CN108873327A - Head-mounted display device - Google Patents

Abstract

A head-mounted display device includes a display, a first waveguide element, and a second waveguide element. The image beam is projected to a projection target. The first waveguide element includes a plurality of first light splitting elements. The image light beam from the display enters the first waveguide element through the first light incident surface. The image beam converges within the first waveguide element to the first diaphragm. The image beam leaves the first waveguide element through the first light-emitting surface. The first diaphragm is located within the first waveguide element. The second waveguide element includes a plurality of second light splitting elements. The image light beam from the first waveguide element enters the second waveguide element through the second light incident surface. The image light beam leaves the second waveguide element through the second light-emitting surface and is projected to the second diaphragm outside the second waveguide element. The second diaphragm is located at the projection target.

Description

Head Mounted Display

technical field

The present invention relates to a display device, and in particular to a head-mounted display device.

Background technique

Near Eye Display (NED) and Head-mounted Display (HMD) are currently the next-generation killer products with great production potential. In terms of related applications of near-eye display technology, it can be divided into augmented reality (Augmented Reality, AR) technology and virtual reality (Virtual Reality, VR) technology. For augmented reality technology, relevant developers are currently working on how to provide the best image quality on the premise of being thin and light.

In the optical structure of the head-mounted display to realize the augmented reality, the image beam used for display is sent out from the projection device, and enters the user's eyes through the waveguide. The image from the light valve and the external ambient light beam enter the user's eyes through the waveguide to achieve the effect of augmented reality. In the current head-mounted display products, because the distance between the waveguide and the optical-mechanical mechanism is too close, the ambient light beam is blocked from entering the field of view of the eyes, which destroys the sense of immersion and greatly reduces the effect of augmented reality.

Nowadays, the requirements for head-mounted display devices are expected to be closer to the design of general myopia glasses or sunglasses. Therefore, how to move the huge optical machine out of the user's visual area without blocking the user's line of sight, that is, is one of the most important issues at present. In addition, the viewing angle and volume that the head-mounted display can provide are also important factors that affect user experience.

The paragraph "Background Technology" is only used to help understand the content of the present invention, so the content disclosed in the paragraph "Background Technology" may contain some known technologies that do not constitute the knowledge of those skilled in the art. The content disclosed in the "Background Technology" paragraph does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those skilled in the art before the application of the present invention.

Contents of the invention

The invention provides a head-mounted display device, which can provide a large viewing angle and good display quality, and has a small volume.

Other purposes and advantages of the present invention can be further understood from the technical characteristics disclosed in the present invention.

In order to achieve one or part or all of the above objectives or other objectives, an embodiment of the present invention provides a head-mounted display device. The head-mounted display device includes a display, a first waveguide element and a second waveguide element. The display is used to provide an image beam. The image beam is projected to the projection target. The first waveguide element includes a first light incident surface, a first light exit surface and a plurality of first light splitting elements. The image light beam from the display enters the first waveguide element through the first incident surface. The image light beam converges to the first light bar within the first waveguide element. The image light beam leaves the first waveguide element through the first light exit surface. The first stop is located within the first waveguide element. The second waveguide element is connected to the first waveguide element. The second waveguide element includes a second light incident surface, a second light exit surface and a plurality of second light splitting elements. The image light beam from the first waveguide element enters the second waveguide element through the second incident surface. The image beam leaves the second waveguide element through the second light-emitting surface, and the image beam projects outside the second waveguide element to the second diaphragm. The second light barrier is located where the target is projected.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic perspective view of a head-mounted display device according to an embodiment of the present invention.

FIG. 2A is a schematic side view of the head-mounted display device shown in FIG. 1 .

FIG. 2B is a schematic side view of the light path of the head-mounted display device of the embodiment shown in FIG. 2A of the present invention.

FIG. 2C is a schematic side view of another head-mounted display device of FIG. 1 .

FIG. 3 is a three-dimensional schematic diagram of a head-mounted display device according to another embodiment of the present invention.

FIG. 4 is a schematic perspective view of a head-mounted display device according to another embodiment of the present invention.

FIG. 5A is a schematic diagram of an embodiment of the head-mounted display device of the present invention.

FIG. 5B is a schematic diagram of an embodiment of the head-mounted display device of the present invention.

FIG. 5C is a schematic diagram of an embodiment of the head-mounted display device of the present invention.

FIG. 6A is a schematic diagram of a head-mounted display device according to another embodiment of the present invention.

FIG. 6B is a schematic diagram of a head-mounted display device according to another embodiment of the present invention.

FIG. 7 is a schematic top view of the second waveguide element in FIG. 1 .

FIG. 8 is a schematic diagram showing the reflectance distribution curve of the reflectance of the diffusion coating with respect to the incident angle of the image beam according to an embodiment of the present invention.

FIG. 9 is a schematic diagram of an image frame generated by the image beam projected on the target in the embodiment of FIG. 7 .

FIG. 10 is a schematic side view of the first waveguide element in FIG. 1 .

FIG. 11 is a schematic diagram of an image frame generated by the image beam projected on the target in the embodiment of FIG. 10 .

FIG. 12A is a schematic diagram of an image frame generated by superimposing the image beams in FIG. 9 and FIG. 11 at the projected target.

FIG. 12B is a schematic diagram of different second light splitting elements reflecting the image beam to the projection target.

FIG. 13 shows a schematic diagram of an image beam entering the second waveguide element from the first light splitting element according to an embodiment of the present invention.

FIG. 14A is a schematic diagram of an image beam entering a first light splitting element according to an embodiment of the present invention.

FIG. 14B is a schematic diagram of another embodiment of the present invention where the image beam enters the first light splitting element.

FIG. 15 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

FIG. 16 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

FIG. 17 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

FIG. 18 is a schematic diagram of some components of the head-mounted display device in the embodiment of FIG. 17 .

FIG. 19 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

FIG. 20 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

FIG. 21 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention.

Detailed ways

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of an embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referring to the directions of the drawings. Accordingly, the directional terms are used to illustrate and not to limit the invention.

FIG. 1 is a schematic perspective view of a head-mounted display device according to an embodiment of the present invention. FIG. 2A is a schematic side view of the head-mounted display device shown in FIG. 1 . Please refer to FIG. 1 and FIG. 2A , the head-mounted display device 100 of this embodiment includes a first waveguide element 110 , a second waveguide element 120 , a display 130 and a lens module 140 . The second waveguide element 120 is connected to the first waveguide element 110 . The lens module 140 is disposed between the display 130 and the first waveguide element 110 .

In this embodiment, the first waveguide element 110 includes a first light incident surface S11 , a first light exit surface S12 and a plurality of first light splitting elements Y1 , Y2 , Y3 , and Y4 . The first light splitting elements Y1, Y2, Y3, Y4 are arranged along the first direction Y. In this embodiment, the first light-incident surface S11 is disposed opposite to the first light-exit surface S12 , but the present invention is not limited thereto. In an embodiment, according to different installation positions of the display 130 , the first light incident surface S11 may also be adjacent to the first light output surface S12 . In this embodiment, the image light beam ML has an optical effect of half-transmission and half-reflection at the positions of the first light-splitting elements Y1, Y2, Y3, and Y4. The first light-splitting elements Y1, Y2, Y3, and Y4 are, for example, half-transmission Reflective film (See Through Mirror, STM). In this embodiment, the second waveguide element 120 includes a second light incident surface S21, a second light exit surface S22 and a plurality of second light splitting elements X1, X2, X3, X4, X5, X6, wherein the second light incident surface S21 , The second light-emitting surface S22 belongs to the same surface, the difference is that the second light-incident surface S21 of the second waveguide element 120 faces the first light-emitting surface S12 of the first waveguide element 110 . The second light splitting elements X1, X2, X3, X4, X5, X6 are arranged along the second direction X. In this embodiment, the optical effect of semi-transmission and semi-reflection occurs at the positions of the second light splitting elements X1 , X2 , X3 , X4 , X5 , and X6 of the image light beam ML. In this embodiment, the number of light-splitting elements included in each waveguide element and the distance between adjacent light-splitting elements can be designed according to different product requirements, and are not intended to limit the present invention. Moreover, the number of the first light splitting elements may be the same as or different from that of the second light splitting elements, and the distance between adjacent light splitting elements may be the same or different. In this embodiment, the display 130 is used to convert the illumination beam from the illumination system into the image beam ML to provide the image beam ML to the lens module 140 , wherein the illumination system will be described in detail below. In this embodiment, the display 130 includes, for example, a digital light processing (Digital Light Processing ^TM , DLP ^TM for short) projection system, a liquid-crystal display (LCD for short) projection system, or a Liquid Crystal On Silicon (Liquid Crystal On Silicon for short) projection system. LCoS) projection system and other image projection systems, but the present invention is not limited. In this embodiment, the lens module 140 is, for example, one or more lenses, and the number is not limited, depending on the design. The lens module 140 has an optical axis A1 extending in the third direction Z. The image beam ML is transmitted along the third direction Z in the lens module 140 . The image light beam ML from the display 130 passes through the lens module 140 and enters the first waveguide element 110 through the first incident surface S11 . In this embodiment, the image light beam ML passes through the first light splitting element Y1 in the first waveguide element 110 and passes along the first direction Y, and the image light beam ML is reflected by the first light splitting elements Y1, Y2, Y3, and Y4. After the action of the third direction Z (-Z), it leaves the first waveguide element 110 through the first light-emitting surface S12. It is worth noting that the first light-splitting elements Y1, Y2, Y3, and Y4 are semi-transparent The semi-reflective film, that is, part of the image light beam ML can be reflected by the first light splitting elements Y1, Y2, Y3, and Y4, and part of the image light beam ML penetrates the first light splitting elements Y1, Y2, Y3, and Y4. In this embodiment, the The optical path of the main image light beam ML is the focus of description.

