the same lens can be used for both lenses 942L and 942R, which helps reduce costs.

[0038] On the other hand, symmetrical positioning of first and second avoidance portions 942a, 942b leads to some problems. For example, in some cases, even if second avoidance portion 942b is smaller than first avoidance portion 942a, the display unit 93 can be accommodated within the HMD body (not shown). In this case, second avoidance portion 942b still needs to be cut to the same size as first avoidance portion 942aL in order to make lens 942 symmetrical. This results in an unnecessary reduction in the viewing angle of the image viewed by the user.

[0039] Figure 7BThis diagram illustrates the viewing angles of the image a user sees in the left-eye display unit 93L. A91 represents the viewing angle area of ​​the image visible to the user. A92 represents the viewing angle area lost due to the provision of the second avoidance portion 942b. A93 represents the viewing angle area that would be lost if the second avoidance portion 942b were only cut to the minimum necessary. The area indicated by A94 represents the unnecessary loss of viewing angle caused by designing both the left lens 942L and the right lens 942R identically.

[0040] Will refer to Figure 3A and Figure 3B The advantageous effects of this embodiment will be described.

[0041] like Figure 3A As shown, in the HMD 1 of this embodiment, the first avoidance portion 142a is positioned below the lens 142 and on the side closest to the other display unit. This avoidance portion is a nose avoidance portion designed to avoid interference with the user's nose. The second avoidance portion 142b is located adjacent to the driver, that is, it is a driver avoidance portion designed to avoid interference with the driver. In the HMD 1, instead of symmetrically forming the first and second avoidance portions 142a, 142b, the second and third avoidance portions 142b, 142c are symmetrically formed about plane P1. This structure allows the first and second avoidance portions 142a, 142b to have different notch shapes while maintaining the same shape for the left and right lenses 142L, 142R. In the HMD 1, if the lens 142L is displaced or rotated about the optical axis O1, it will align with the lens 142R, and vice versa. Therefore, even when a larger cutout of the first avoidance portion 142a is required, the second avoidance portion 142b can be maintained at the minimum necessary cutout shape.

[0042] Figure 3B 142b is a diagram illustrating the viewing angles of the image viewed by the user on the left-eye display unit 13L. A11 represents the viewing angle area of ​​the image visible to the user. A12 represents the viewing angle area lost due to the provision of the second avoidance portion 142b. A13 represents the viewing angle area lost due to the provision of the third avoidance portion 142c.

[0043] Now let's compare Figure 3B The viewing angle of the HMD 1 shown is the same as Figure 7B The viewing angle of the HMD 9 with a comparative design is shown. By forming the second avoidance portion 142b as the driver avoidance portion into the minimum necessary gap, the viewing angle loss can be reduced from Figure 7B The area A92 in the Figure 3B Area A12 in. Figure 3BA13 in FIG. 1 represents the area lost due to the provision of third avoidance portion 142c. Even so, the lost viewing angle (area A13 and area A12 combined) is reduced. Furthermore, as will be described later, the driver and eye camera can be positioned adjacent to third avoidance portion 142c to accommodate various configurations within the space provided by the avoidance portion, which helps make display unit 13 even smaller.

[0044] As described above, the HMD 1 of this embodiment includes the second avoidance portion 142b as a driver avoidance portion, which helps to make the display unit 13 smaller and allows the same lens to be used as the left lens 142L and the right lens 142R, thereby reducing costs. In other words, the HMD 1 of this embodiment can prevent unnecessary narrowing of the viewing angle (which is a problem in HMDs with comparable designs) while allowing the display unit 13 to be miniaturized and reduced in cost.

