Japanese Patent Application No. 2015-193705 filed on Sep. 30, 2015, is hereby incorporated by reference in its entirety.
The present invention relates to a wearable device and the like.
A wearable device (head-mounted display) that is worn on the head of the user and projects an image within the field of view of the user is known. For example, JP-A-2004-236242, JP-A-2001-108935, and JP-A-2006-3879 disclose technology that relates to such a wearable device.
JP-A-2004-236242 discloses a configuration in which a support arm is attached to an ear pad (sound output section) of a headphone through a hinge, and the support arm supports an image output section. The image output section can be moved from the side (or the upper side) to the front side of the face by rotating the support arm through the hinge JP-A-2001-108935 discloses a configuration in which an arm is attached to a head band through a ball and a ball bearing, and a viewer is attached to the arm through a hinge The arm can be rotated in an arbitrary direction by utilizing the ball and the ball bearing, and the viewer can be rotated around an approximately vertical axis by utilizing the hinge.
JP-A-2006-3879 discloses a pupil-division see-through-type head-mounted display. The technology disclosed in JP-A-2006-3879 significantly reduces the size of an eyepiece element (eyepiece window) that projects (emits) a virtual image of a display image to implement see-through display (i.e., display in which the external field of view and the display image overlap each other), and see-around display (i.e., display in which a wide external field of view is provided).
a wearable element that is worn on a head of a wearer;
a connector that is connected to the wearable element so as to be rotatable around a first rotation axis; and
a display that is connected to the connector so as to be rotatable around a second rotation axis, and displays a virtual image within part of a field of view of the wearer,
wherein a relationship “20 mm≦L1+L2≦45 mm” is satisfied provided that a plane that includes an eyepiece optical axis of the display and intersects the first rotation axis and the second rotation axis is referred to as a virtual plane, a distance from a first intersection that is an intersection of the virtual plane and the first rotation axis to a second intersection that is an intersection of the virtual plane and the second rotation axis is referred to as L1, and a distance from the second intersection to an intersection of an eyepiece and the eyepiece optical axis is referred to as L2.
According to another aspect of the invention, there is provided a wearable device comprising:
a wearable element that is worn on a head of a wearer;
a connector that is connected to the wearable element so as to be rotatable around a first rotation axis; and
a display that is connected to the connector so as to be rotatable around a second rotation axis, and displays a virtual image within part of a field of view of the wearer,
wherein the first rotation axis passes through an eyeball of the wearer when the wearable element is worn on the head, and
a relationship “L1≧5×L2” is satisfied provided that a plane that includes an eyepiece optical axis of the display and intersects the first rotation axis and the second rotation axis is referred to as a virtual plane, a distance from a first intersection that is an intersection of the virtual plane and the first rotation axis to a second intersection that is an intersection of the virtual plane and the second rotation axis is referred to as L1, and a distance from the second intersection to an intersection of an eyepiece and the eyepiece optical axis is referred to as L2.
According to another aspect of the invention, there is provided a wearable device comprising:
a wearable element that is worn on a head of a wearer; and
a display that displays a virtual image within part of a field of view of the wearer,
wherein the display is connected to the wearable element so as to be rotatable around a rotation axis that is orthogonal to a virtual plane that is a plane that includes an eyepiece optical axis of the display, and
a condition “L2≧5 mm” is satisfied provided that a distance from an intersection of the rotation axis and the virtual plane to an intersection of an eyepiece and the eyepiece optical axis is referred to as L2.
An object of several aspects and embodiments of the invention is to provide a wearable device that can simplify an adjustment that adjusts the position of an eyepiece element with respect to a human eye to a position (area) based on ergonomics, and causes the optical axis of the eyepiece element to (approximately) coincide with the visual axis of the user.
According to the above configuration, since the first rotation axis and the second rotation axis are provided at the ergonomically optimum positions, it is possible to place the eyepiece element in an optimum area by performing the first-step operation. In this case, when the optical axis of the eyepiece element and the line of sight of the user (approximately) coincide with each other, it is possible to immediately observe the display image through the eyepiece element without making an adjustment. Even when the optical axis of the eyepiece element and the line of sight of the user do not (approximately) coincide with each other (i.e., part of the display image cannot be observed), it is possible to immediately (easily) cause the optical axis of the eyepiece element and the line of sight of the user to coincide with each other by performing the second-step operation.