In addition, the image light beam ML from the first waveguide element 110 enters the second waveguide element 120 through the second incident surface S21 along the opposite direction (-Z) of the third direction Z, and is reflected by the second waveguide element 120 After being reflected by the surface S23 , it passes toward the second light splitting elements X1 , X2 , X3 , X4 , X5 , and X6 of the second waveguide element 120 . In this embodiment, the image beam ML inside the second waveguide element 120 is transmitted along the second direction X, after the image beam ML is reflected by the second light splitting elements X1, X2, X3, X4, X5, and X6, The second light emitting surface S22 exits the second waveguide element 110 and is projected to the projection target P. Therefore, in this embodiment, the second light incident surface S21 and the second light exit surface S22 are the same surface of the second waveguide element 120 , but the second light exit surface S22 faces the projection target P. In this embodiment, the projection target P is, for example, one of the pupils of the user's eyes. In other embodiments, the projection target P is, for example, an image sensing device that receives the image beam ML, such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor image sensor (Complementary Metal-Oxide-Semiconductor). image sensor, CMOS image sensor).

In this embodiment, the image light beam ML transmits in the lens module 140 along a direction (−Z) opposite to the third direction Z, and the transmission direction is substantially the same as the extending direction of the optical axis A1 . In this embodiment, the projection target P has a visual axis A2, and its extending direction (third direction Z) is substantially the same as the transmission direction of the image beam ML projected into the projection target P, and is perpendicular to the first direction Y. Therefore, in FIG. 1, the visual axis A2 of the projection target P is translated to the YZ plane (reference plane) toward the first waveguide element 110, and the reference axis A3 can be marked in the first waveguide element 110, as shown in FIG. 2A .

That is to say, in this embodiment, the projection target P has a visual axis A2 perpendicular to the first direction Y, and the translation of the visual axis A2 toward the first waveguide element 110 will generate Reference axis A3. In Fig. 2A, on the reference plane YZ, on the transmission path of the illuminating light beam ML, the first stop PA1 formed by the illuminating light beam ML and the first light-splitting elements of the first light-splitting elements Y1, Y2, Y3, and Y4 The distance between the central position PC of Y1 in the first direction is D1, and the distance between the reference axis A3 and the central position PC of the first light splitting element Y1 in the first direction Y is D2. In this embodiment, the distance D1 is greater than or equal to the distance D2. The first light splitting element Y1 is part of the image beam ML entering the first waveguide element 110, and the first light splitting element that reflects the image light beam ML is also one of the first light splitting elements Y1, Y2, Y3, and Y4 closest to the lens module 140. one.

In this embodiment, the image light beam ML from the lens module 140 converges to the first diaphragm PA1 within the first waveguide element 110 . The first aperture PA1 is located inside the first waveguide element 110 . In this embodiment, the first aperture PA is the position where the image beam ML converges to the minimum beam diameter within the first waveguide element 110 , and after passing through the position of the first aperture PA, the image beam ML starts to diverge. For example, the lens module 140 can make the image beam ML incident on the first waveguide element 110 converge from the first light splitting element Y1 and reach the position where the beam diameter is the smallest at the first aperture PA1 . After the first diaphragm PA1 , the image light beam ML starts to diverge and enters the first light splitting element Y4 and is reflected to the first light emitting surface S12 . In this embodiment, the image light beam ML exits the second waveguide element 120 through the second light-emitting surface S22 and is projected to the second aperture PA2 outside the second waveguide element 120 . The second aperture PA2 is located where the object P is projected. For example, the second light-splitting elements X1, X2, X3, X4, X5, and X6 can reflect the image beam ML incident on the second waveguide element 120 to leave the second waveguide element 120 from the second light-emitting surface S22, and the image beam ML Projected to the position of the second diaphragm PA2, so that the image beam ML can be incident on the projection target P, wherein the position of the second diaphragm PA2 is substantially the same as the position of the projection target P, that is, one of the eyes of the user can see The position of the image is the position of the second diaphragm PA2.

In this embodiment, the field of view (FOV) of the lens module 140 corresponds to the field of view (FOV) of the projected object P where the image is received. In other words, in this embodiment, the angle of view in the diagonal direction where the projection target P receives the image formed by the image beam ML is substantially equal to the angle of view of the image beam ML projected by the lens module 140 . However, in other embodiments, the angle of view of the projection target P receiving the image formed by the image beam ML in the diagonal direction is smaller than the angle of view of the image beam ML projected by the lens module 140 .

The first viewing angle in the first direction Y and the second viewing angle in the second direction X can be obtained from the viewing angle in the diagonal direction of the image formed by the image light beam ML. In this embodiment, when the display 130 projects the image beam ML to display an image with a projection ratio of 16:9, the lens module 140 will project a diagonal viewing angle between about 30 degrees and 90 degrees. For example, the image beam ML with a viewing angle of 40 degrees passes through the first waveguide element 110 and the second waveguide element 120 to transmit the image beam ML to the projection target P, so that the projection target P can receive the angle of view in the diagonal direction of the image beam ML to form an image. About between 30 degrees and 90 degrees, such as 40 degrees, but not limited thereto. Those skilled in the art can calculate that the first viewing angle in the first direction Y is about 10 degrees and the second viewing angle in the second direction X is about 17 degrees based on the projection ratio of 16:9. It can be seen from the above that, through the head-mounted display device of the present invention, the angle of view (FOV) in the diagonal direction where the projection target P receives the image formed by the image light beam ML can be 30-90 degrees or more than 90 degrees. In addition, as shown in FIG. 2A, in another embodiment, the optical axis A1 of the lens module 140 is perpendicular to the first direction Y and parallel to the visual axis A2 of the projection target P, where the projection target P receives the image formed by the image light beam ML The angle of view (FOV) in the diagonal direction may be 30-50 degrees. 3, in another embodiment, the optical axis A1 of the lens module 140 is parallel to the first direction Y and perpendicular to the visual axis A2 of the projection target P, where the projection target P receives the image formed by the image light beam ML The angle of view (FOV) in the diagonal direction may be 50-90 degrees. The angle of view in the diagonal direction can be designed according to different product requirements, and is not intended to limit the present invention. The head-mounted display device 100 can provide a large viewing angle, and the volume of the head-mounted display device 100 can be reduced.

In other embodiments, after the image light beam ML projected by the lens module 140 forms the angle of view (FOV) in the diagonal direction of the image, the size of the first angle of view can be determined according to the number of first light splitting elements in the first waveguide element 110 , or it is determined according to the distance from the first light splitting element to the last light splitting element in the first waveguide element 110 , or it is determined according to the distance between two adjacent light splitting elements in the first waveguide element 110 . Similarly, the size of the second viewing angle is determined, for example, according to the number of second light-splitting elements in the second waveguide element 120, or according to the distance from the first light-splitting element to the last light-splitting element in the second waveguide element 120, Or it may be determined according to the distance between two adjacent light splitting elements in the second waveguide element 120 . However, it is worth mentioning that the size of the first viewing angle and the size of the second viewing angle generated by the adjustment of the first waveguide element 110 and the second waveguide element 120 can be less than or equal to the image beam projected by the lens module 140 The ML forms the size of the first viewing angle and the size of the second viewing angle of the image.