[0045] In the aforementioned HMD 1, the second avoidance portion 142b, rather than the third avoidance portion 142c, is positioned adjacent to the actuator that drives the lens 142, serving as an optical element, in a direction substantially parallel to the optical axis O1. Configurations that can provide the effects of the present disclosure are not limited to this example. For example, the third avoidance portion 142c, rather than the second avoidance portion 142b, can be positioned adjacent to the actuator. The second avoidance portion 142b or the third avoidance portion 142c can be positioned adjacent to a component other than the actuator that drives the optical element along the optical axis O1. For example, as in the later-described HMD 2, the second avoidance portion 142b can be positioned adjacent to an actuator that drives the optical element in other directions, or adjacent to an eye camera that monitors the user's eyes. The effects of the present disclosure can be achieved by positioning these actuators and eye camera near the avoidance portion. These components do not need to be positioned outside the outer contour of the optical element.

[0046] In the HMD 1 described above, the first avoidance portion 142a, which serves as a nose avoidance portion, is positioned below the lens 142 and on the side close to the other display unit. However, the first avoidance portion 142a does not necessarily need to be formed as a nose avoidance portion. For example, if the driver avoidance portion needs to be a notch larger than the nose avoidance portion, positioning the first avoidance portion 142a adjacent to the driver is more beneficial in terms of miniaturization of the display unit 13 and preventing loss of viewing angle.

[0047] While the avoidance portion of lens 142 in the aforementioned HMD 1 is a notch in a circular lens, the avoidance portion need not be a notch to achieve the effects of the present disclosure. As described above, the term avoidance portion herein refers to a feature in the outer contour of an optical element where the distance from the optical axis O1 is locally reduced. For example, if the optical element has a non-circular outer shape, as in the later-described HMD 2, and does not have a clearly defined notch, the effects of the present disclosure can be achieved if the shape includes a portion where the distance from the optical axis O1 is locally reduced.

[0048] While the second and third avoidance portions 142b and 142c are mirror-symmetrical in the lens 142 of the HMD 1 described above, the configuration is not limited to this example. The effects of the present disclosure can be achieved even if these avoidance portions are not completely mirror-symmetrical, as long as optical performance is not significantly compromised and the actuator or eye camera adjacent to the avoidance portion is not adversely affected.

[0049] In the HMD 1 described above, the lens 142 is provided with three avoidance portions: a first avoidance portion 142a, a second avoidance portion 142b, and a third avoidance portion 142c. These avoidance portions are provided at different positions along the outer edge of the lens 142 when viewed along the optical axis of the display unit 13. In the left display unit 13L and the right display unit 13R, the lenses 142L and 142R are positioned substantially mirror-symmetrically with respect to the plane P2. In practice, the outer contour (outer edge) of the lens 142L or 142R may include protrusions and indentations (remnants of molding gates or positioning notches) that have little effect on optical performance. Even with the presence of such protrusions and indentations, the effects of the present disclosure can be achieved, and these protrusions and indentations do not need to be mirror-symmetrical with respect to the plane P2.

[0050] exist Figure 3A In the figure, L11, L21, and L31 represent the minimum distances from the first, second, and third avoidance portions 142a, 142b, and 142c, respectively, to the optical axis O1. In HMD 1, distance L21 is equal to distance L31 (the second distance), and distance L11 (the first distance) is different from L21 and L31. That is, the second avoidance portion 142bL or 142bR and the third avoidance portion 142cL or 142cR are cut differently relative to the first avoidance portion 142aL or 142aR. For example, in a configuration where several avoidance portions are provided with different optimal cut sizes (such as a nose avoidance portion and a driver avoidance portion), the present disclosure allows each avoidance portion to have an ideal cut size. In particular, the effect of reducing viewing angle loss achieved in this case is significant. In other words, to better achieve the effects of the present disclosure, a preferred configuration is one in which two of the three avoidance portions have the same minimum distance from the optical axis O1, and the remaining avoidance portion has a different minimum distance.