Exemplary embodiments of the invention are described below. Note that the following exemplary embodiments do not in any way limit the scope of the invention laid out in the claims. Note also that all of the elements described below in connection with the exemplary embodiments should not necessarily be taken as essential elements of the invention.
The wearable device 100 includes a wearable element that is worn on the head 70 of the wearer, a connector 130 that is connected to the wearable element so as to be rotatable around a first rotation axis 10, and a display 140 that is connected to the connector 130 so as to be rotatable around a second rotation axis 20, and displays a virtual image within part of the field of view of the wearer.
In the configuration example illustrated in
The connector 130 is an element that connects the wearable element and the display 140. The connector 130 supports the display 140 (eyepiece window 142) in front of an eyeball 60 and the front of the eyeglass-type frame 150. When the wearable element is the neck band 170, the connector 130 supports the display 140 in front of the eyeball 60. The connector 130 and the wearable element are connected through a rotation mechanism (e.g., shaft (shaft protrusion) and bearing), and the rotation (rotation in both directions (clockwise direction and counterclockwise direction)) around the first rotation axis 10 is implemented by means of the rotation mechanism. Likewise, the display 140 and the connector 130 are connected through a rotation mechanism (e.g., shaft (shaft protrusion) and bearing), and the rotation around the second rotation axis 20 is implemented by means of the rotation mechanism.
The connector 130 includes a rod-like member (that may be curved or bent, and may have a non-uniform thickness), for example. A first end (i.e., one end) of the rod-like member is connected to the display 140, and a second end (i.e., the other end) of the rod-like member is connected to the wearable element. Alternatively, the first end of the rod-like member may be connected to the display 140, and an area of the rod-like member that is situated between the first end and the second end may be connected to the wearable element. Note that the shape and the connection positions of the connector 130 are not limited to the examples described above.
The display 140 is configured to guide light (image) output from a display device to the eyepiece window 142 through an optical system, and emit the guided light from the eyepiece window 142 toward the pupil of the eyeball 60 (i.e., emit the guided light in the direction along the line of sight of the eyeball 60 (visual axis direction)) to display an enlarged virtual image of the image within the field of view (i.e., project the image onto the retina). The display device may be implemented by a liquid crystal display device, a self-emitting display device (e.g., EL display device), or a scanning-type display device that scans the retina with spot light, for example. Note that the term “line of sight” used herein refers to a line that connects the eyeball 60 and the viewing target object, or refers to the viewing direction of the eyeball 60. More specifically, the term “line of sight” used herein refers to a line that extends along the optical axis of the eyeball 60 when the viewing target object is being viewed, or refers to a direction that extends along the optical axis. The term “visual axis” used herein refers to the optical axis of the eyeball 60.
As illustrated in
As illustrated in
Since the pupil-division see-through optical system displays an image within part of the field of view (e.g., within a field of view (viewing angle) of 10 to 15°), it is possible to display the image in the peripheral area of the field of view instead of the center of the field of view. Specifically, the wearer can read the information displayed within the image by optionally observing the eyepiece window 142 situated in the peripheral area of the field of view while maintaining a clear sight at the center of the field of view. When an optical system that allows the wearer to arbitrarily change the display position is used, it is considered that the wearer positions the eyepiece window 142 (display position) when the head-mounted display has been worn, or changes the position of the eyepiece window 142 (display position) during use, for example. In this case, it is necessary to make an adjustment so that the entire image can be observed.
For example, when the wearer desires to display the image on the upper side with respect to the center of the field of view, the wearer positions the eyepiece window 142 on the upper side with respect to the center of the eye (see
The wearable device 100 according to one embodiment of the invention that is provided with the first rotation axis 10 and the second rotation axis 20 can solve the above problem as described below.
A virtual plane 30 is a (virtual) plane that includes an eyepiece optical axis 40 of the display 140 and intersects the first rotation axis 10 and the second rotation axis 20. A first intersection 12 is the intersection of the virtual plane 30 and the first rotation axis 10. A second intersection 22 is the intersection of the virtual plane 30 and the second rotation axis 20. A distance L1 is the distance from the first intersection 12 to the second intersection 22, and a distance L2 is the distance from the second intersection 22 to an exit end 144 of the eyepiece optical axis 40 (an intersection of an eyepiece and the eyepiece optical axis 40).