In addition, due to consideration of the image projection ratio that the display 130 can provide, it will affect the number of the first light-splitting element in the first waveguide element 110 and the number of the second light-splitting element in the second waveguide element 120. For example, if the projection If the ratio is 16:9, the number of the second light-splitting elements of the second waveguide element 120 is greater than the number of the first light-splitting elements of the first waveguide element 110 . However, under other design conditions, the number of the second light-splitting elements of the second waveguide element 120 may be smaller than the number of the first light-splitting elements of the first waveguide element 110 , and it is not limited thereto.

In addition, depending on the positions of the display and the lens module, in an embodiment, the first light incident surface of the first waveguide element may be adjacent to the first light output surface, and the optical axis of the lens module is parallel to the first direction. In an embodiment, the first light incident surface of the first waveguide element may be adjacent to the first light exit surface, and the optical axis of the lens module may be perpendicular to the first direction and parallel to the second direction.

FIG. 2B is a schematic side view of the light path of the head-mounted display device of the embodiment shown in FIG. 2A of the present invention. Also refer to FIG. 2B . Since the first light-splitting elements Y1, Y2, Y3, and Y4 of the first waveguide element 110 are semi-transparent and semi-reflective films, that is, part of the image light beam ML can be reflected by the first light-splitting elements Y1, Y2, Y3, and Y4, and part of the image The light beam ML penetrates the first light splitting elements Y1, Y2, Y3, and Y4. In this embodiment, part of the image light beam ML in the first waveguide element 110 converges at the position of the first diaphragm PA1. It can be known from basic optical principles that The part of the image light beam ML passing through the first light splitting element Y1 can also converge at the position of the diaphragm PA1' in the second waveguide element 120, and the distance from the center position of the first light splitting element Y1 to the position of the diaphragm PA1' is equal to the second waveguide element 120. A distance from the center position of the light splitting element Y1 to the position of the first diaphragm PA1. For the same reason, the partial image light beam ML reflected by the first light splitting elements Y2 and Y3 can converge to the positions of the diaphragms PA1 ″ and PA1 ″′ in the second waveguide element 120 , and the center position of the first light splitting element Y2 reaches the position of the diaphragm PA1 The distance from the position of "is equal to the distance from the center position of the first light-splitting element Y2 to the position of the first light barrier PA1, and the distance from the center position of the first light-splitting element Y3 to the position of the light barrier PA1"' is equal to the distance from the first light-splitting element Y3 The distance from the center position of to the position of the first diaphragm PA1.

FIG. 2C is a schematic side view of a head-mounted display device according to another embodiment of the present invention. The head-mounted display device in the embodiment of FIG. 2C is similar to the head-mounted display device 100 in the embodiment of FIG. 2A , and its components and related descriptions can refer to the components and related descriptions of the head-mounted display device 100 , which will not be repeated here. The differences between the head-mounted display device 100 and the head-mounted display device 100 are as follows. In this embodiment, the head-mounted display device 100 includes a first light waveguide element 110 and a second light waveguide element 120 . In addition, the head-mounted display device 100 further includes a reflector 150 disposed beside the first light-incident surface S11 and facing the first light-incident surface S11 . The mirror 150 is used to reflect the image beam ML provided by the display 130 through the lens module 140 , so that the image beam ML enters the first optical waveguide element 110 from the first incident surface S11 . Next, the image light beam ML entering the first optical waveguide element 110 can be reflected by a plurality of first beam splitters Y1 , Y2 , Y3 , Y4 and delivered to the second optical waveguide element 120 .

Specifically, the included angle between the reflecting mirror 150 and the first light-emitting surface S11 is, for example, 45 degrees. When the image beam ML is reflected by the mirror 150, it may enter the first beam splitter Y1. In addition, in this embodiment, the position of the first diaphragm PA1 of the image light beam ML is located in the first optical waveguide element 110 , for example. The position of the first diaphragm PA1 is, for example, located between the first light splitters Y1 , Y2 , Y3 , and Y4 . Therefore, the image light beam ML traveling through the first optical waveguide element 110 can be narrowed to the position of the first diaphragm PA1. In this embodiment, by setting the position of the first diaphragm PA1 where the image beam ML is narrowed to the inside of the first optical waveguide element 110, it is possible to prevent the image beam ML from diverging too early on the XY plane and to be in the first light exit. The surface S12 and the first incident surface S11 produce total reflection. That is to say, the image light beam ML can be guided into the second optical waveguide element 120 through the first light splitters Y1, Y2, Y3, and Y4 before total reflection occurs, so that the image light beam ML can be prevented from entering the first optical waveguide element. Total reflection occurs in 110 and causes the problem of unexpected display screen.

FIG. 3 is a three-dimensional schematic diagram of a head-mounted display device according to another embodiment of the present invention. Please refer to FIG. 1 and FIG. 3, the head-mounted display device 200 of this embodiment is similar to the head-mounted display device 100 of the embodiment of FIG. 230 is arranged parallel to the lens module 240 on the side of the first waveguide element 110. The image beam ML from the lens module 240 enters the first waveguide element 100 from the first incident surface S13 of the first waveguide element 110, and passes through the first light-emitting The face S12 leaves the first waveguide element 110 . Therefore, in this embodiment, the first light incident surface S13 of the first waveguide element 110 is adjacent to the first light exit surface S12 , and the optical axis A1 of the lens module 240 is parallel to the first direction Y. In this embodiment, the first aperture PA1 is located inside the first waveguide element 210 , and the second aperture PA2 is located where the target P is projected. Moreover, the position of the first aperture PA1 within the first waveguide element 210 also meets the condition that the distance D1 is greater than or equal to the distance D2.

FIG. 4 is a schematic perspective view of a head-mounted display device according to another embodiment of the present invention. Please refer to FIG. 1 and FIG. 4, the head-mounted display device 800 of this embodiment is similar to the head-mounted display device 100 of the embodiment of FIG. The light emitting surfaces are adjacent, and the optical axis A1 of the lens module is perpendicular to the first direction Y and parallel to the second direction X.

Specifically, in this embodiment, the head-mounted display device 800 includes a first waveguide element 810 , a second waveguide element 820 , a third waveguide element 850 , a display 830 and a lens module 840 . In one embodiment, the third waveguide element 850 and the second waveguide element 820 can also be made of the same material and integrally formed. The display 830 is used to provide the image beam ML. In this embodiment, the image beam ML is incident on the first waveguide element 810 through the first incident surface S14 , is reflected by the reflecting surface S15 , and travels toward the first direction Y. Next, the image light beam ML leaves the first waveguide element 810 through the first light exit surface S12 . Therefore, in this embodiment, the first light incident surface S14 is adjacent to the first light exit surface S12 and the reflective surface S15 , and the optical axis A1 of the lens module 840 is perpendicular to the first direction Y and parallel to the second direction X. The positions of the display 830 and the lens module 840 may be determined according to different product designs or optical characteristics, which are not limited by the present invention. Moreover, the third waveguide element 850 of this embodiment can adopt the design of the third waveguide element in one of the embodiments shown in FIG. 5A to FIG. 5C .

In this embodiment, the first waveguide element 810 includes a plurality of first light splitting elements 811 . The image light beam ML undergoes an optical effect of half-transmission and half-reflection at the positions of the first light splitting elements 811 , and enters the third waveguide element 850 . The third waveguide element 850 may have, for example, the reflective structure described in the embodiment of FIG. 5A to FIG. 5C . In this embodiment, the image light beam ML is reflected at the position of the reflective structure of the third waveguide element 850 and enters the second waveguide element 820 . The second waveguide element 820 includes a plurality of second light splitting elements 831 . The image light beam ML undergoes an optical effect of half-transmission and half-reflection at the positions of the second light splitting elements 831 , and leaves the second waveguide element 820 . In this embodiment, the image beam ML leaving the second waveguide element 820 is used to enter the projection target P, where the projection target P is, for example, the position of one eye of the user. In addition, the number of the first light-splitting element 811 and the second light-splitting element 831 is not limited to that shown in FIG. 4 , and the number of light-splitting elements arranged in the first waveguide element 810 and the second waveguide element 820 can be designed according to different product requirements. , the present invention is not limited.

