Augmented reality glasses

This application claims the priority benefit of Taiwan application serial no. 109131884, filed on Sep. 16, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

1. Field of the Invention

The invention relates to an optical apparatus, and in particular, to augmented reality glasses.

2. Description of Related Art

With the advancement of display technologies, an augmented reality display technology gradually becomes popular and is widely used in people's life. The augmented reality technology enables human eyes to simultaneously see a real object and a virtual image, and the virtual image can interact with the real object.

However, further efforts are still required for the current augmented reality technology. For example, the human eyes cannot focus on the virtual image and the real object simultaneously during interaction, and the virtual image itself may even exhibit a vergence-accommodation conflict (VAC). Specifically, when image light provided by a virtual reality apparatus enters the eyes, the left and right eyes respectively focus on a virtual imaging position seen by the left eye and a virtual imaging position seen by the right eye. However, the brain construes the position at which direct sights of the two eyes intersect as the image position. When the focus positions of the two eyes are different from the position at which the direct sights of the two eyes intersect, the human brain may be confused, and such confusion may easily result in dizziness. Such phenomenon is referred to as a VAC phenomenon.

In addition, since the augmented reality technology is related to near-to-eye display optics, if a visible range (i.e., an eye box) is less than a pupil of the eye, the image perceived by the eye may be distorted, incorrectly rendered, or even no content of the image is displayed. Therefore, how to provide a sufficient visible range while taking into account field of view is also an issue to work on.

The invention provides augmented reality glasses which induces no vergence-accommodation conflict and has a sufficient visible range and a field of view.

An embodiment of the invention provides augmented reality glasses adapted to be worn in front of an eye of a user. The augmented reality glasses include at least one image source and a plurality of reflecting mirrors. The at least one image source is configured to provide at least one image beam to the eye, where the at least one image beam has a plurality of sub-beams. The plurality of reflecting mirrors are disposed on a path of the at least one image beam to respectively reflect the sub-beams. The at least one image beam has at least one first width before being incident on the reflecting mirrors and has at least one second width after being reflected by the reflecting mirrors. The at least one second width is greater than the at least one first width.

Based on the above, the augmented reality glasses provided in the embodiments of the invention reflect the image beam through the plurality of reflecting mirrors. Since the reflecting mirrors may generate a large depth of field, a large focusing range is provided for a virtual image. Therefore, a vergence-accommodation conflict can be avoided. In addition, the image beam has a larger width after being reflected by the reflecting mirrors. As a result, the visible range is increased.

In order to make the above features and advantages of the invention more comprehensible, a detailed description is made below with reference to the accompanying drawings by using embodiments.

FIG. 1A is a schematic diagram of a visual behavior of human eyes.

FIG. 1B is a schematic diagram of lens imaging and pinhole imaging.

FIG. 2 , FIG. 3A , FIG. 3B , and FIG. 4 are each a schematic diagram of augmented reality glasses according to an embodiment of the invention.

FIG. 5 and FIG. 6 are each a schematic diagram of a part of a structure of augmented reality glasses according to an embodiment of the invention.

FIG. 7 is a schematic plan view of a part of a structure of augmented reality glasses according to an embodiment of the invention.

Referring to FIG. 1A , FIG. 1A is a schematic diagram of a visual behavior of human eyes. In FIG. 1A , similar to working principles of augmented reality glasses, an image source provides image beams to eyes EY 1 and EY 2 respectively. It should be noted herein that for clarity of description, the image source and the image beams incident on the eyes are not shown in FIG. 1A , and only an optical path corresponding to a virtual image generated by the image beam is shown. In this example, the image beam causes the eyes EY 1 and EY 2 to verge at a position VP 1 (that is, the position VP 1 at which direct sights of the eyes EY 1 and EY 2 intersect), and causes a user's brain to consider that an image is seen at the position VP 1 . However, the eyes EY 1 and EY 2 focus on positions IG 1 and IG 2 , respectively. It may be learned that respective monocular focusing distances AD 1 of the eyes EY 1 and EY 2 are different from a binocular vergence distance VD 1 . Because the monocular focusing distance AD 1 does not match the binocular vergence distance VD 1 , which violates a normal visual physiological mechanism, confusion in the human brain may be caused, and dizziness may be easily generated, that is, a vergence-accommodation conflict is caused.