The eyepiece optical axis 40 is the optical axis of the eyepiece-side end (eyepiece window 142) of the display 140. Since the display 140 is configured so that the light (image) is reflected (or refracted) within the optical system in order to guide the light (image) to the eyepiece window 142, the direction of the optical axis changes each time the reflection (or refraction) occurs. The eyepiece optical axis 40 is the optical axis of the part that emits the light toward the eye. The exit end of the eyepiece optical axis 40 corresponds to the intersection of the part of the optics that emits the light toward the eye, and the eyepiece optical axis 40. For example, when an eyepiece lens is provided to the eyepiece window 142, and the eyepiece lens is the final optical element, the exit end is the intersection of the eyepiece lens and the eyepiece optical axis 40. When a prism or a mirror is provided on the inner side of the eyepiece window 142, and the prism or the mirror is the final optical element, the exit end is the intersection of the prism or the mirror and the eyepiece optical axis 40.
The distance L1 and the distance L2 defined as described above satisfy the relationship “20 mm≧L1+L2≧45 mm”. Note that the distance L1 and the distance L2 desirably satisfy the relationship “30 mm≧L1+L2≧35 mm”
It is considered in terms of ergonomics that the radius of the eyeball 60 is about 12 mm, the distance from the pupil of the eyeball 60 to the eyeglass lens is about 12 mm, and the dimension of the space required to prevent a situation in which the display 140 comes in contact with the eyeglass lens when the display 140 is rotated around the first rotation axis 10 is about 6 mm Since the sum of the radius of the eyeball 60, the distance from the pupil of the eyeball 60 to the eyeglass lens, and the dimension of the space is about 30 mm, the first rotation axis 10 passes through a point around an eyeball center 64 when the value “L1+L2” is set to about 30 mm. Note that these values are average values determined in terms of ergonomics, and may vary due to individual variations, the shape of the wearable element, and the like. Specifically, various design values are ergonomically determined so that the first rotation axis 10 passes through a point around the eyeball center 64 when designing the wearable device.
The distance L1 and the distance L2 may be set so that the relationship “about 20 mm<L1+L2<about 45 mm” is satisfied, for example The lower limit (20 mm) is set taking account of the case where an eyeglass lens is not provided (e.g., neck band 170), and the upper limit (45 mm) is set taking account of practical utility and the like.
More specifically, the lower limit (20 mm) is calculated by adding up the radius (about 12 mm) of the eyeball 60 and the dimension (about 8 mm) of the space required to prevent a situation in which the display 140 comes in contact with the eyelashes. The upper limit (45 mm) is set taking account of the limit by which the entire virtual image can be observed through the eyepiece window 142 in addition to the fact that the value “L1+L2” increases due to a usage state in which protective glasses are worn over the eyeglasses, the racial difference in the distance from the eyeball center to the eyeglass lens, and the like. For example, when the width of the eyepiece window 142 is set to 4 mm, and the value “L1+L2” is set to 45 mm, the viewing angle with respect to the widthwise direction of the eyepiece window 142 is about 5.1°. Since the field of view of the pupil-division see-through optical system in the widthwise direction (i.e., vertical field of view) is typically 5 to 9°, it is difficult to observe the image through the center of the pupil when the value “L1+L2” is larger than 45 mm Moreover, the size of the eye-box (i.e., a range in which the entire image can be observed even if the position of the eye has changed) significantly decreases, and it becomes necessary to make a severe adjustment with regard to the visual axis and the eyepiece optical axis. Therefore, it is practically difficult to set the value “L1+L2” to be larger than 45 mm. The upper limit (45 mm) is set also taking account of a situation in which the support strength decreases or operation is hindered if the display 140 is significantly situated away from the eyeglasses, and the display swings to a large extent along with the motion of the head due to an increase in moment, for example. Note that each of the above values varies depending on individual variations and the like, and the lower limit (20 mm) and the upper limit (45 mm) may be changed to some extent.