In this embodiment, since the first light splitting elements 811 and the second light splitting elements 831 have coatings respectively, and the coatings can only pass through the image beam ML incident in a specific incident angle range. Therefore, when the image beam ML enters these first light splitting elements 811 and these second light splitting elements 831 at an excessively large incident angle during the traveling process of the first waveguide element 810 and the second waveguide element 820, a part of the image light beam ML instead Reflection will occur on the first light splitting elements 811 and the second light splitting elements 831 . The unexpected reflected image light beam ML will continue to travel in the first waveguide element 810 and the second waveguide element 820, and in the case of entering the beam splitter at a smaller angle, it will be obliquely introduced in the direction opposite to the aforementioned expected direction. user's eyes. At this time, in addition to watching the originally expected image frame, the user will also watch the mirrored unexpected image frame at the same time. Therefore, the user tends to feel that there is a ghost in the video screen or the video screen becomes blurred when using the head-mounted display.

FIG. 5A is a schematic diagram of an embodiment of the head-mounted display device of the present invention, refer to FIG. 5A . In this embodiment, the head-mounted display device 500 includes a first waveguide element 510 , a second waveguide element 520 and a third waveguide element 530 , wherein the second waveguide element 520 includes a plurality of second light splitting elements 531 . In this embodiment, the first waveguide element 510 is disposed beside the third waveguide element 530 . The first waveguide element 510 can be bonded to the third waveguide element 530, or bonded through a transparent adhesive, or use a fixing member 532 (such as a spacer or an adhesive material or a spacer) between the first waveguide element 510 and the third waveguide. The periphery of the element 530 is fixed, and the middle region has a gap, which may be a small air gap. In addition, the first light emitting surface ES1 faces the second light incident surface IS2. The second light incident surface IS2 is connected to the second light exit surface ES2. The third waveguide element 530 can be adhered to the second waveguide element 520, or bonded through a transparent adhesive. Therefore, the third light incident surface IS3 is connected to the second light exit surface ES2. In this embodiment, the third waveguide element 530 includes a reflective structure 521 . The reflective structure 521 may be composed of a plurality of optical microstructures, and the plurality of optical microstructures may be a plurality of obliquely arranged and periodically arranged reflective surfaces.

In addition, the purpose of the above-mentioned air gap (air gap) is that the image beam ML with a large incident angle enters the first waveguide element 510, so as to prevent part of the image beam ML from directly penetrating the first waveguide element 510, so that part of the image beam ML The light beam ML is transmitted in the first waveguide element 510 in a total reflection manner. Another advantage is that part of the image beam ML is reflected by the reflective structure 521 and then directed towards the second light incident surface IS2. Due to the air gap, the part of the image beam ML can be totally reflected on the second light incident surface IS2, and the part of the image beam ML is guided into the second light incident surface IS2. waveguide element 520 .

In this embodiment, the image light beam ML enters the third waveguide element 530 through the first light exit surface ES1 of the first waveguide element 510 , and enters the third waveguide element 530 through the second light incident surface IS2 . The image beam ML reflects the image beam ML from the second incident surface IS2 through the reflective structure 521 , and leaves the third waveguide element 530 through the second incident surface ES2 . The image beam ML enters the second waveguide element 520 through the third light incident surface IS3 and exits the second waveguide element 520 through the third light exit surface ES3.

In this embodiment, the third waveguide element 530 and the second waveguide element 520 can be made of different materials. For example, the third waveguide element 530 can be plastic material, and the first waveguide element 510 and the second waveguide element 520 can be glass, but the invention is not limited thereto. In one embodiment, the third waveguide element 530 and the second waveguide element 520 can also be made of the same material and integrally formed. In this embodiment, the material selection of the first waveguide element 510 , the third waveguide element 530 and the second waveguide element 520 can also be determined according to different reflectivity requirements or product design.

FIG. 5B is a schematic diagram of an embodiment of the head-mounted display device of the present invention, refer to FIG. 5B . In this embodiment, the head-mounted display device 600 includes a first waveguide element 610 , a third waveguide element 630 and a second waveguide element 620 , wherein the second waveguide element 620 includes a plurality of second light splitting elements 631 . In this embodiment, the first waveguide element 610 is disposed beside the second waveguide element 620 . The first waveguide element 610 can be bonded to the second waveguide element 620, or bonded through a transparent adhesive, or use mechanical components (such as spacers or adhesive materials) on the periphery of the first waveguide element 610 and the second waveguide element 620 Fixed, but with space in the middle area, which can be a tiny air gap. Therefore, on the transmission path of the image beam ML, the image beam ML passes through the second waveguide element 620 through the first light-emitting surface ES1 and is transmitted to the third waveguide element 630 . In addition, the first light emitting surface ES1 faces the second light incident surface IS2. The second light incident surface IS2 is connected to the second light exit surface ES2. The third waveguide element 630 can be adhered to the second waveguide element 620 , or bonded through a transparent adhesive. Therefore, the third light incident surface IS3 is connected to the second light exit surface ES2. The second light incident surface IS2 and the third light incident surface IS3 face the first light exit surface ES1. In this embodiment, the third waveguide element 630 includes a reflective structure 621 . The reflective structure 621 may be composed of a plurality of optical microstructures, and the plurality of optical microstructures may be a plurality of obliquely arranged and periodically arranged reflective surfaces.

In this embodiment, the image beam ML enters the second waveguide element 620 through the first light exit surface ES1 of the first waveguide element 610 , passes through the second waveguide element 620 and then enters the third waveguide element 630 through the second light incident surface IS2 . The image beam ML reflects the image beam ML from the second incident surface IS2 through the reflective structure 621 , and leaves the third waveguide element 630 through the second incident surface ES2 . The image beam ML re-enters the second waveguide element 620 through the third light-incident surface IS3 , and exits the second waveguide element 620 through the third light-emitting surface ES3 .

In this embodiment, the third waveguide element 630 and the second waveguide element 620 can be made of different materials. For example, the third waveguide element 630 can be plastic material, and the first waveguide element 610 and the second waveguide element 620 can be glass, but the invention is not limited thereto. In an embodiment, the third waveguide element 630 and the second waveguide element 620 may also be made of the same material and integrally formed. In this embodiment, the material selection of the first waveguide element 610 , the third waveguide element 630 and the second waveguide element 620 can also be determined according to different reflectivity requirements or product design.

FIG. 5C is a schematic diagram of an embodiment of the head-mounted display device of the present invention, refer to FIG. 5C . In this embodiment, the head-mounted display device 700 includes a first waveguide element 710 , a third waveguide element 730 and a second waveguide element 720 , wherein the second waveguide element 720 includes a plurality of second light splitting elements 731 . In this embodiment, the first waveguide element 710 is disposed beside the second waveguide element 720 . The first waveguide element 710 can be bonded to the second waveguide element 720, or bonded through a transparent adhesive, or use a fixing member (such as a spacer or an adhesive or a spacer, as shown in FIG. 5A ) on the first waveguide element. 710 is fixed to the periphery of the second waveguide element 720 , and there is a gap in the middle region, which can be a small air gap. Therefore, the first light emitting surface ES1 faces the second light incident surface IS2 through the second waveguide element 720 . The second light incident surface IS2 is connected to the second light exit surface ES2. The third waveguide element 730 is obliquely disposed beside the second waveguide element 720 , so the second light incident surface IS2 , the second light exit surface ES2 and the third light incident surface IS3 have an inclination angle relative to the third light exit surface ES3 . The third waveguide element 730 can be adhered to the second waveguide element 720 , or bonded through a transparent adhesive. Therefore, the third light incident surface IS3 is connected to the second light exit surface ES2. In this embodiment, the third waveguide element 730 includes a reflective structure 721 and a transparent layer. The third waveguide element 730 is a reflecting unit, and the reflecting structure 721 can be a mirror or a reflective coating.

In this embodiment, the image beam ML enters the second waveguide element 720 through the first light exit surface ES1 of the first waveguide element 710 , passes through the second waveguide element 720 and then enters the third waveguide element 730 through the second light incident surface IS2 . The image beam ML reflects the image beam ML from the second incident surface IS2 through the reflective structure 721 , and leaves the third waveguide element 730 through the second incident surface ES2 . The image beam ML re-enters the second waveguide element 720 through the third light-incident surface IS3 , and exits the second waveguide element 720 through the third light-emitting surface ES3 .

In this embodiment, the first waveguide element 710 , the third waveguide element 730 and the second waveguide element 720 can all be made of glass material, but the invention is not limited thereto. In one embodiment, the third waveguide element 730 may be a reflective unit made of plastic material. Moreover, the material selection of the first waveguide element 710 , the third waveguide element 730 , and the third waveguide element 730 can also be determined according to different reflectivity requirements or product design.