In order to relieve the above vergence-accommodation conflict, referring to FIG. 1B , FIG. 1B is a schematic diagram of lens imaging and pinhole imaging. In FIG. 1B , the image source provides an image beam IN 1 . When passing through a lens L 1 for imaging, the image beam IN 1 has a depth of field DOF 1 . When passing through a pinhole PH 1 for imaging, the image beam IN 1 has a depth of field DOF 2 . It may be learned that the depth of field DOF 2 for pinhole imaging is larger than the depth of field DOF 1 for lens imaging. Specifically, a pinhole effect may be used to increase the depth of field. Therefore, for the vergence-accommodation conflict shown in FIG. 1A , the pinhole effect may be used to increase the depth of field and a focusing range of the eyes, so as to cause the eyes to verge within a range of the depth of field, thereby avoiding the vergence-accommodation conflict.

Referring to FIG. 2 , FIG. 2 is a schematic diagram of augmented reality glasses according to an embodiment of the invention. Augmented reality glasses 100 are adapted to be worn in front of an eye EY of a user. The augmented reality glasses 100 include an image source 110 and a plurality of reflecting mirrors 121 - 123 . The image source 110 provides an image beam 1101 . The image beam 1101 has a plurality of sub-beams 131 - 133 . The image beam 1101 travels toward the eye EY after being reflected by the reflecting mirrors 121 - 123 . The reflecting mirror 121 reflects the sub-beam 131 , the reflecting mirror 122 reflects the sub-beam 132 , and the reflecting mirror 123 reflects the sub-beam 133 . The image beam 1101 has a first width W 11 before being incident on the plurality of reflecting mirrors 121 - 123 , and has a second width W 12 after being reflected by the plurality of reflecting mirrors 121 - 123 . The second width W 12 is greater than the first width W 11 . Specifically, by appropriately arranging positions and orientations of the image source 110 and the plurality of reflecting mirrors 121 - 123 , a width of the image beam 1101 may be increased from the first width W 11 to the second width W 12 , thereby providing a sufficient visible range.

It should be noted that the eye EY may be a right eye and/or a left eye of the user. For example, the augmented reality glasses 100 provide the image beam 1101 to only the right eye or the left eye of the user, or provide the image beam 1101 to both of the right eye and the left eye of the user.

According to an embodiment of the invention, the augmented reality glasses 100 further include a light-transmitting plate 120 . The light-transmitting plate 120 includes a first surface 120 L away from the eye EY, a second surface 120 R close to the eye EY, and a third surface 120 T close to the image source 110 . The plurality of reflecting mirrors 121 - 123 are disposed on the first surface 120 L. After being reflected by the plurality of reflecting mirrors 121 - 123 , the image beam 1101 is emitted from the second surface 120 R of the light-transmitting plate 120 to be transmitted toward the eye EY of the user. According to an embodiment of the invention, the light-transmitting plate 120 may be a lens. After the eye EY receives the image beam 1101 from the second surface 120 R, the image beam 1101 is imaged on a retina, and a virtual image is sensed in front of the eye EY. In addition, light from an external object may sequentially penetrate the first surface 120 L and the second surface 120 R to be transmitted to the eye EY. In this way, the user can simultaneously see the image provided by the image source 110 and the external object, thereby achieving an effect of augmented reality.

According to an embodiment of the invention, a maximum width of each of the plurality of reflecting mirrors 121 - 123 is less than 3 mm. Therefore, each of the plurality of reflecting mirrors has a pinhole effect, so that the image beam 1101 entering the eye EY has a large depth of field. For the augmented reality glasses 100 providing the image beam 1101 to both of the right eye and the left eye of the user, the plurality of reflecting mirrors 121 - 123 with the pinhole effect reflect the image beam 1101 to the eyes of the user. A virtual image generated by the image beam 1101 has a large depth of field, and the eyes can verge at a position within a range of the depth of field, thereby avoiding a vergence-accommodation conflict. In some embodiments, some of the plurality of reflecting mirrors 121 - 123 may be curved reflecting mirrors with a pinhole effect.

According to an embodiment of the invention, the image source 110 of the augmented reality glasses 100 may be a display panel, and a display surface of the display panel provides the image beam 1101 . An included angle θ exists between the display surface of the display panel and the third surface 120 T of the light-transmitting plate 120 . The included angle θ may be greater than or equal to zero degrees. By changing the angle θ, angles at which the plurality of sub-beams 131 - 133 are incident on the plurality of reflecting mirrors 121 - 123 may be changed, thereby changing directions in which the plurality of sub-beams 131 - 133 travel after being reflected by the plurality of reflecting mirrors 121 - 123 and changing the second width W 12 . It should be noted that the image source 110 of the augmented reality glasses 100 is not limited to the display panel. In some embodiments, the image source 110 may be a projector.