In any case, when the first rotation axis 10 and the second rotation axis 20 are provided so that the relationship “20 mm<L1+L2<45 mm” is satisfied, it is possible to implement a state in which the first rotation axis 10 passes through a point around the eyeball center 64. When the first rotation axis 10 and the second rotation axis 20 are provided in such a manner, it is possible to easily adjust the angle of the eyepiece optical axis 40 (i.e., make an adjustment that causes the line of sight and the eyepiece optical axis 40 to approximately coincide with each other when the pupil 62 (line of sight) has been turned on the virtual image 50). When the first rotation axis 10 passes through a point around the eyeball center 64, the display image can be observed even if the display position has been changed after an adjustment has been made so that the display image can be observed.
Specifically, the wearer (user) adjusts the display position to the desired position by rotating the display 140 around the first rotation axis 10 (see the upper part of
As described above, since the first rotation axis 10 and the second rotation axis 20 are provided at the ergonomically optimum positions, it is possible to place the eyepiece element in an optimum area by performing the first-step operation (see the upper part of
In one embodiment of the invention, the distance L1 and the distance L2 are set to satisfy the relationship “L1≧5×L2”. Specifically, the ratio “L1/L2” of the distance L1 to the distance L2 is larger than 5. It is most ideal that the distance L2 be 0 mm (L2=0 mm)
As illustrated in
tan α=L2×sin β/(D−L2+L2×cos β) (1)
Since the change a in elevation angle and the correction angle β are equal to or less than about 10°, the following expression (2) is approximately satisfied based on the expression (1). Note that the change a in elevation angle and the correction angle β are exaggerated in
α=L2×β/D (2)
When the first rotation axis 10 passes through a point around the eyeball center, the distance D can be approximated to the distance “L1+L2”. When L1≦P×L2, the following expression (3) is satisfied based on the expression (2).
α⊖β/(P+1) (3)
The change α in elevation angle corresponds to the change in display position due to the alignment adjustment. It is preferable that the change in display position due to the alignment adjustment be as small as possible. When P=5, and the correction angle β is approximately equal to the field of view in the vertical direction (hereinafter may be referred to as “vertical FOV”) with respect to the display image (i.e., one screen in the vertical direction), the relationship “α≦β/6” is satisfied (i.e., the change in elevation angle is smaller than ⅙th of the vertical FOV (i.e., ⅙th of the screen in the vertical direction)). Since the vertical FOV when using the pupil-division see-through optical system is about 5 to 9°, the change a in elevation angle is smaller than 1.5°, and a change in display position occurs to only a small extent even when the alignment adjustment is performed corresponding to one screen in the vertical direction. When the value P is sufficiently larger than 5 (i.e., L1>>L2), the change a in elevation angle is approximately 0° (i.e., a change in elevation angle due the alignment adjustment does not occur (i.e., a change in display position does not occur)).
As described above, it is possible to reduce a change in display position due to the alignment adjustment by providing the first rotation axis 10 and the second rotation axis 20 so that the relationship “L1≧5×L2” is satisfied. Specifically, when performing the two-step adjustments described above with reference to
In one embodiment of the invention, the distance L2 is set to be equal to or less than 5 mm (L2≦5 mm).
The condition “L2=5 mm” is obtained by applying a typical value “L1+L2=30 mm” to L1=5×L2 (P=5). Specifically, when the distance L2 is set to be equal to or less than 5 mm (L2≦5 mm), it is possible to reduce a change in display position due to the alignment adjustment (as described above with reference to
According to one embodiment of the invention, the virtual plane 30 that includes the eyepiece optical axis 40 and the first rotation axis 10 are (approximately) orthogonal to each other, and the virtual plane 30 and the second rotation axis 20 are (approximately) orthogonal to each other (see
When the virtual plane 30 are orthogonal to both the first rotation axis 10 and the second rotation axis 20, the first rotation axis 10 and the second rotation axis 20 are orthogonal to the eyepiece optical axis 40, and are parallel to each other.