[0051] In addition, in the above-mentioned HMD1, distance L11 is shorter than distance L21 and distance L31. The more the avoidance portion is cut, that is, the shorter the distance from the optical axis O1 to the outer edge of the avoidance portion in the optical element, the more the viewing angle will be lost. Therefore, in order to minimize the loss of viewing angle, it is preferable to make the avoidance portion small so that the distance between the outer edge and the optical axis is as long as possible. Two of the distances L11, L21, and L31 are equal. Therefore, L21 being longer than L11 means that L31 is equal to L21 and longer than L11, which helps to minimize the loss of viewing angle. That is, in order to better achieve the effects of the present disclosure, the preferred configuration is that two of the three avoidance portions have the same minimum distance from the optical axis O1, and the remaining avoidance portion has a shorter minimum distance.

[0052] As the viewing angle of images in HMDs has increased in recent years, the size of optical components has also increased. The cutout size of the nose avoidance, provided to avoid interference with the user's nose, has correspondingly tended to be large. Therefore, the avoidance portion 142a, avoidance portion 142b, and avoidance portion 142c with the shortest minimum distance from the optical axis O1 should preferably be positioned below the optical component and closer to the other display unit.

[0053] The horizontal viewing angle is considered to be the most important for users who view images in an HMD to perceive the spatial range. In HMD applications where users perform imaginary operations in CG space or MR space, a wide field of view at arm's length is also important. Figure 3B In this case, it is preferable to provide a wide user viewing angle in the horizontal direction indicated by direction D5 and on the lower side indicated by direction D6. In HMD 1, first avoidance portion 142a is positioned below lens 142 indicated by direction D1 and on the side closer to the other display unit indicated by direction D2. Second avoidance portion 142b is positioned below lens 142 indicated by direction D1 and on the side opposite to the other display unit indicated by direction D3. Third avoidance portion 142c is positioned near the upper end of lens 142 indicated by direction D4. Thus, each avoidance portion is positioned so as not to significantly reduce the viewing angle, thereby ensuring a wide horizontal field of view and a field of view at hand.

[0054] As described above, one of the three avoidance portions is preferably positioned on the lower side of the optical element and on a side close to another display unit, one avoidance portion is preferably positioned on the lower side of the optical element and on a side opposite to another display unit, and the remaining avoidance portion is preferably positioned near the upper end of the optical element.

[0055] The driver of HMD 1 includes a motor 135, which serves as an actuator that drives (generates a driving force to move) lens 142, serving as an optical element, in a predetermined direction. The driver also includes a guide rod 134, which serves as a guide mechanism that guides driven lens 142 in a predetermined direction. A keep-out portion provided on lens 142 abuts the driver comprising these components. In a drive mechanism, particularly the actuator that drives the object and the guide mechanism that guides the object typically occupy space along the drive direction and tend to be bulky. When the drive mechanism is configured in display unit 13, these actuators and guide mechanisms may increase the external size of display unit 13. Therefore, by providing keep-out portions in lenses 142L and 142R and placing the actuator and guide mechanism adjacent to these keep-out portions, it is possible to more effectively achieve the effect of miniaturization of display unit 13. As described above, the driver includes at least one of an actuator that drives the optical element in display unit 13 in a predetermined direction and a guide mechanism that guides the driven optical element in a predetermined direction, and preferably abuts the keep-out portion provided in the optical element.

[0056] Some actuators include portions that are preferably positioned away from each other. For example, if the two guide rods 134 are positioned away from each other, the two guide rods 134 can more accurately guide the lens 142. In HMD 1, the second avoidance portion 142b in the display unit 13 is adjacent to the motor 135 and one guide rod 134, while the third avoidance portion 142c is adjacent to the other guide rod 134. This configuration allows the actuators to be separated and positioned in separate avoidance portions, resulting in a smaller external shape for the display unit 13 and improving the positioning accuracy of the optical elements. As described above, the actuator that drives the optical elements in the display unit 13 is preferably adjacent to two of the avoidance portions, namely, the second avoidance portion 142b and the third avoidance portion 142c.