Referring to FIG. 3A and FIG. 3B , FIG. 3A and FIG. 3B are each a schematic diagram of augmented reality glasses according to an embodiment of the invention. In FIG. 3A , augmented reality glasses 200 include an image source 110 , a light-transmitting plate 220 , and a plurality of reflecting mirrors 121 - 126 . The light-transmitting plate 220 has a first surface 220 L, a second surface 220 R, and a third surface 220 T. The image source 110 provides an image beam 1101 . The image beam 1101 has a plurality of sub-beams 131 - 136 . The plurality of sub-beams 131 - 136 enter the light-transmitting plate 220 from the third surface 220 T of the light-transmitting plate 220 . The plurality of reflecting mirrors 121 - 126 are disposed on the first surface 220 L of the light-transmitting plate 220 , and angles at which the plurality of sub-beams 131 - 136 are respectively incident on the plurality of reflecting mirrors 121 - 126 are different from each other. The reflecting mirror 121 reflects the sub-beam 131 , the reflecting mirror 122 reflects the sub-beam 132 , the reflecting mirror 123 reflects the sub-beam 133 , the reflecting mirror 124 reflects the sub-beam 134 , the reflecting mirror 125 reflects the sub-beam 135 , and the reflecting mirror 126 reflects the sub-beam 136 . After being reflected by the plurality of reflecting mirrors 121 - 126 , the plurality of sub-beams 131 - 136 are emitted out of the light-transmitting plate 220 via the second surface 220 R of the light-transmitting plate 220 and travel toward an eye EY. The image beam 1101 has a first width W 21 before being incident on the plurality of reflecting mirrors 121 - 126 , and has a second width W 22 after being reflected by the plurality of reflecting mirrors 121 - 126 . The second width W 22 is greater than the first width W 21 . Specifically, by appropriately arranging positions and orientations of the image source 110 and the plurality of reflecting mirrors 121 - 126 , a width of the image beam 1101 may be increased from the first width W 21 to the second width W 22 , thereby providing a sufficient visible range, that is, extending an eye box.

In comparison to the augmented reality glasses 200 in FIG. 3A , in FIG. 3B , augmented reality glasses 300 also include an image source 110 , a light-transmitting plate 320 , and a plurality of reflecting mirrors 121 - 126 . The light-transmitting plate 320 has a first surface 320 L, a second surface 320 R, and a third surface 320 T. The image beam 1101 enters the light-transmitting plate 320 from the third surface 320 T of the light-transmitting plate 320 . After being respectively reflected by the reflecting mirrors 121 - 126 , the plurality of sub-beams 131 - 136 of the image beam 1101 are emitted out of the light-transmitting plate 320 via the second surface 320 R of the light-transmitting plate 320 and travel toward the eye EY. A difference between the augmented reality glasses shown in FIG. 3B and FIG. 3A is that orientations of the plurality of reflecting mirrors 121 - 126 in the light-transmitting plate 320 are different from orientations of the plurality of reflecting mirrors 121 - 126 in the light-transmitting plate 220 . Specifically, in comparison to the plurality of reflecting mirrors 121 - 126 in FIG. 3A , normal lines of the plurality of reflecting mirrors 121 - 126 in FIG. 3B are not parallel to each other, and the plurality of sub-beams 131 - 136 incident on the eye EY provide a larger field of view. In other words, by changing the orientations of the plurality of reflecting mirrors 121 - 126 , the field of view of the eye EY is increased.

Specifically, when the light-transmitting plate (for example, a lens) of the augmented reality glasses has a fixed size, a larger visible range indicates a smaller field of view. Oppositely, a smaller visible range indicates a larger field of view. However, according to the example of the present embodiment, the plurality of reflecting mirrors 121 - 126 are disposed in the light-transmitting plate 320 of the augmented reality glasses 300 , and the orientations of the plurality of reflecting mirrors 121 - 126 are appropriately configured, so that the augmented reality glasses 300 may have a good visible range and a good field of view.