FIG. 6A is a schematic diagram of a head-mounted display device according to another embodiment of the present invention. Referring to FIGS. 1-4 and 6A , in this embodiment, the head-mounted display device 900 includes a first waveguide element 910 , a third waveguide element 930 , a second waveguide element 920 and a reflective element 950 . The reflective element 950 is used to receive the image beam ML provided by the display. The reflective element 950 can be a prism (not shown) with a reflective layer, and the image beam provided by the display enters the reflective element 950 from the X-axis direction. The reflective layer makes the image beam incident to the first waveguide element 910 along the Y-axis direction. For the convenience of description, the third waveguide element 930 of this embodiment adopts the reflective structure design of the second waveguide element in the embodiment of FIG. 5C , but the present invention is not limited thereto. The design of the reflective structure of the second waveguide element in the embodiment shown in FIG. 5A and FIG. 5B is also applicable.

In this embodiment, the present invention proposes that the image light beam ML provided by the display can only have a single polarization direction. For example, when the image light beam ML enters the first waveguide element 910 from the reflective element 950, a polarizer can be used, and the polarizer 960 can be arranged between the display and the first waveguide element 910, between the display and the reflective element 950 between the reflective element 950 and the first waveguide element 910, so that the image beam incident on the first waveguide element 910 by the display only has light in the P polarization direction (like the direction of the third axis Z), and the image beam ML enters the second waveguide element 920 from the first waveguide element 910 through the reflective structure of the third waveguide element 930. Based on the optical definition of basic polarized light in this field, it can be known that the light in the P polarization direction is converted into the light in the S polarization direction. (like the direction of the second axis Y). Therefore, in the first waveguide element 910, only the image beam with a single polarization direction is transmitted, and the coating layers of the first light splitting elements 911 and the second light splitting elements 931 can correspond to the image light beam with a single polarization direction. design.

In another embodiment, the head-mounted display device 900 of this embodiment may further include a phase delay film 970 . In this embodiment, the polarizing element 960 can be arranged between the display and the first waveguide element 910, or between the reflective element 950 and the first waveguide element 910, so that the image incident on the first waveguide element 910 by the reflective element 950 The light beam may only have light in the S polarization direction. Moreover, the phase retarder 970 can be arranged between the first waveguide element 910 and the third waveguide element 930 (the phase retarder 970 can also be arranged between the second waveguide element 920 and the first waveguide element 910), so that the The image light beam incident on the second waveguide element 920 by the first waveguide element 910 may be light in the S polarization direction. Accordingly, the head-mounted display device 900 can effectively reduce the unintended reflected light traveling in the first waveguide element 910 and the second waveguide element 920 by configuring the polarizing element 960 and the phase retarder 970 .

FIG. 6B is a schematic diagram of a head-mounted display device 900A according to another embodiment of the present invention. For this, the image light beam ML provided by the display 830 may only have a single polarization direction. For example, the image beam ML directly incident on the first waveguide element 910 may have light in the P polarization direction (like the direction of the third direction Z), and the image beam ML is incident from the first waveguide element 910 to the second waveguide element 910 through the reflective structure. The waveguide element 920 is naturally converted into the image light beam ML in the S polarization direction (like the direction of the first direction Y) based on the basic optical reflection effect. Therefore, only the image light beam ML with a single polarization direction can be transmitted in the first waveguide element 910, and the individual coatings of the first light splitting elements 911 and the second light splitting elements 931 can be designed corresponding to the image light beam ML with a single polarization direction. Of. Accordingly, the head-mounted display device 900A of this embodiment can effectively reduce the unintended reflected light traveling in the first waveguide element 910 and the second waveguide element 920 . In this embodiment, the first aperture PA2 is also located inside the first waveguide element 910 , and the second aperture PA2 is located where the target P is projected. Moreover, the position of the first light barrier within the first waveguide element 910 also meets the condition that the distance D1 is greater than or equal to the distance D2.

FIG. 7 is a schematic top view of the second waveguide element in FIG. 1 . FIG. 8 is a schematic diagram showing the reflectance distribution curve of the reflectance of the diffusion coating with respect to the incident angle of the image beam according to an embodiment of the present invention. In FIG. 8 , the reflectance distribution curve of the reflectance of the diffusion coating relative to the incident angle of the image beam is, for example, taken with a wavelength of 520 nm as an example, but it is not intended to limit the present invention. Moreover, the reflectance distribution curve in FIG. 8 is only used for illustration, and is not intended to limit the present invention. Please refer to FIG. 7 to FIG. 8. In this embodiment, each of the second light splitting elements X1, X2, X3, X4, X5, and X6 in the second waveguide element 120 includes a first surface and an angle relative to the first surface. The second surface, and one of the first surface and the second surface may include a diffusion coating, taking the first surface including a diffusion coating as an example. Taking the second light splitting element X1 as an example, the second surface SX12 is opposite to the first surface SX11, and the first surface SX11 includes a diffusion coating. In this embodiment, the image light beam ML enters each second light splitting element from the first surface of each second light splitting element, and the incident angle range of the image light beam ML incident on each second light splitting element is between 15 degrees and 45 degrees. , so that part of the image light beam ML can be reflected to the pupil P through the diffusion coating, wherein the angle between each second light splitting element in the second waveguide element 120 and the second light-emitting surface S22 is 30 degrees, but this case does not limit. In the second waveguide element 120 , the polarization direction of the image light beam ML is the second polarization direction (for example, S-direction polarized light). In this embodiment, the reflectance of the diffusion coating conforms to the reflectance distribution curve of FIG. 8 , for example. When the incident angle is between 15 degrees and 45 degrees, the reflectance of the Nth second light splitting element is less than or equal to the reflectance of the (N+1)th second light splitting element, where N is an integer greater than or equal to 1 . In FIG. 8 , the curve SR(N+1) is, for example, the reflectance distribution curve of the (N+1)th second light splitting element, and the curve SRN is, for example, the reflectance distribution curve of the Nth second light splitting element. For example, the reflectivity of the first second light-splitting element X1 is less than or equal to the reflectivity of the second second light-splitting element X2, but not limited thereto.

FIG. 9 is a schematic diagram of an image frame generated by the image beam projected on the target in the embodiment of FIG. 7 . Please refer to FIG. 7 to FIG. 9 , in this embodiment, the image frame formed in the projection target P is the image light beam ML reflected from each second light splitting element, in other words, the horizontal direction ( The image frame of the second direction X). Therefore, the image frames generated by the image light beams ML reflected by different second light splitting elements on the projection target P will partially overlap or be partially connected. If there is a gap between the image frames, the human eye will see an image has a black area. Therefore, as shown in FIG. 9 , for example, different blocks of the image frame in the projection target P are contributed by the image light beam ML reflected by different second light splitting elements, and image overlapping or image overlap occurs in some blocks. connect. According to the design method of the diffusion coating in this embodiment, that is, the reflectance of the Nth second light splitting element among the second light splitting elements is less than or equal to the (N+1)th second light splitting element among the second light splitting elements, Even if some blocks are overlapped, the image frame in the projection target P can still maintain uniformity and have good display quality.

FIG. 10 is a schematic side view of the first waveguide element in FIG. 1 . Please refer to FIG. 10 , in this embodiment, each of the first light splitting elements Y1 , Y2 , Y3 , and Y4 includes a first surface and a second surface opposite to the first surface, and the first surface includes a diffusion coating. And one of the first surface and the second surface may include a diffusion coating, taking the first light splitting element Y1 as an example, the second surface SY22 is opposite to the first surface SY21, and the first surface SY21 includes a diffusion coating. In this embodiment, referring to FIG. 3 at the same time, the optical axis A1 of the lens module 140 is parallel to the first direction Y and perpendicular to the visual axis A2 of the projection target P, and the image beam ML is incident on the first surface SY21 of the first light splitting element Y1, which The incident angle is between 30 degrees and 60 degrees, wherein the angle between each first light-splitting element in the first waveguide element 110 and the first light-emitting surface S12 is 45 degrees, and it can also be 30 degrees under other designs, But this case is not limited to this. In addition, the reflectance of the M-th first light-splitting element is less than or equal to the reflectance of the (M+1)-th first light-splitting element, where M is an integer greater than or equal to 1. For example, the reflectance of the second first light-splitting element Y2 is less than or equal to the reflectance of the third first light-splitting element Y3, so that part of the image beam ML can be reflected to the second waveguide element 120 through the diffusion coating, and then projected The video frame in the object P can still be kept uniform and has good display quality. In another embodiment, referring to FIG. 2A at the same time, the optical axis A1 of the lens module 140 is perpendicular to the first direction Y and parallel to the visual axis A2 of the projection target P, and the image beam ML is incident on the first surface SY21,1 of the first light splitting element. Subtracting the reflectance of the first first light-splitting element is less than or equal to the reflectance of the (M+1)th first light-splitting element, where M is an integer greater than or equal to 1. For example, 1 minus the reflectance of the first first light-splitting element Y1 is less than or equal to the reflectance of the second first light-splitting element Y2 . In this way, part of the image light beam ML can be reflected to the second waveguide element 120 through the diffusion coating, and the image frame in the projection target P can still be kept uniform with good display quality.

