TWI770415B - Light guide module and augmented reality apparatus having the same - Google Patents

Abstract

A light guide module and an augmented reality (AR) apparatus are disclosed. The AR apparatus includes a display module and the light guide module. The light guide module includes a first light guide plate and a second light guide plate. The first light guide plate has a light receiving area for receiving optical input light with a predetermined incident angle and a light outputting area for outputting optical input light. The second light guide plate is disposed on the first light guide plate, and has dichroic surfaces for selectively transmitting or reflecting the optical input light.

Description

Light guide module and augmented reality with the same environment device

The present invention relates to the field of optics, and particularly relates to a light guide module and an augmented reality device having the light guide module.

Augmented reality (AR) is a technology that places virtual objects in real scenes. With augmented reality technology, users can interact with real and virtual content. Today's augmented reality devices, such as head-mounted displays (HMDs) and head-up displays (HUDs), are used in a variety of applications, including gaming, education, navigation... .and many more. On the other hand, smart glasses are a type of head-mounted displays, which need to guide light beams to the display area through a light guide module, so that users can see virtual images.

The purpose of the present invention is to provide a light guide module and an augmented reality device having the light guide module, wherein the light guide module has a The optical input beam is made to pass through or reflect the dichroic surface of the optical input beam, so as to achieve the effect of optical see-through.

One aspect of the present invention relates to a light guide module comprising a first light guide plate and a second light guide plate. The first light guide plate has a light entrance area and a light exit area, wherein the light entrance area is used for receiving the optical input beam with a predetermined incident angle, and the light exit area is used for outputting the optical input beam. The second light guide plate is arranged on the first light guide plate, and has a plurality of dichroic surfaces for selectively passing or reflecting the optical input light beam.

According to one or more embodiments of the present invention, the predetermined incident angle is substantially 70 degrees.

According to one or more embodiments of the present invention, the refractive indices of the first light guide plate and the second light guide plate are substantially the same.

According to one or more embodiments of the present invention, the optical input beam generates total internal reflection on a surface of the second light guide plate far from the first light guide plate.

According to one or more embodiments of the present invention, the light guide module further includes a third light guide plate, which is disposed on the second light guide plate, and which and the first light guide plate are respectively located opposite to the second light guide plate. sides.

According to one or more embodiments of the present invention, the above-mentioned optical input beam generates total internal reflection on the surface of the above-mentioned third light guide plate far from the above-mentioned second light guide plate.

According to one or more embodiments of the present invention, the dichroic surfaces reflect the light traveling from the third light guide plate and pass the light from the first light guide plate.

According to one or more embodiments of the present invention, the thicknesses of the first light guide plate and the third light guide plate are substantially the same.

According to one or more embodiments of the present invention, the total thickness of the first light guide plate, the second light guide plate and the third light guide plate is substantially 2 mm to 3 mm.

According to one or more embodiments of the present invention, the above-mentioned dichroic surfaces are substantially arranged parallel to each other.

According to one or more embodiments of the present invention, the inclination angle of each of the above-mentioned dichroic surfaces is substantially half of the above-mentioned predetermined incident angle.

According to one or more embodiments of the present invention, the above-mentioned dichroic surfaces are arranged at a predetermined interval, and the predetermined interval is greater than or equal to t×tan(θ′), where t is the thickness of the second light guide plate, and θ′ is the inclination angle of the above-mentioned dichroic planes.

According to one or more embodiments of the present invention, the above-mentioned light guide module further includes an input lamp, which is located on the light incident area of the above-mentioned first light guide plate.

Another aspect of the present invention relates to an augmented reality (AR) device, which includes a display module and a light guide module. The display module is configured to provide an optical input beam. The light guide module includes a first light guide plate and a second light guide plate. The first light guide plate has a light entrance area and a light exit area, wherein the light entrance area is used for receiving the optical input beam with a predetermined incident angle, and the light exit area is used for outputting the optical input beam. The second light guide plate is arranged on the first light guide plate, and has a plurality of dichroic surfaces for selectively passing or reflecting the optical input light beam.

According to one or more embodiments of the present invention, the light guide module further includes a third light guide plate, which is disposed on the second light guide plate, and which and the first light guide plate are respectively located opposite to the second light guide plate. sides.