Referring to FIG. 4 , FIG. 4 is a schematic diagram of augmented reality glasses according to an embodiment of the invention. Augmented reality glasses 400 include a first image source 111 , a second image source 112 , a light-transmitting plate 420 , and a plurality of reflecting mirrors 121 - 126 . The light-transmitting plate 420 includes a first surface 420 L, a second surface 420 R, and a prism 420 P. The prism 420 P has a first surface 420 P 1 and a second surface 420 P 2 . The plurality of reflecting mirrors 121 - 126 are disposed on a first surface 420 L of the light-transmitting plate 420 . The first image source 111 provides an image beam 1111 , and the image beam 1111 is incident on the plurality of reflecting mirrors 121 - 123 from the first surface 420 P 1 of the prism 420 P. The second image source 112 provides an image beam 1121 . After being incident on the light-transmitting plate 420 from the second surface 420 P 2 of the prism 420 P, the image beam 1121 is reflected (for example, completely reflected) on the second surface 420 R of the light-transmitting plate 420 , then incident on the plurality of reflecting mirrors 124 , 125 , and 126 , and then reflected by the plurality of reflecting mirrors 124 - 126 . Specifically, the image beam 1111 has a plurality of sub-beams 141 - 143 , and the image beam 1121 has a plurality of sub-beams 151 - 153 . The sub-beam 141 is reflected by the reflecting mirror 121 , the sub-beam 142 is reflected by the reflecting mirror 122 , and the sub-beam 143 is reflected by the reflecting mirror 123 . After being reflected on the second surface 420 R of the light-transmitting plate 420 , the sub-beam 151 is reflected by the reflecting mirror 124 . After being reflected on the second surface 420 R of the light-transmitting plate 420 , the sub-beam 152 is reflected by the reflecting mirror 125 . After being reflected on the second surface 420 R of the light-transmitting plate 420 , the sub-beam 153 is reflected by the reflecting mirror 126 . Then the plurality of sub-beams 141 - 143 and the plurality of sub-beams 151 - 153 are emitted from the second surface 420 R of the light-transmitting plate 420 and travel toward the eye EY. In some embodiments, the plurality of sub-beams 151 - 153 are completely reflected on the second surface 420 R of the light-transmitting plate 420 , and then are respectively incident on the plurality of reflecting mirrors 124 - 126 .

It should be noted that an included angle between a normal line of the first surface 420 P 1 of the prism 420 P and a normal line of the second surface 420 R of the light-transmitting plate 420 is different from an included angle between a normal line of the second surface 420 P 2 of the prism 420 P and a normal line of the second surface 420 R of the light-transmitting plate 420 . The image beam 1111 has a width W 41 before being incident on the first surface 420 P 1 of the prism 420 P, and the image beam 1121 has a width W 42 before being incident on the second surface 420 P 2 of the prism 420 P. With the above arrangement relationship between the first surface 420 P 1 of the prism 420 P, the second surface 420 P 2 of the prism 420 P, and the second surface 420 R of the light-transmitting plate 420 , and through appropriate configuration of the positions and the orientations of the plurality of reflecting mirrors 121 - 126 , a total width W 43 of the image beam 1111 and the image beam 1121 emitted from the second surface 420 R of the light-transmitting plate 420 is greater than the width W 41 and the width W 42 , thereby providing a good visible range. In some embodiments, the orientations of the plurality of reflecting mirrors 121 - 126 of the augmented reality glasses 400 may be further changed, so that normal lines of some of the plurality of reflecting mirrors 121 - 126 are not parallel to each other, thereby obtaining both a good visible range and a good field of view.

Next, referring to FIG. 5 and FIG. 6 , FIG. 5 and FIG. 6 are each a schematic diagram of a part of a structure of augmented reality glasses according to an embodiment of the invention. In FIG. 5 , an image beam 1131 emitted from an image source (not shown) enters a light-transmitting plate 520 . It should be noted that, for description, FIG. 5 illustrates only a part of a structure of the light-transmitting plate 520 , and other structures of the light-transmitting plate 520 are omitted, to avoid blurring an understanding focus.

The light-transmitting plate 520 has a first surface 520 L, a second surface 520 R, and a third surface 520 T. The third surface 520 T of the light-transmitting plate 520 is a curved surface, which may be considered as an implementation of the third surface 120 T of the light-transmitting plate 120 , the third surface 220 T of the light-transmitting plate 220 , and the third surface 320 T of the light-transmitting plate 320 in the above embodiments.

Since the third surface 520 T is a curved surface, and the image beam 1131 is refracted (from a thin medium to a dense medium) on the third surface 520 T, it may be learned that the image beam 1131 has a width W 51 before penetrating the third surface 520 T, and has a width W 52 after penetrating the third surface 520 T and entering the light-transmitting plate 520 . The width W 52 is greater than the width W 51 . In addition, the image beam 1131 has a larger divergence angle after penetrating the third surface 520 T than before penetrating the third surface 520 T.