[0057] In addition to lens 142, display unit 13 also includes cover glass 143 as an optical element. The avoidance provided in lens 142 results in a loss of viewing angle for the user. Cover glass 143 is another optical element (second optical element) aligned with lens 142 (first optical element) along the optical axis. Therefore, providing the avoidance for cover glass at the same position (corresponding position) as the avoidance for lens 142 does not affect the viewing angle. This means that the avoidance can be provided at the same location as that for cover glass 143, allowing the driver and eye camera to be positioned there, making display unit 13 even smaller. As described above, display unit 13 includes multiple optical elements aligned along the optical axis, one of which includes a first avoidance 142a, a second avoidance 142b, and a third avoidance 142c in its outer contour. In this case, the other optical elements preferably have avoidances at positions corresponding to at least one of the first avoidance 142a, the second avoidance 142b, and the third avoidance 142c relative to optical axis O1.

[0058] Second embodiment

[0059] Next, an HMD 2 as a display device according to a second embodiment of the present disclosure will be described. The description of some matters in the second embodiment that are the same as those in the first embodiment may be omitted as appropriate. Matters not specifically described in the second embodiment should be understood to be the same as those in the first embodiment.

[0060] Figure 4A 2 is a perspective view of the HMD 2. Like the HMD 1, the HMD 2 is composed of an HMD main body 21 and an attachment band 22. Figure 4B This figure shows the HMD body 21 as viewed from the user. Similar to HMD 1, HMD 2 includes a pair of display units 23L and 23R. Similar to HMD 1, display units 23L and 23R present images to the user using displays 241L and 241R and optical elements (lenses 242L and 242R and cover glasses 243L and 243R).

[0061] Similar to HMD 1, the right-eye display unit 23R and the left-eye display unit 23L are constructed with mirror symmetry about a vertical axis. Components in the left-eye display unit 23L and the right-eye display unit 23R are given reference numerals with "L" and "R" appended to the end, respectively. In the following description of the display units 23L and 23R, when there is no need to distinguish between the left and right display units, the structure of the display units will be primarily described with respect to the left-eye display unit 23L, and the letter "L" may be omitted from the description. Various structures of the right-eye display unit 23R are identical to those of the left-eye display unit 23L.

[0062] refer to Figure 5A and Figure 5B The structures of the display units 23L and 23R of the HMD 2 are described. Figure 5A and Figure 5B 2 is an exploded perspective view of the left-eye display unit 23L. As described above, the letter "L" is omitted from the reference numerals in the drawings.

[0063] The display unit 23 is mainly composed of the following parts. The display unit 23 has the same configuration as the display unit 13 of the HMD 1 in terms of the display 241, lens 242, cover glass 243, display base 231, cover 232, lens holder 233, first guide rod 234, first motor 235, and first coupling member 236. The second guide rod 237, second motor 238, second coupling member 239, and eye camera 251 are parts not provided in the display unit 13 of the HMD 1.

[0064] The display 241 in the display unit 23 of the HMD 2 has the same configuration as the display 141 in the display unit 13 of the HMD 1. Similarly, the display base 231, the lens holder 233, the first guide rod 234, the first motor 235, and the first coupling member 236 have the same configuration as the display base 131, the lens holder 133, the guide rod 134, the motor 135, and the coupling member 136. In the HMD 2, as in the HMD 1, the lens 242 is moved in a direction substantially parallel to the optical axis O2 by a driver including the first motor 235, the first coupling member 236, and the first guide rod 234, thereby allowing the focus of the image to be changed.

[0065] The display unit 23 in the HMD 2 also includes a second motor 238, a second coupling member 239, two second guide rods 237, and two eye cameras 251. The cover 232 is held by two second guide rods 237 extending through the cover in the left-right direction indicated by D7 in the figure, and is held movable in direction D7. Both ends of the two second guide rods 237 are held by the HMD body 21 (not shown). The second motor 238 has a guide shaft 238a and is fixed to the HMD body 21 (not shown). The cover 232 holds a second coupling member 239 that is threadedly engaged with the guide shaft 238a of the second motor 238. When the guide shaft 238a is rotated by the second motor 238, the cover 232 moves in direction D7 via the second coupling member 239, thereby driving the lens 242, cover glass 243, and other peripheral mechanisms in direction D7.