According to one or more embodiments of the present invention, the total thickness of the first light guide plate, the second light guide plate and the third light guide plate is substantially 2 mm to 3 mm.

According to one or more embodiments of the present invention, the above-mentioned augmented reality device further includes a collimating member, which is interposed between the above-mentioned display module and the above-mentioned light guide module.

According to one or more embodiments of the present invention, the display module is a liquid-crystal-on-silicon (LCoS) display module or a digital light processing (DLP) module.

According to one or more embodiments of the present invention, the above-mentioned augmented reality device further includes a body, which is coupled to the above-mentioned display module and the above-mentioned light guide module.

According to one or more embodiments of the present invention, the above-mentioned body is a spectacle frame.

10‧‧‧Augmented reality device

12‧‧‧Display Module

14, 100, 100 ' ‧‧‧Light guide module

14A‧‧‧Augmented Reality Display Area

16‧‧‧Main body

16A‧‧‧Frame front

16B‧‧‧ Temple

18‧‧‧Driver circuit board

20‧‧‧Alignment member

110‧‧‧First light guide plate

110A‧‧‧Light entrance area

110B‧‧‧Light output area

112‧‧‧Input

120‧‧‧Second light guide plate

122‧‧‧Color separation surface

130‧‧‧Third light guide plate

‧‧‧視角

‧‧‧Perspective

D‧‧‧Display

L1‧‧‧Optical Input Beam

L2‧‧‧beam

For a more complete understanding of the embodiments and their advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein: [FIG. 1] is a schematic diagram of a light guide module according to one or more embodiments of the present invention; [Fig. 2] exemplarily shows the transmission of the optical input beam inside and outside the light guide module of [Fig. 1]; [Fig. 3] is a detailed view of the illustration of [Fig. 2]; [Fig. 4] Example Fig. 1 schematically shows the light guide module through which the front beam penetrates [Fig. 1]; [Fig. 5] is a schematic diagram of the light guide module according to one or more embodiments of the present invention; [Fig. 6] is a schematic diagram of one or more embodiments of the present invention. An example of an augmented reality device of various embodiments; and [FIG. 7] is a functional block diagram of some elements of the augmented reality device shown in [FIG. 6].

The following will clearly illustrate the spirit of the present disclosure with drawings and detailed descriptions. Anyone with ordinary knowledge in the technical field, after understanding the preferred embodiments of the present disclosure, may be able to make changes and modifications by the techniques taught in the present disclosure. modifications, which do not depart from the spirit and scope of this disclosure.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, parts, regions, layers and/or sections, these terms should not be limiting elements, parts, regions, layers and/or sections. These terms are only used to distinguish one element, component, region, layer and/or section from another element, component, region, layer and/or section.

The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the claims. Unless otherwise limited, the singular form "a" or "the" may also be used to refer to the plural form.

In addition, the use of spatially relative terms is intended to describe different orientations of elements in use or operation, and is not limited to the orientation shown in the drawings. Elements may also be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein may be interpreted in the same manner.

For simplicity and clarity of illustration, reference numerals and/or letters may be repeated herein among various embodiments, but this does not imply a causal relationship between the various embodiments and/or configurations discussed.

1 is a schematic cross-sectional view of a light guide module 100 according to one or more embodiments of the present invention. The light guide module 100 includes a first light guide plate 110 , a second light guide plate 120 and a third light guide plate 130 which are stacked on each other. The first light guide plate 110 has a light entrance area 110A and a light exit area 110B, wherein the light entrance area 110A is used for receiving the optical input light beam, and the light exit area 110B is used for outputting. The optical input light beam penetrates the light incident area 110A at a predetermined incident angle and enters the first light guide plate 110 . The optical input beam can be provided by a display D, which can be, for example, a liquid-crystal-on-silicon (LCoS) display module (such as a front-illuminated liquid crystal-on-silicon display module), digital light processing; DLP) modules, micro-LED display modules, or other suitable display modules. In addition, the input lens 112 may be disposed on the light incident region 110A to couple the optical input beam into the first light guide plate. Further, the input aperture 112 may be aligned with the light incident area 110A. The optical input light beam exits the first light guide plate 110 through the light exit region 110B at a field of view (FOV). The refractive index of the first light guide plate 110 is equal to or greater than 1/sin(θ) to achieve total internal reflection, where θ is a predetermined incident angle of the optical input beam.