Since the image beam 1131 has a larger divergence angle after penetrating the third surface 520 T, the plurality of sub-beams of the image beam 1131 can be respectively incident on the plurality of reflecting mirrors (not shown) disposed on, for example, the first surface 520 L of the light-transmitting plate 520 , achieving the effects of avoiding a vergence-accommodation conflict and providing a good visible range and a good field of view, and the like in the above embodiments. For detailed descriptions of the reflection of the image beam on the plurality of reflecting mirrors, reference may be made to the detailed descriptions of the above embodiments, and the descriptions thereof are omitted herein.

In FIG. 6 , an image beam 1141 emitted from an image source (not shown) enters a light-transmitting plate 620 . The light-transmitting plate 620 has a first surface 620 L, a second surface 620 R, and a third surface 620 T. The third surface 620 T of the light-transmitting plate 620 has a microstructure 620 M, and the third surface 620 T may be considered as an implementation of the third surface 120 T of the light-transmitting plate 120 , the third surface 220 T of the light-transmitting plate 220 , and the third surface 320 T of the light-transmitting plate 320 in the above embodiments.

In the present embodiment, a cross section of the microstructure 620 M has a plurality of triangles, but the invention is not limited thereto. The cross section of the microstructure 620 M may have other shapes other than the triangle. The microstructure 620 M is disposed such that a width W 62 of the image beam 1141 after penetrating the third surface 620 T is greater than a width W 61 of the image beam 1141 before penetrating the third surface 620 T. In addition, the image beam 1141 has a larger divergence angle after penetrating the third surface 620 T than before penetrating the third surface 620 T.

Since the image beam 1141 has a larger divergence angle after penetrating the third surface 620 T, the plurality of sub-beams of the image beam 1141 can be respectively incident on the plurality of reflecting mirrors (not shown) disposed on, for example, the first surface 620 L of the light-transmitting plate 620 , achieving the effects of avoiding a vergence-accommodation conflict and providing a good visible range and a good field of view, and the like in the above embodiments. For detailed descriptions of the reflection of the image beam on the plurality of reflecting mirrors, reference may be made to the detailed descriptions of the above embodiments, and the descriptions thereof are omitted herein.

Next, referring to FIG. 7 , FIG. 7 is a schematic plan view of a part of a structure of augmented reality glasses according to an embodiment of the invention. Augmented reality glasses 700 include light-transmitting plates 720 PR and 720 PL respectively disposed corresponding to a right eye EY 11 and a left eye EY 12 of a user. Specifically, the augmented reality glasses 700 further include an image source (not shown) to provide an image beam. The image beam enters the right eye EY 11 through reflection by a plurality of reflecting mirrors 721 R on the light-transmitting plate 720 PR, and enters the left eye EY 12 through reflection by a plurality of reflecting mirrors 721 L on the light-transmitting plate 720 PL. The plurality of reflecting mirrors 721 R are disposed in a first reflecting mirror configuration area 721 RA in a two-dimensional manner, and the plurality of reflecting mirrors 721 L are disposed in a second reflecting mirror configuration area 721 LA in a two-dimensional manner, to optimize visible ranges and fields of view in both a vertical direction and a horizontal direction.

The first reflecting mirror configuration area 721 RA and the second reflecting mirror configuration area 721 LA both have a long side LS 1 and a short side LS 2 . The long side LS 1 is parallel to a direction of a connecting line of the right eye EY 11 and the left eye EY 12 of the user, and the short side LS 2 is perpendicular to the direction of the connecting line of the right eye EY 11 and left eye EY 12 of the user. The long side LS 1 is greater than 20 mm, and the short side LS 2 is greater than 12 mm, to ensure that the visible ranges are greater than a size of a pupil in both of the horizontal direction and the vertical direction.

Based on the above, the augmented reality glasses provided in the embodiments of the invention reflect the image beam through the plurality of reflecting mirrors. Since the reflecting mirrors have a large depth of field, a large focusing range is provided for a virtual image. Therefore, a vergence-accommodation conflict can be avoided. In addition, the image beam has a larger width after being reflected by the reflecting mirrors, increasing the visible range. Optionally, the field of view may also be increased by adjusting orientations of the reflecting mirrors, so that the augmented reality glasses may avoid the vergence-accommodation conflict and provide a favorable visible range and a favorable field of view.