[0066] As described above, in the display unit 23, a driver consisting of the second motor 238, the second coupling member 239, and the second guide rod 237 drives the lens 242 and cover glass 243, which serve as optical elements, in the left-right direction indicated by D7. This configuration allows the optical element to move in the left-right direction, providing a visual accommodation effect by placing the optical element in an optimal position relative to the user's left and right eyes. This improves image display performance. Hereinafter, in the HMD 2, the driver that drives the lens 242 in a direction substantially parallel to the optical axis O2 to adjust the image focus will be referred to as the first driver. The driver that drives the lens 242 and cover glass 243 in the left-right direction indicated by D7 to improve image display performance will be referred to as the second driver.

[0067] Similar to the actuator in HMD 1, the first actuator is configured to displace the position of the lens 242 (lens holder 233) in the display unit 23 (display base 231 and cover 232). The second actuator is configured to displace the position of the display unit 23 (display base 231 and cover 232) in the HMD body 21.

[0068] Two eye cameras 251 are mounted on the cover 232 to monitor the user's eyes. The eye monitoring results are used, for example, to calculate the target position of the lens 242 and cover glass 243 driven by the second driver, calculate the user's line of sight, and other processes in the HMD that use the line of sight information.

[0069] HMD2 has the following features: Figure 6A The following features are described. Figure 6A The left and right display units 23L and 23R are shown as viewed by a user along the optical axes O2L and O2R. Since this is an illustration of the internal structure, the outer contours of the display units 23L and 23R are shown with dashed lines. The lenses 242L and 242R have the same outer contours as the cover glasses 243L and 243R and are shown as overlapping.

[0070] In the display unit 23 of the HMD 2 of this embodiment, the lens 242 and cover glass 243, which are optical elements, include a first avoidance portion 242a, a second avoidance portion 242b, and a third avoidance portion 242c in their outer contours. In this embodiment, the first avoidance portion 242a, the second avoidance portion 242b, and the third avoidance portion 242c are portions of the non-circular optical element where the distance from the optical axis O2 is locally reduced.

[0071] More specifically, the first to third avoidance portions 242a, 242b, and 242c in this embodiment are formed as convex arc portions in the outer shape of the lens 242 when viewed along the optical axis, each convex arc portion having a radius of curvature greater than the outermost edge of an arc substantially along an imaginary circle around the optical axis O2. The phrase "convex arc portion" is used herein merely to describe the shape of each avoidance portion because it refers to the (two-dimensional) shape when viewed along the optical axis. Obviously, because the lens 242 has a thickness in the optical axis direction, each avoidance portion has an arched (curved) surface when described in three dimensions.

[0072] The second avoiding portion 242 b and the third avoiding portion 242 c are substantially mirror-symmetrical with respect to a plane P1 passing through the center of the first avoiding portion 242 a and the optical axis O2 .

[0073] In this embodiment, among the avoidance portions 242a, 242b, and 242c, the first avoidance portion 242a is positioned below the lens 242 and cover glass 243 as indicated by the direction D1 and on the side closer to the other display unit (display unit 23R) as indicated by the direction D2. The second avoidance portion 242b is positioned adjacent to some parts of the first driver (the first motor 235, the first guide rod 234, and the first coupling member 236) and the eye camera 251. The third avoidance portion 242c is positioned adjacent to some parts of the first driver (the first guide rod 234) and some parts of the second driver (the second motor 238, the second guide rod 237, and the second coupling member 239).