When the first rotation axis 10 is tilted with respect to the eyepiece optical axis 40, a component of rotation around the axis orthogonal to the eyepiece optical axis 40 and a component of rotation around the eyepiece optical axis 40 are mixed when the display 140 is rotated around the first rotation axis 10. Therefore, the display image is rotated around the eyepiece optical axis 40 due to the component of rotation around the eyepiece optical axis 40, and it is necessary to provide a further adjustment mechanism that corrects the rotation of the display image. This also applies to the case where the second rotation axis 20 is tilted with respect to the eyepiece optical axis 40. According to one embodiment of the invention, since the first rotation axis 10 and the second rotation axis 20 are (approximately) orthogonal to the eyepiece optical axis 40, the rotation of the display image around the eyepiece optical axis 40 rarely occurs when an adjustment around the first rotation axis 10 or the second rotation axis 20 is performed.
When the first rotation axis 10 does not exactly pass through the eyeball center 64, the eyepiece optical axis 40 is shifted from the eyeball center 64 when the display 140 is rotated around the first rotation axis 10. In this case, the shift of the eyepiece optical axis 40 from the eyeball center 64 occurs in a plane that passes through the eyepiece optical axis 40 and is orthogonal to the first rotation axis 10. Likewise, when the direction of the eyepiece optical axis 40 is adjusted around the second rotation axis 20, the movement of the eyepiece optical axis 40 occurs in a plane that passes through the eyepiece optical axis 40 and is orthogonal to the second rotation axis 20.
According to one embodiment of the invention, since the first rotation axis 10 and the second rotation axis 20 are parallel to each other, the movement of the eyepiece optical axis 40 occurs in an identical plane (virtual plane 30), and the direction of the eyepiece optical axis 40 that has been shifted due to the movement of the display position around the first rotation axis 10 can be adjusted around the second rotation axis 20 (i.e., alignment adjustment).
According to one embodiment of the invention, the virtual plane 30 is parallel to the vertical scan direction DV of the image that is displayed as the virtual image 50 (see
The display device is configured to repeat an operation that sequentially selects the pixels along the scan line, and writes the pixel value into the selected pixels to display an image that corresponds to one screen. The direction that extends along the scan line is referred to as “horizontal scan direction”, and the direction that is orthogonal to the horizontal scan direction is referred to as “vertical scan direction”. The horizontal scan direction DH and the vertical scan direction DV illustrated in
The vertical scan direction DV normally approximately coincides with the upward-downward direction of the field of view of the wearer. Since the virtual plane 30 is parallel to the vertical scan direction DV, the first rotation axis 10 that is orthogonal to the virtual plane approximately coincides with the rightward-leftward direction of the field of view. In this case, when the first rotation axis 10 of the eyeglass-type frame 150 illustrated in
According to one embodiment of the invention, it suffices that the first rotation axis 10 pass through the eyeball 60 of the wearer when the wearable element is worn on the head 70.
Although an example in which the first rotation axis 10 passes through a point around the eyeball center 64 as a result of providing the first rotation axis 10 and the second rotation axis 20 so that the relationship “L1+L2=30 mm” is satisfied has been described above with reference to
Since the position of the eyeball 60, the positional relationship between the eyeball 60 and the ear 80 or the nose, the radius of the eyeball 60, and the like differ between individuals, the positional relationship between the first rotation axis 10 and the eyeball 60 also differs between individuals when an identical wearable device 100 is used. Therefore, it suffices that the wearable device 100 be designed so that the first rotation axis 10 passes through the eyeball 60 of 90% of the wearers, for example.
According to one embodiment of the invention, the first rotation axis 10 is a rotation axis around which the display 140 is rotated to adjust the display position of the virtual image 50 within the field of view (see
Although the positional conditions with regard to the first rotation axis 10 and the second rotation axis 20 that implement the above functions have been described above with reference to
The detailed configuration of each section of the wearable device 100 and various modifications are described below.