The second light guide plate 120 is disposed on the first light guide plate 110 and has a plurality of dichroic surfaces 122 for selectively allowing the optical input beam to pass through or reflect the optical input beam. Each dichroic surface 122 may be made of, for example, a half mirror. The dichroic surfaces 122 are arranged substantially parallel to each other, and the inclination angle of each dichroic surface 122 is approximately half of the predetermined incident angle. In addition, the dichroic surfaces of the dichroic surfaces 122 are arranged at a predetermined interval, and the predetermined interval is greater than or equal to t ₁₂₀ ×tan(θ'), where t ₁₂₀ is the thickness of the second light guide plate 120 , and θ' is each color separation Angle of inclination of face 122 .

The third light guide plate 130 is disposed on the second light guide plate 120 and is opposite to the first light guide plate 110 . Similarly, the refractive index of the third light guide plate 130 is equal to or greater than 1/sin(θ) to achieve total internal reflection to prevent the optical input beam from penetrating outside the light guide module 100 , where θ is the predetermined incidence of the optical input beam horn.

The refractive indices of the first light guide plate 110 , the second light guide plate 120 and the third light guide plate 130 may be substantially the same. Furthermore, in some embodiments, the thicknesses of the first light guide plate 110 and the third light guide plate 130 may be substantially the same.

Each of the first light guide plate 110, the second light guide plate 120, the third light guide plate 130 and the input lens 112 may be made of optically transparent materials, such as glass, quartz, epoxy, polycarbonate, polymethyl methacrylate (polymethyl methacrylate; PMMA) or similar. In some embodiments, the materials of the first light guide plate 110 , the second light guide plate 120 , the third light guide plate 130 and the input lens 112 are the same.

FIG. 2 exemplarily illustrates the conduction of the optical input beam inside and outside the light guide module 100 . As shown in FIG. 2 , except for the light incident area 110A and the light exit area 110B, on the outer surface of the light guide module 100 , that is, the surface of the first light guide plate 110 away from the second light guide plate 120 and the surface of the third light guide plate 130 away The surface of the second light guide plate 120 reflects the optical input beam in the way of total internal reflection, so that the optical input beam is conducted from the light entrance area 110A to the light exit area 110B in the light guide module 100 . The width of the light incident area 110A is equal to or less than 2×t ₁₁₀ ×tan(θ) to prevent the optical input beam from returning to the input sphere 112, where t ₁₁₀ is the thickness of the first light guide plate 110, and θ is the thickness of the optical input beam. predetermined angle of incidence.

The optical input beam that penetrates to the second light guide plate 120 or generates total internal reflection on the surface of the third light guide plate 130 away from the second light guide plate 120 substantially penetrates to the second light guide plate 120, and then penetrates to the second light guide plate 120. Three light guide plates 130 . Some light beams traveling from the first light guide plate 110 can penetrate the dichroic surface 122 and go toward the third light guide plate 130 . Some of the light beams traveling from the third light guide plate 130 may be reflected by the dichroic surface 122 toward the first light guide plate 110 , and then exit the first light guide plate 110 through the light exit region 110B.

The optical input beam penetrating to the third light guide plate 130 generates total internal reflection on the surface of the third light guide plate 130 away from the second light guide plate 120 , and then penetrates to the third light guide plate 130 .

The predetermined incident angle of the optical input beam may be about 70 degrees, and the thickness of the light guide module 100 (ie, the total thickness of the first light guide plate 110, the second light guide plate 120 and the third light guide plate 130) may be about 2 mm to 3mm to meet the trend of miniaturization.

達到大約30度。 FIG. 3 is a detailed view of the depiction of FIG. 2 . In some examples, the refractive index of each of the first light guide plate 110 , the second light guide plate 120 and the third light guide plate 130 is about 1.517, and the first light guide plate 110 , the second light guide plate 120 and the third light guide plate 130 have a refractive index of about 1.517. The thicknesses of 130 are about 0.5 mm, 1.1 mm, and 0.5 mm, respectively, the predetermined incident angle is about 70 degrees, the inclination angle of each dichroic surface 122 is about 35 degrees, and the optical input beam comes from the collimating member, which has about 14.1mm effective focal length. The optical input light beam L1 is coupled within the light guide module 100 and then output through the first light guide plate 110 . With the above configuration, the viewing angle

to about 30 degrees.