[0074] In the two display units 23L and 23R, the lenses 242L and 242R having these avoidance portions and the cover glasses 243L and 243R are positioned substantially mirror-symmetrically with respect to a plane P2 perpendicular to the left-right direction.

[0075] Similar to the HMD 1 of the first embodiment, the HMD 2 of the present embodiment allows the first avoidance portion 242 a and the second avoidance portion 242 b to have different notch shapes while enabling the left and right optical elements to have the same shape.

[0076] Figure 6B 2 is a diagram illustrating the viewing angles of an image viewed by a user on the left-eye display unit 23. A21 represents the viewing angle area of ​​the image visible to the user. A22 represents the viewing angle area lost due to the provision of the second avoidance portion 242b. A23 represents the viewing angle area lost due to the provision of the third avoidance portion 242c.

[0077] Now let's compare Figure 6B The viewing angle of the HMD2 shown is the same as Figure 7B By forming the second avoidance portion 242b as the driver avoidance portion into the minimum necessary gap, the loss of viewing angle can be reduced from Figure 7B The area A92 in the Figure 6B Area A22 in. Figure 6B Region A23 in the HMD is no longer present due to the provision of third avoidance portion 242c. Even so, the loss of viewing angle (the combined area of ​​regions A22 and A23) is reduced. This prevents the unnecessary reduction in viewing angle, a problem in HMDs, while achieving miniaturization and cost reduction.

[0078] In the HMD 2, the second avoidance portion 242b is adjacent to one of the two eye cameras 251 (the first camera). It is preferable to place the eye camera 251 as close to the optical axis O2 as possible to monitor the eye without the eyelid or eyelashes obstructing the pupil. Providing the eye camera adjacent to the second avoidance portion 242b in the optical element allows the eye camera to be placed close to the optical axis O2. Therefore, it is preferable to position one of the second avoidance portion 242b and the third avoidance portion 242c adjacent to the eye camera.

[0079] In the HMD 2, the first avoidance portion 242a is adjacent to the other eye camera (second camera) of the two eye cameras 251. This camera 251 is positioned at substantially the same height as the optical axis O2, that is, by being adjacent to the first avoidance portion 242a, the camera can be positioned close to the optical axis O2.

[0080] In HMD 2, a first actuator drives lens 242, an optical element included in display unit 23, in a direction substantially parallel to optical axis O2. A second actuator drives lens 242 and cover glass 243, optical elements included in display unit 23, in the left-right direction indicated by D7. A keep-out portion provided in the optical element is adjacent to these actuators. The first actuator allows the focal length of an image to be changed, while the second actuator can help improve image display performance. At least one of these actuators is preferably positioned adjacent to the keep-out portion in the optical element, so that the aforementioned visual accommodation effect can be achieved while allowing for miniaturization of the HMD.

[0081] In the HMD 2, the second avoidance portion 242b is adjacent to portions of the first driver that drives the lens 242, serving as an optical element, in a direction substantially parallel to the optical axis O2. The third avoidance portion 242c is adjacent to portions of the second driver that drives the lens 242 and cover glass 243, serving as optical elements, in the left-right direction. Positioning the first and second drivers adjacent to the same avoidance portion would result in a local increase in size in the display unit 23. Therefore, disposing at least portions of independent drivers adjacent to the second avoidance portion 242bL or 242bR and the third avoidance portion 242cL or 242cR is preferred, as it enables the display unit to be kept compact even with two or more drivers.

[0082] Other preferred configurations for better achieving the effects of the present disclosure are the same as those in the HMD 1 .

[0083] When possible, various configurations of the above-described embodiments may be combined.

[0084] While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A display device, comprising: a pair of display units configured to present images to a left eye and a right eye, each of the pair of display units including an optical element, Wherein, the optical element includes The first avoidance portion, the second avoidance portion, and the third avoidance portion are arranged at different positions of the outer edge of the optical element when viewed along the optical axis, and have A shape that is substantially mirror-symmetrical with respect to an imaginary plane passing through a point on the first avoidance portion and the optical axis.