When implementing the front view configuration, the eyepiece optical axis 40 that passes through the eyeball center 64 corresponds to the forward-backward direction (situated in the DZ-DY plane). Specifically, the display image is displayed at the center of the field of view, or displayed in the vicinity of the center of the field of view in the upward-downward direction. When implementing the right side view configuration, the eyepiece optical axis 40 that passes through the eyeball center 64 is tilted to the right. Specifically, the display image is displayed on the right side of the center of the field of view, or displayed in the vicinity of the right side of the center of the field of view in the upward-downward direction. When implementing the front view configuration and the right side view configuration, the distance from the eyeball center 64 to the eyepiece window 142 is about 30 mm (=12 mm+12 mm+6 mm) The distance between a symmetry plane 152 of the eyeglass-type frame 150 (wearable element) and the eyeball center 64 is about 26 to 36 mm (see
The optical system according to the first configuration example includes a display panel 146 and a prism PR1. The prism PR1 guides light from the display panel 146 to the eyepiece window 142 while reflecting the light within the prism PR1 a plurality of times. The prism PR1 has a positive diopter (power or refractive power) due to the incident end face and the shape of the reflection plane to project the virtual image onto the eye. According to the first configuration example, the end face of the prism PR1 through which the light exits from the optical system corresponds to the eyepiece window 142, and the intersection of the end face and the eyepiece optical axis 40 (exit optical axis) corresponds to the exit end 144 of the eyepiece optical axis 40. The optical system according to the first configuration example is configured so that the optical axis of the display panel 146 and the eyepiece optical axis 40 form an acute angle, and the light is guided by the prism PR1, and the display 140 has a shape along the curved surface of the eyeglass frame.
The optical system according to the second configuration example includes a display panel 146, a lens LN1, and a mirror MR1. Light from the display panel 146 passes through the lens LN1 that has a positive diopter, is reflected by the mirror MR1, and exits from the optical system through the eyepiece window 142. According to the second configuration example, the opening of the housing through which the light reflected by the mirror MR1 exits from the optical system corresponds to the eyepiece window 142. The intersection of the reflection plane of the mirror MR1 and the eyepiece optical axis 40 corresponds to the exit end 144 of the eyepiece optical axis 40. The optical system according to the second configuration example is configured so that the mirror MR1 reflects the light (bends the optical axis) at an acute angle, and the display 140 is formed to follow the curved surface of the eyeglass frame as much as possible.
The optical system according to the third configuration example includes a display panel 146, a lens LN2, and a prism PR2. Light from the display panel 146 passes through the lens LN2, enters the prism PR2, is reflected by the reflection plane of the prism PR2, and exits from the optical system through the end face of the prism PR2. The optical system has a positive diopter due to the shape of the incidence plane of the prism PR2 and the lens LN2. According to the third configuration example, the end face of the prism PR2 through which the light exits from the optical system corresponds to the eyepiece window 142, and the intersection of the end face and the eyepiece optical axis 40 corresponds to the exit end 144 of the eyepiece optical axis 40. The optical system according to the third configuration example is configured so that the prism PR2 reflects the light (bends the optical axis) at an acute angle, and the display 140 is formed to follow the curved surface of the eyeglass frame as much as possible.
The first rotation axis 10 can be implemented using a similar configuration. In the example illustrated in
Note that a bearing that corresponds to the second rotation axis 20 may be provided to the display 140. A bearing that corresponds to the first rotation axis 10 may be provided to the temple. The eyeglass-type frame 150 may have a configuration in which the front and the temple are integrally formed without providing a hinge, and a bearing that corresponds to the first rotation axis 10 is provided to the frame that is integrally formed.
The first arrangement example may be employed when implementing the display 140 having a linear shape as illustrated in
The second arrangement example may be employed when implementing the display 140 having a curved shape as illustrated in
When implementing the display 140 having a linear shape, the second rotation axis 20 may be provided to pass through a position situated on the side of the wearer with respect to the exit end 144 of the eyepiece optical axis 40 (see the second arrangement example). When implementing the display 140 having a curved shape, the second rotation axis 20 may be provided to pass through the exit end 144 of the eyepiece optical axis 40 (see the first arrangement example).
The link mechanism includes two shafts 14 and 15, and each shaft and the display 140 are connected through links RK1 and RK2 (that correspond to the connector 130).
The second rotation axis 20 may be implemented as described below, for example. Specifically, the links RK1 and RK2 may be connected through a third link, the third link and the housing of the display 140 may be connected through a rotation mechanism, and the rotation axis of the rotation mechanism may be used as the second rotation axis 20.