FIG. 4 exemplarily shows that the front light beam penetrates the light guide module 100 . As shown in FIG. 4 , the light beam L2 on the front side of the light guide module 100 can penetrate the third light guide plate 130 , the second light guide plate 120 and the first light guide plate 110 in sequence to the back side of the light guide module 100 .

FIG. 5 is a schematic diagram of a light guide module 100 ′ according to one or more embodiments of the present invention. Compared with the light guide module 100 shown in FIG. 1 , the light guide module 100 ′ includes a first light guide plate 110 , a second light guide plate 120 and an input lens 112 but does not include a third light guide plate 130 . In this example, except the light incident area 110A and the light exit area 110B, the surface of the first light guide plate 110 away from the second light guide plate 120 and the surface of the second light guide plate 120 away from the first light guide plate 110 are totally reflected internally. The optical input light beam is reflected in the light guide module 100 ′ , so that the optical input light beam is guided from the light entrance area 110A to the light exit area 110B in the light guide module 100 ′. Other configurations of the first light guide plate 110 , the second light guide plate 120 and the input lens 112 of the light guide module 100 ′ may be similar to those of the light guide module 100 , so the description is not repeated here.

FIG. 6 is an example of an augmented reality device 10 in accordance with one or more embodiments of the present invention. The augmented reality device 10 includes a display module 12 , a light guide module 14 and a body 16 . Display module 12 is configured to provide an optical input beam (ie, emit an image beam) toward light guide module 14, and light guide module 14 couples the optical input beam into it and then in its augmented reality display area 14A. The optical input beam is coupled out. The display module 12 can be, for example, a liquid crystal display module on silicon, a digital light processing module, a micro-LED display module, or other suitable display modules. The light guide module 14 can be implemented by the light guide module 100 of FIG. 1 , the light guide module 100 ′ of FIG. 4 , or the like. For example, if the light guide module 14 is implemented with the light guide module 100 of FIG. 1 , the display module 12 emits an image beam to penetrate the light incident area 110A of the first light guide plate 110 into the light guide module 14 . The body 16 is coupled to the display module 12 and the light guide module 14 . In some embodiments, as shown in FIG. 6 , the body 16 is an eyeglass frame. In this example, the body 16 has a frame front 16A and a temple 16B, wherein the frame front 16A engages with the light guide module 14 , and the temple 16B engages the display module 12 , and the augmented reality device 10 may be referred to as an optical A see-through head-mounted display (HMD). That is to say, when the augmented reality device 10 is worn on the user's head, the user can see the real image in front of the light guide module 14 as well as the real image generated by the display module 12 and in the light guide module 14 Conducted virtual images of both. It should be noted that the augmented reality device 10 shown in FIG. 6 corresponds to the left eye of the user, and those skilled in the art can directly understand that the augmented reality device 10 can be changed to correspond to the right eye of the user. eye or both eyes.

The augmented reality device 10 can be used not only in head-mounted displays, but also in various other applications. In some embodiments, the augmented reality device 10 is applied to a smart phone or a car, wherein the body 16 may be, for example, a case of a smart phone or a car frame, but not limited thereto.

In some embodiments, the augmented reality device 10 further includes a power supply module (not shown) for providing power to the display module 12 and/or other electronic components in the augmented reality device 10 . For aesthetic requirements, the power supply module can be embedded in the main body 16 . In addition, the power supply module may be a rechargeable battery, a disposable battery or other components suitable for providing power.

In some embodiments, the augmented reality device 10 further includes a microprocessor (not shown), which is used to control the display module 12 to display an image (ie, emit an image beam) according to its operation. The augmented reality device 10 generally includes an input interface (eg, physical buttons or a touch panel), a communication interface (eg, a wireless transceiver), and/or other interfaces suitable for receiving data and/or operating instructions.