FIG. 11 is a schematic diagram of an image frame generated by the image beam projected on the target in the embodiment of FIG. 10 . Please refer to FIG. 10 and FIG. 11 , in this embodiment, the image frame formed in the projection target P is the image light beam ML reflected from each first light splitting element. In other words, the image frames in the vertical direction (the first direction Y) can be seen by human eyes. The image beams ML reflected by different first light-splitting elements on the projection target P partially overlap or partially connect the image frames, that is, the image light beams ML reflected by different second light-splitting elements generate on the projection target P An image frame, the image frame is formed by partially overlapping image light beams ML, or the image light beams ML reflected by different second light splitting elements generate an image frame on the projection target P, and the image frame is formed by partially contiguous image light beams ML form.

In other embodiments, the image beam ML reflected by different first light splitting elements and the image light beam ML reflected by different second light splitting elements generate an image frame on the projection target P, and the image frame consists of partially overlapping image beams ML formed. Or in another embodiment, the image light beam ML reflected by different first light-splitting elements and the image light beam ML reflected by different second light-splitting elements generate an image frame on the projection target P, and the image frame is composed of partially connected Image beams are formed. If there is a gap between the image frames, the human eyes will see that an image has a black area. Therefore, as shown in FIG. 11 , different blocks of the image frame in the projection target P are contributed by the image light beams ML reflected by different first light splitting elements, and image overlapping or image contact occurs in some blocks, so that in The image frame in the projection target P can still be kept uniform and has good display quality.

FIG. 12A is a schematic diagram of an image frame generated by superimposing the image beams in FIG. 9 and FIG. 11 at the projected target. Referring to FIG. 9, FIG. 11 and FIG. 12A, it can be known that the image frame formed in the projection target P is the image light beam ML reflected from each second light splitting element to form an image frame in the horizontal direction (second direction X), and The image frame formed in the projection target P is the image light beam ML reflected from each first light splitting element, forming an image frame in the vertical direction (the first direction Y). The image frames of the two are superimposed to form an image frame that can be viewed by the projection target P.

FIG. 12B is a schematic diagram of different second light splitting elements reflecting the image beam to the projection target. Referring to FIG. 12B , it can be seen that the image beam passes through the second light splitting element and emits in a diffused manner to the outside of the second waveguide element, but the position of the projection target P can receive the image beam projected by the second light splitting element, and the projection target P Receiving partially overlapping image beams or partially adjacent image beams allows the projection target P to obtain a clear and complete image.

FIG. 13 shows a schematic diagram of an image beam entering the second waveguide element from the first light splitting element according to an embodiment of the present invention. In FIG. 13 , the incident angles of the image beam ML reflected by different first light splitting elements from the first waveguide element 110 to the second waveguide element 120 may be different. Therefore, for different first light splitting elements, the diffusion coating can be Make different designs. The principal ray of part of the image light beam is deflected to the last light-splitting element Y4 of the first light-splitting element through the reflection path of the first light-splitting element Y1 of the first light-splitting element. The principal ray of part of the image beam is deflected to the first light-splitting element Y1 of the first light-splitting element through the path reflected by the last light-splitting element Y4 of the first light-splitting element. The beam direction in FIG. 13 is schematically described, and the actual image beam is incident into the second waveguide element 120 . For example, in FIG. 13 , the traveling direction (first direction Y) of the image light beam ML is, for example, at an angle of 45 degrees relative to the first light splitting element as an incident angle, and the angle at which the image light beam ML is incident on the first light splitting element may be larger than, Less than or equal to 45 degrees (reference angle). For example, the angle at which the image light beam ML is incident on the first light splitting elements Y1 and Y2 may be greater than 45 degrees, as shown in FIG. 14A . FIG. 14A is a schematic diagram of the image beam ML incident on the first light splitting element Y1 , and the incident angle thereof is greater than 45 degrees. The angle at which the image light beam ML is incident on the first light splitting element Y2 can be deduced by analogy. Therefore, for the diffusion coating design of the first light splitting elements Y1 and Y2, it can be designed to have a reflectivity in the areas where the incident angles of the first light splitting elements Y1 and Y2 are 47 degrees and 50 degrees at places where the incident angle is greater than 45 degrees. 15% and 30%, so that the image beam ML reflected from the first light splitting elements Y1 and Y2 to the second waveguide element 120 has a larger amount of light, thereby improving the projection efficiency of the image beam ML to the projection target P. For another example, the angle at which the image light beam ML is incident on the first light splitting elements Y3 and Y4 may be smaller than 45 degrees, as shown in FIG. 14B . FIG. 14B shows a schematic diagram of the image light beam ML incident on the first light splitting element Y4, and the incident angle thereof is less than 45 degrees. The angle at which the image beam ML is incident on the first light splitting element Y3 can be deduced by analogy. Therefore, for the diffusion coating design of the first light splitting elements Y3 and Y4, it can be designed to have reflectivity in the areas where the incident angles of the first light splitting elements Y3 and Y4 are 40 degrees and 43 degrees where the incident angle is less than 45 degrees. 40% and 55%, so that the image beam ML reflected from the first light splitting elements Y3 and Y4 to the second waveguide element 120 has a larger amount of light, thereby improving the projection efficiency of the image beam ML to the projection target P.

Therefore, in the embodiment of the present invention, by adjusting the optical characteristics of the diffusion coating on the light splitting element, the image frame on the projection target P can be made uniform and the light quantity of the image beam ML projected to the projection target P is relatively large.

Several embodiments are given below to describe the operation method of the head-mounted display device including the lighting system, the display and the waveguide system.

FIG. 15 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. Please refer to FIG. 15 , the head-mounted display device 300A of this embodiment includes an illumination system 350A, a display 330A, a lens module 340 and a waveguide system. The lens module 340 may include one or more lenses, and the waveguide system includes a first waveguide element 310 and a second waveguide element 320 . In this embodiment, the display 330A includes, for example, a digital light processing (Digital Light Processing ^™ , DLP ^™ for short) projection system for converting the illumination beam IL from the illumination system 350A into an image beam ML. The image beam ML is transmitted to the projection target P through the waveguide system. In this embodiment, the operation of the waveguide system can be sufficiently taught, suggested and implemented from the description of the embodiment shown in FIGS. 1 to 14B.

In this embodiment, the lighting system 350A is used to provide the lighting beam IL to the display 330A. The illumination system 350A includes an illumination light source 351 , a collimating lens group 353 , an aperture stop 355 , a light homogenizing element 357 and a prism module 359A. The illumination light source 351 provides an illumination light beam IL. The illumination light beam IL is transmitted to the display 330A through the collimating lens group 353 , the aperture stop 355 , the light homogenizing element 357 and the prism module 359A. In this embodiment, the aperture diaphragm 355 is arranged between the collimating lens group 353 and the light uniform element 357, and the illumination light source 351 is, for example, a light emitting diode (light emitting diode, LED), but not limited thereto. The element 357 is, for example, a lens array (fly-eyelens array), and the collimating lens group 353 includes one or more lenses. In this embodiment, the illumination light beam IL from the illumination light source 351 converges to a third stop PA3 within the illumination system 350A. The third diaphragm PA3 is located at the aperture diaphragm 355 . In this embodiment, the aperture diaphragm 355 may have a driving element 358 (such as a motor), and the driving element is used to control the opening size of the aperture diaphragm 355 so as to control the area size of the third diaphragm PA3. Therefore, the aperture stop 355 can adjust the light quantity of the illumination light beam IL passing through its opening. In the present embodiment, the prism module 359A includes a prism 352 (first prism). The illumination light beam IL from the homogenizing element 357 is transmitted to the display 330A through the prism 352 . In another embodiment, according to design requirements, the opening of the aperture stop 355 may have a fixed aperture size.

FIG. 16 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. 15 and 16, the head-mounted display device 300B of this embodiment is similar to the head-mounted display device 300A of FIG.