The wearable device 100 includes a wearable element that is worn on the head of the wearer, and a display 140 that displays a virtual image within part of the field of view of the wearer. The display 140 is connected to the wearable element so as to be rotatable around a rotation axis (second rotation axis 20) that is orthogonal to a virtual plane 30 that is a plane that includes an eyepiece optical axis 40 of the display 140. The condition “L2≦5 mm” is satisfied when the distance from the intersection of the rotation axis 20 and the virtual plane 30 to an exit end 144 of the eyepiece optical axis 40 is referred to as L2. The eyepiece optical axis 40, the virtual plane 30, the exit end 144, and the distance L are the same as defined above (see
More specifically, the wearable element is the eyeglass-type frame 150. The display 140 is provided to a rim 158 of the eyeglass-type frame 150. The display 140 may be implemented using a long and narrow optical system (e.g., pupil-division see-through optical system).
The rim 158 is a frame that is provided to the front of the eyeglass-type frame 150, and used to hold a lens. Note that only the frame may be provided without providing a lens.
The display 140 is embedded in the rim 158 on the inner side (side closer to the face) of the rim 158, for example. The display 140 cannot be observed directly from the outer side (front side). The rim and the display 140 are connected through a rotation mechanism (e.g., bearing and shaft). Since the display 140 is embedded in the rim 158, it is preferable that the rotation axis 20 be provided around the center of the long and narrow display 140. For example, the rotation axis 20 passes through the intersection of the reflection plane of a mirror or a prism provided at the exit end, and the eyepiece optical axis (i.e., the center of the cross section of the minor or the prism).
According to the second configuration example, only one rotation axis (rotation axis 20) is used for the adjustment. However, it can be considered that a virtual rotation axis exists around the ear piece of the temple of the eyeglass-type frame 150. The rotation around the virtual rotation axis apparently occurs due to individual variations and the like, and is not intentionally adjusted by the user. The virtual rotation axis is (approximately) parallel to the rightward-leftward direction of the head 70, and the rotation axis 20 is provided (approximately) parallel to the rightward-leftward direction of the head 70. Therefore, the display 140 is provided to the upper part or the lower part of the rim 158 that surrounds the lens.
Note that the display 140 need not necessarily be embedded in the rim 158 of the eyeglass-type frame 150. The second configuration example can be applied as long as only the rotation mechanism that utilizes the second rotation axis 20 is provided, and the condition “L2≦5 mm” is satisfied.
As illustrated in
tan α=L2×sin β/(D−L2+L2×cos β) (4)
Since the change α in elevation angle and the correction angle β are equal to or less than about 10°, the following expression (5) is approximately satisfied based on the expression (4). Note that the change α in elevation angle and the correction angle β are exaggerated in
α=L2×β/D (5)
When the display 140 is embedded in the rim 158 of the eyeglass-type frame 150, the distance D is about 25 mm≦D≦about 30 mm. Therefore, when L2≦5 mm, the change ≢0 in elevation angle is about ⅕th of the correction angle β. Specifically, when the correction angle β is approximately equal to the vertical FOV, the change a in elevation angle due to the alignment adjustment is approximately equal to ⅕th of the vertical FOV. Since the vertical FOV of the pupil-division see-through optical system is about 5 to 9°, the change a in elevation angle is about 1 to 1.8°, and a change in display position due to the alignment adjustment occurs to only a small extent.
According to the second configuration example, it is possible to implement a head-mounted display using a simple design that embeds the display 140 in the rim 158 of the eyeglass-type frame 150. Since the display 140 is secured on the rim 158, it is necessary to make the alignment adjustment due to individual variations. However, since the rotation axis 20 is provided so that the condition “L2≦5 mm” is satisfied, it is possible to cause the eyepiece optical axis 40 and the line of sight to coincide with each other through a simple adjustment.
The embodiments to which the invention is applied and the modifications thereof have been described above. Note that the invention is not limited to the above embodiments and the modifications thereof. Various modifications and variations may be made without departing from the scope of the invention. A plurality of elements described in connection with the above embodiments and the modifications thereof may be appropriately combined to implement various configurations. For example, some elements may be omitted from the elements described in connection with the above embodiments and the modifications thereof. Some of the elements described above in connection with different embodiments or modifications thereof may be appropriately combined. Specifically, various modifications and applications are possible without materially departing from the novel teachings and advantages of the invention. Any term cited with a different term having a broader meaning or the same meaning at least once in the specification and the drawings can be replaced by the different term in any place in the specification and the drawings.
Number | Date | Country | Kind |
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2015-193705 | Sep 2015 | JP | national |