FIG. 7 is a functional block diagram of some elements in the augmented reality device 10 shown in FIG. 6 . The display module 12, the driving circuit board 18 and the alignment member 20 can be assembled into a single module. In some embodiments, the display module 12 is mounted on the driving circuit board 18, and the driving circuit board 18 has a driver (not shown) for driving the display module 12 to display an image (ie, emit an image beam). The collimating member 20 is interposed between the display module 12 and the light guide module 14, and can be composed of one or more reflective elements and/or refractive elements, such as a convex lens, a Fresnel lens or the like.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the appended patent application.

100‧‧‧Light guide module

110‧‧‧First light guide plate

110A‧‧‧Light entrance area

110B‧‧‧Light output area

112‧‧‧Input

120‧‧‧Second light guide plate

122‧‧‧Color separation surface

130‧‧‧Third light guide plate

D‧‧‧Display

Claims (11)

A light guide module, comprising: a first light guide plate with a light entrance area and a light exit area, the light entrance area is used to receive an optical input beam with a predetermined incident angle, and the light exit area is used to output the optical beam input light beam, and the predetermined incident angle is substantially 70 degrees; and a second light guide plate, disposed on the first light guide plate, the second light guide plate has a plurality of dichroic surfaces, one of each of the dichroic surfaces the inclination angle is substantially half of the predetermined incident angle; and a third light guide plate disposed on the second light guide plate, the third light guide plate and the first light guide plate are respectively located on opposite sides of the second light guide plate; The refractive index of the first light guide plate, the second light guide plate and the third light guide plate are all about 1.517, the thickness of the second light guide plate is about 1.1 mm, the first light guide plate, the second light guide plate and the The total thickness of the third light guide plate is substantially 2 mm to 3 mm, and the dichroic surfaces are used to allow the light beam traveling from the first light guide plate to the third light guide plate in the optical input light beam to pass through and to reflect Among the optical input light beams, the light beam traveling from the third light guide plate toward the first light guide plate causes the optical input light beam to pass through the light exit area and leave the first light guide plate. The light guide module according to claim 1, wherein the dichroic surfaces are arranged at a predetermined interval, and the predetermined interval is greater than or equal to t×tan(θ'), wherein t is the distance between the second light guide plate thickness, and θ' is the inclination angle of the dichroic planes. The light guide module as claimed in claim 1, wherein the optical input beam generates total internal reflection on a surface of the third light guide plate away from the second light guide plate. The light guide module according to claim 1, wherein the thicknesses of the first light guide plate and the third light guide plate are substantially the same. The light guide module according to claim 1, wherein the dichroic surfaces are substantially arranged parallel to each other. The light guide module as described in item 1 of the scope of the application further comprises: an input lamp located on the light incident area of the first light guide plate. An augmented reality (AR) device, comprising: a display module configured to provide an optical input beam; and a light guide module, comprising: a first light guide plate having a light entrance area and a light exit area, the light entrance area is used for receiving the optical input beam, the light exit area is used for outputting the optical input beam, wherein the optical input beam has a predetermined incident angle, and the predetermined incident angle is substantially 70 degrees; a second light guide plate disposed on the first light guide plate, the second light guide plate has a plurality of dichroic surfaces, an inclination angle of each of the dichroic surfaces is substantially half of the predetermined incident angle; and a first Three light guide plates are arranged on the second light guide plate, the third light guide plate and the first light guide plate are respectively located on opposite sides of the second light guide plate; wherein the first light guide plate, the second light guide plate and the The refractive index of the third light guide plate is all about 1.517, the thickness of the second light guide plate is about 1.1 mm, and the total thickness of the first light guide plate, the second light guide plate and the third light guide plate is substantially 2 mm to 3 mm mm, the dichroic surfaces are used to pass the light beam traveling from the first light guide plate toward the third light guide plate in the optical input beam, and to reflect the optical input beam from the third light guide plate toward the third light guide plate. A light beam traveling from a light guide plate, so that the optical input light beam leaves the first light guide plate through the light exit area. The augmented reality device as described in item 7 of the claimed scope further comprises: a collimating member interposed between the display module and the light guide module. The augmented reality device of claim 7, wherein the display module is a liquid-crystal-on-silicon (LCoS) display module or a digital light processing; DLP) module. The augmented reality device as described in item 7 of the scope of the patent application further comprises: a main body connecting the display module and the light guide module. The augmented reality device as described in claim 10, wherein the system is an eyeglass frame.

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