Specifically, in this embodiment, the display 330A includes, for example, a Liquid Crystal On Silicon (LCoS) projection system for converting the illumination beam IL from the illumination system 350B into an image beam ML. The image beam ML is transmitted to the projection target P through the waveguide system. In this embodiment, the operation of the waveguide system can be sufficiently taught, suggested and implemented from the description of the embodiments shown in FIGS. 1 to 14B. In this embodiment, the lighting system 350B is used to provide the lighting beam IL to the display 330B. The aperture stop 355 is disposed between the collimating lens group 353 and the light homogenizing element 357 . In this embodiment, the illumination light beam IL from the illumination light source 351 converges to the third diaphragm PA3 within the illumination system 350A. The illumination light beam IL of the illumination light source 351 can be transformed into an illumination light beam IL with a single polarity through polarity conversion. The third diaphragm PA3 is located at the aperture diaphragm 355 . In this embodiment, the aperture stop 355 has a driving element. The driving element is used to control the opening size of the aperture diaphragm 355 to control the area size of the third diaphragm PA3. Therefore, the aperture stop 355 can adjust the light quantity of the illumination light beam IL passing through its opening. In this embodiment, the prism module 359B includes a polarizing beam splitter (Polarizing beam splitter, PBS). The illumination light beam IL from the homogenizing element 357 is delivered to the display 330A through the polarization beam splitter, and reflected to the lens module 340 .

FIG. 17 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. Please refer to FIG. 15 and FIG. 17 , the head-mounted display device 300C of this embodiment is similar to the head-mounted display device 300A of FIG. 15 , but the main difference between the two lies in the design of the prism module 359C.

Specifically, in this embodiment, the display 330C includes, for example, a digital light processing (Digital Light Processing ^TM , DLP ^TM ) projection system for converting the illumination beam IL from the illumination system 350C into an image beam ML. The image beam ML is transmitted to the projection target P through the waveguide system. In this embodiment, the operation of the waveguide system can be sufficiently taught, suggested and implemented from the description of the embodiments shown in FIGS. 1 to 14B. In this embodiment, the prism module 359C includes a first prism 359_1 , a second prism 359_2 and a third prism 359_3 . The first prism 359_1 has a curved surface. The curved surface has a reflective layer R. The curved surface is used to reflect the illumination beam IL from the homogenizing element 357 . In this embodiment, there is a slight air gap between the two prisms. For example, the first gap is located between the first prism 359_1 and the second prism 359_2 , and the second gap is located between the second prism 359_2 and the third prism 359_3 . The illumination light beam IL from the homogenizing element 357 is delivered to the display 330C through the first prism 359_1 , the first gap, the curved surface, the second prism 359_2 , the second gap and the third prism 359_3 . In one embodiment, the first prism 359_1 can be adhered to the second prism 359_2, or bonded through a transparent adhesive. The second prism 359_2 can be attached to the third prism 359_3, or bonded through a transparent adhesive.

In the embodiments shown in FIGS. 15 to 17 , the lighting systems 350A, 350B, and 350C have a first F value, and the first F value is determined according to the size of the third diaphragm PA3 . The lens module 340 has a second F-number. The head-mounted display devices 300A, 300B, and 300C meet the condition that the first F-value is greater than or equal to the second F-value, which can eliminate the ghost image generated by reducing the image frame. The F value can be defined as 1/2*sin(θ), and the θ angle is the cone angle of the incident light beam (cone angle).

For example, FIG. 18 shows a schematic diagram of some components of the head-mounted display device in the embodiment of FIG. 17 . For brief description, FIG. 18 only shows the display 330C, the third prism 359_3 and the lens module 340 of the head-mounted display device 300C. In this embodiment, the illumination light beam IL is incident on the display 330C, and the display 330C includes, for example, a digital micromirror device (Digital Micromirror Device, DMD for short). The digital micro-mirror element converts the illumination light beam IL into the image light beam ML, and then reflects the image light beam ML to the third prism 359_3. The third prism 359_3 then reflects the image beam ML to the lens module 340 . In this embodiment, the cone angle of the illumination light beam IL incident on the display 330C is, for example, θ1, and the first F value of the illumination system 350C can be defined as 1/2*sin(θ1). In this embodiment, the lens module 340 receives the image light beam ML from the display 330C, and its cone angle is, for example, θ2. The second F value of the lens module 340 can be defined as 1/2*sin(θ2).

In this embodiment, according to the manufacturer's design, the second F value of the lens module 340 is preset, and the required incident angle θ2 can be obtained. Therefore, the size of the opening passing through the aperture stop 355 can be adjusted. to control the size of the third light bar PA3, and the size of the third light bar PA3 will affect the size of the cone angle θ1 of the illumination light beam IL incident on the display 330C. That is, after the second F value of the lens module 340 is determined, the size of the first F value of the lighting system 350C can be controlled through the aperture stop 355, so that the head-mounted display device 300C meets the first F value greater than or Equal to the second F value condition. In one embodiment, the opening of the aperture stop 355 can be a fixed aperture size, and in conjunction with the design of the second F value of the lens module 340, the size of the first F value of the control lighting system 350C is designed so that the head-mounted display device 300C Meet the condition that the first F value is greater than or equal to the second F value. In the embodiments shown in FIG. 15 and FIG. 16 , the lighting systems 350A, 350B can also be adjusted in this way, so that the head-mounted display devices 300A, 300B meet the condition that the first F value is greater than or equal to the second F value. Therefore, It is easy for the user to eliminate or reduce the presence of ghosts in the viewed image frames or the blurring of the viewed image frames during the use of the head-mounted displays 300A and 300B.

FIG. 19 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. Please refer to FIG. 15 and FIG. 19, the head-mounted display device 400A of this embodiment is similar to the head-mounted display device 300A of FIG. Element 457 is a light integrating rod.

Specifically, in this embodiment, the prism module 459A includes a prism and two lenses, wherein the aperture stop 455 is disposed between the two lenses, and the light homogenizing element 457 is, for example, a light integrating cylinder. In this embodiment, the illumination light beam IL from the illumination light source 451 converges to the third diaphragm PA3 within the illumination system 450A. The third diaphragm PA3 is located at the aperture diaphragm 455 . In this embodiment, the aperture stop 455 has a driving element. The driving element is used to control the opening size of the aperture diaphragm 455 to control the size of the third diaphragm PA3, thereby controlling the size of the cone angle of the illumination light beam IL incident on the display 430A. Therefore, after the second F value of the lens module 440 is determined, the size of the first F value of the lighting system 450A can be controlled through the aperture stop 455, so that the head-mounted display device 400A meets the requirement that the first F value is larger than or Equal to the second F value condition.

FIG. 20 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. Please refer to FIG. 16 and FIG. 20, the head-mounted display device 400B of this embodiment is similar to the head-mounted display device 300B of FIG. Element 457 is a light integrating rod.

Specifically, in this embodiment, the prism module 459B includes two prisms and two lenses, wherein the aperture stop 455 is disposed between the two lenses in the prism module 459B, and the light homogenizing element 457 is, for example, a light integrating cylinder. In this embodiment, the illumination light beam IL from the illumination light source 451 converges to the third diaphragm PA3 within the illumination system 450A. The third diaphragm PA3 is located at the aperture diaphragm 455 . In this embodiment, the aperture stop 455 has a driving element. The driving element is used to control the opening size of the aperture diaphragm 455 to control the size of the third diaphragm PA3, thereby controlling the size of the cone angle of the illumination light beam IL incident on the display 430A. Therefore, after the second F value of the lens module 440 is determined, the size of the first F value of the lighting system 450A can be controlled through the aperture stop 455, so that the head-mounted display device 400A meets the requirement that the first F value is larger than or Equal to the second F value condition.

FIG. 21 is a schematic diagram of a head-mounted display device according to an embodiment of the present invention. Please refer to FIG. 21 , the head-mounted display device 400C of this embodiment includes an illumination system 450C, a display 430C, a lens module 440 and a waveguide system. The waveguide system includes a first waveguide element 410 and a second waveguide element 420 . In this embodiment, the display 330A includes, for example, a digital light processing (Digital Light Processing ^TM , DLP ^TM for short) projection system or a Liquid Crystal On Silicon (LCoS for short) projection system, which is used to transmit the illumination beam from the illumination system 450C to IL is converted into image beam ML. The image beam ML is transmitted to the projection target P through the waveguide system. In this embodiment, the operation of the waveguide system can be sufficiently taught, suggested and implemented from the description of the embodiments shown in FIGS. 1 to 14B.