2. The display device according to claim 1, wherein The first avoidance portion is provided at a position facing the nose.

3. The display device according to claim 1 or 2, wherein: The point on the first avoidance portion is a center of a contour of the first avoidance portion.

4. The display device according to claim 1 or 2, wherein: When viewed along the optical axis, The minimum distance from the first avoidance portion to the optical axis is defined as a first distance, and Each of a minimum distance between the second avoidance portion and the optical axis and a minimum distance between the third avoidance portion and the optical axis is defined as a second distance, and the second distance is different from the first distance.

5. The display device according to claim 4, wherein The first distance is shorter than the second distance.

6. The display device according to claim 1 or 2, wherein: The first avoiding portion is provided on a lower side of the optical element and on a side where the pair of optical elements face each other.

7. The display device according to claim 6, wherein The second avoiding portion is provided on a lower side of the optical element and on a side opposite to a side where the pair of optical elements face each other.

8. The display device according to claim 7, wherein The third avoidance portion is provided on an upper side of the optical element.

9. The display device according to claim 1 or 2, in, The display units each include a driver configured to displace the optical element in a predetermined direction, and The second avoidance portion and the third avoidance portion are both arranged at positions facing at least a portion of the driver.

10. The display device according to claim 9, in, The driver includes: an actuator configured to generate a driving force for displacing the optical element; and a guide mechanism configured to guide the optical element so that the optical element is displaced in the predetermined direction, wherein the second avoiding portion is provided at a position at least facing the actuator, Wherein, the third avoidance portion is provided at a position at least facing the guide mechanism.

11. The display device according to claim 9, wherein The predetermined direction is a direction substantially parallel to the optical axis or a direction in which the pair of optical elements are arranged.

12. The display device according to claim 9, further comprising a main body configured to hold the display unit, in, The driver includes: a first driver configured to displace the optical element in each of the display units; and a second driver configured to displace a display unit in the main body, wherein the first drive displaces the optical element in a direction substantially parallel to the optical axis, and The second driver shifts the display unit in a direction in which the pair of optical elements are arranged.

13. The display device according to claim 1 or 2, in, The display units each include a camera for monitoring the eyes, and Wherein, one of the second avoiding portion and the third avoiding portion is arranged at a position facing the camera.

14. The display device according to claim 13, in, The camera includes a first camera and a second camera, wherein one of the second avoiding portion and the third avoiding portion is arranged at a position facing the first camera, and Wherein, the first avoiding portion is arranged at a position facing the second camera.

15. The display device according to claim 1 or 2, wherein: The escape portion is a portion that is recessed toward the optical axis from the outermost portion substantially along an arc of an imaginary circle surrounding the optical axis when viewed in the optical axis direction.

16. The display device according to claim 15, wherein The avoidance portion is a linear portion in the outer edge shape of the optical element when viewed along the optical axis direction.

17. The display device according to claim 15, wherein The avoidance portion is a convex arc portion having a larger curvature radius than the outermost portion in the outer edge shape of the optical element when viewed in the optical axis direction.

18. The display device according to claim 1 or 2, in, In the case where the optical element is defined as a pair of first optical elements, The pair of display units further includes a pair of second optical elements, the second optical elements are arranged along the optical axis direction relative to the pair of first optical elements, and The second optical element includes a avoidance portion at a position corresponding to at least one of the first avoidance portion, the second avoidance portion, and the third avoidance portion.

19. An optical element provided in each of a pair of display units in a display device that present images to a left eye and a right eye, the optical element comprising: a first avoidance portion, a second avoidance portion, and a third avoidance portion provided at different positions in the outer edge of the optical element when viewed along the optical axis direction; The optical element has a shape that is substantially mirror-symmetrical with respect to an imaginary plane passing through the center of the first avoidance portion and the optical axis.

Images