In this embodiment, the lighting system 450C is used to provide the lighting beam IL to the display 430C. The illumination system 450C includes an illumination light source 451 , a uniform light element 457 , a collimating lens group 453C, an aperture stop 455 and a prism module 459C. The illumination light source 451 provides an illumination light beam IL. The illumination light beam IL is transmitted to the display 430C through the light homogenizing element 357 , the aperture stop 355 , the collimating lens group 453C and the prism module 459C. In this embodiment, the collimating lens group 453C includes lenses 453_1 and 453_2. The aperture stop 455 is arranged between the lenses 453_1 and 453_2 in the collimator lens group 353C. The light homogenizing element 457 is, for example, a light integrating rod. In this embodiment, the illumination light beam IL from the illumination light source 451 converges to the third diaphragm PA3 within the illumination system 450C. The third diaphragm PA3 is located at the aperture diaphragm 455 . In this embodiment, the aperture stop 455 has a driving element. The driving element is used to control the opening size of the aperture diaphragm 455 to control the size of the third diaphragm PA3. Therefore, the aperture stop 455 can adjust the light quantity of the illumination light beam IL passing through its opening. In this embodiment, the prism module 459C includes a first prism 352_1 and a second prism 352_2 . The illumination beam IL from the collimating lens group 453C is reflected to the display 430C through the first prism 352_1 , and the illumination beam IL is transformed into an image beam ML and transmitted to the lens module 440 through the second prism 352_2 .

In this embodiment, the aperture diaphragm 455 can adjust the size of the opening to control the size of the third diaphragm PA3, and the size of the third diaphragm PA3 will affect the size of the cone angle θ1 of the illumination light beam IL incident on the display 430C . Therefore, after the second F value of the lens module 440 is determined, the size of the first F value of the lighting system 450C can be controlled through the aperture stop 455, so that the head-mounted display device 400C meets the requirement that the first F value is larger than or Equal to the second F value condition.

To sum up, in the exemplary embodiment of the present invention, the first light barrier is located inside the first waveguide element, and the second light barrier is located at the projection target, so that the head-mounted display device can provide a large viewing angle, and the waveguide system The size is small. In an exemplary embodiment of the present invention, the diffusion coating of each light splitting element can be determined according to different reflectivity requirements or product design, so that the image frame in the projection target can be kept uniform and has good display quality. In an exemplary embodiment of the invention, a third light bar is located within the illumination system, and the aperture light bar is disposed at the third light bar. The head-mounted display device can control the size of the first F value of the third light barrier and the lighting system through the aperture diaphragm, so that the head-mounted display device meets the requirement that the first F value is greater than or equal to the second F value of the lens module Conditions, thereby improving the ghost image in the video screen and providing good display quality.

The above is only an embodiment of the present invention, and cannot limit the scope of the present invention. That is, all simple equivalent changes and modifications made according to the claims of the present invention and the contents of the description are still patents of the present invention. within the coverage. In addition, any embodiment or claim of the present invention does not necessarily achieve all the objects or advantages or features disclosed in the present invention. In addition, the abstract of the description and the title of the invention are only used to assist in the search of patent documents, and are not used to limit the scope of rights of the present invention. In addition, terms such as "first" and "second" mentioned in the specification or claims are only used to name elements or to distinguish different embodiments or ranges, and are not used to limit the number of elements. upper or lower limit.

List of reference signs

100, 200, 300A, 300B, 300C, 400A, 400B, 400C, 500, 600, 700, 800, 900: Head Mounted Displays

110, 210, 310, 410, 510, 610, 710, 810, 910: the first waveguide element

120, 220, 320, 420, 520, 620, 720, 820, 920: second waveguide element

130, 230, 330A, 330B, 330C, 430A, 430B, 430C, 830: display

140, 240, 340, 440, 840: lens module

350A, 350B, 350C, 450A, 450B, 450C: lighting system

351, 451: lighting source

352, 352_1, 352_2, 359_1, 359_2, 359_3: Prisms

353, 453C: collimating lens group

355, 455: aperture diaphragm

357, 457: Homogenizing components

358: drive element

359A, 359B, 359C, 459A, 459B, 459C: Prism Module

453_1, 453_2: lens

521, 621, 721: reflective structures

530, 630, 730, 850, 930: the third waveguide element

532: Fixing parts

960, 970: polarizing element

A1: optical axis

A2: boresight

A3: Reference axis

D1, D2: distance

ES3: the third light-emitting surface

IS3: The third light incident surface

IL: Lighting Beam

ML: image beam

P: Projection target

PA1: first light bar

PA1’, PA1”, PA1”’: light bar

PA2: second light bar

PA3: third light bar

PC: Center position

R: reflective layer

S11, S13, S14: the first light incident surface

S12, ES1: the first light emitting surface

S23, S15: reflective surface

S21, IS2: the second light incident surface

S22, ES2: Second light emitting surface

SX11, SY21: first surface

SX12, SY22: second surface

SRN, SR(N+1): curve

X: Second direction

X1, X2, X3, X4, X5, X6, 531, 631, 731, 831, 931: the second light splitting element

Y: first direction

Y1, Y2, Y3, Y4, 811, 911: the first light splitting element

Z: third direction

θ1, θ2: cone angle

Claims (14)

1. A head-mounted display device, characterized in that, comprising: a display for providing an image light beam projected to a projection target; The first waveguide element includes a first light incident surface, a first light exit surface and a plurality of first light splitting elements, wherein the image beam from the display enters the first waveguide element through the first light incident surface , the image beam converges to a first aperture within the first waveguide element, and the image beam leaves the first waveguide element through the first light exit surface, wherein the first aperture is located at the within the first waveguide element; and The second waveguide element is connected to the first waveguide element, and the second waveguide element includes a second light incident surface, a second light exit surface, and a plurality of second light splitting elements, wherein all light from the first waveguide element The image beam enters the second waveguide element through the second light incident surface, and the image beam leaves the second waveguide element through the second light exit surface, and the image beam enters the second waveguide element outside is projected to a second light barrier, wherein the second light barrier is located at the projection target. 2. The head-mounted display device according to claim 1, wherein the first light-splitting elements are arranged along a first direction, and the first light bar and the first light-splitting element of the first light-splitting elements The distance between the central position of the center position in the first direction is D1, and the distance between the reference axis and the central position of the first sheet of light splitting element in the first direction is D2, wherein the distance D1 is greater than or equal to the said distance D2, and said projection target has a boresight perpendicular to said first direction, said boresight being translated towards said first waveguide element to produce said reference on a reference plane within said first waveguide element axis, and the reference plane passes through the center of the first light splitting element. 3. The head-mounted display device according to claim 2, wherein the second light splitting elements are arranged along a second direction, and the image light beam is along the first direction within the first waveguide element After passing, the image beam leaves the first waveguide element after being reflected by the first light splitting elements. 4. The head-mounted display device according to claim 3, further comprising: a lens module, having an optical axis, and the lens module is disposed between the display and the first waveguide element, wherein the lens module is used to generate an angle of view corresponding to the image beam received by the projection target perspective. 5. The head-mounted display device according to claim 4, wherein the optical axis of the lens module is perpendicular to the first direction and parallel to the visual axis of the projection target, and the projection target The viewing angle in the diagonal direction of receiving the image formed by the image light beam is 30-50 degrees. 6. The head-mounted display device according to claim 4, wherein the optical axis of the lens module is parallel to the first direction and perpendicular to the visual axis of the projection target, and the projection target The viewing angle of the diagonal direction receiving the image formed by the image light beam is 50-90 degrees. 7 . The head-mounted display device according to claim 4 , wherein the projection target receives the image formed by the image beam at a diagonal angle of 30° to 90°. 8 . 8. The head-mounted display device according to claim 4, wherein the viewing angle generated by the lens module includes a first viewing angle and a second viewing angle, and the size of the first viewing angle is based on the first viewing angle. The waveguide element is determined, and the size of the second viewing angle is determined according to the second waveguide element. 9. The head-mounted display device according to claim 1, wherein the first light incident surface is opposite to the first light exit surface, and the optical axis of the lens module is perpendicular to the first direction. 10. The head-mounted display device according to claim 1, wherein the first light incident surface is adjacent to the first light exit surface, and the optical axis of the lens module is parallel to the first light emitting surface. one direction. 11. The head-mounted display device according to claim 1, wherein the first light incident surface is adjacent to the first light exit surface, and the optical axis of the lens module is perpendicular to the first light emitting surface. a direction and parallel to the second direction. 12. The head-mounted display device according to claim 1, wherein the second light incident surface and the second light exit surface are the same surface. 13. The head-mounted display device according to claim 1, wherein there is an interval between the first waveguide element and the second waveguide element. 14. The head-mounted display device according to claim 1, wherein the number of the plurality of second light-splitting elements of the second waveguide element is greater than the number of the plurality of first light-splitting elements of the first waveguide element. The number of light-splitting elements in one piece.