WO2023095082A1

WO2023095082A1 - Optical arrangement to create extended reality

Info

Publication number: WO2023095082A1
Application number: PCT/IB2022/061465
Authority: WO
Inventors: László Rajmund HAVASI; József PINTÉR
Original assignee: Havasi Laszlo Rajmund; Pinter Jozsef
Priority date: 2021-11-29
Filing date: 2022-11-28
Publication date: 2023-06-01
Also published as: HU5568U

Abstract

The subject of the invention is an optical arrangement to create extended reality, which includes a switch (1), two polarizers (2a, 2b), a beam splitter (3), an image projector (6), and a compute module (7), and the compute module (7) is in electronic connection with the image projector (6). A distinctive feature of the invention is that it includes a ringed polarizer switch (4) and dual focal Fresnel lens (5); the ringed polarizer switch (4) is fitted onto the dual focal Fresnel lens (5); the dual focal Fresnel lens (5) includes at least two rings (5a, 5b) with different focal lengths; and the planes of the two polarizers (2a, 2b) are at least approximately perpendicular to each other.

Description

Optical arrangement to create extended reality

The subject of the patent application is an optical arrangement to create extended reality.

The optical arrangement can form part of Extended Reality (XR) glasses mainly. XR is a broad term that includes Augmented Reality (AR), Mixed Reality (MR, and Virtual Reality (VR) type extended reality. The optical arrangement according to the invention can therefore form the basis of any type of XR glasses.

The state of the art includes the following solutions.

Japanese patent document No JP2019109534A aims to be suitable for high quality VR and/or AR display, in a manner that is convenient for human eyes. To this end, it includes special multi-part lens.

US patent application No US2021149197A1 describes glasses that can be used in both VR and AR mode, and it uses a flat transparent projector. An electronically modulated dynamic lens is located both in front of and behind the transparent projector. The two dynamic lenses act differently under orthogonally polarized lights, so that these dynamic lenses can be used to adjust object distance (sharp distance) where viewed through the glasses. While the dynamic lenses of the invention allow for switching light according to direction of polarization, it does so using an entirely different structure and composition; the dynamic lens does not have a ringed polarizer switch.

The complex lens described in international patent description No W02020013829A1 also includes polarizers, which can be switched on and off, and it aims to be able to project different virtual images at different planes close to the user's eyes in a non-strenuous way. The invention produces different image planes with two liquid crystal lenses with variable focal lengths. Fundamentally, the glasses are a wave conduction arrangement with a hologram input and/or output. This is complemented by liquid crystal lenses with variable focal lengths. The different image planes, which can be switched on and off, are located at different distances from the glasses, so that they can increase the comfort of the person waring the glasses. The fluid crystal lenses are sensitive to polarization and they can be switched electronically. An electronically controlled polarization rotator is located between the lenses. Switching between external and generated lights is not handled by a Fresnel lens and a ringed polarizer switch. US patent application No US9632315B2 describes AR glasses, where the invention includes a Fresnel lens optical system and a mirror input. The glasses do not include a ringed polarizer switch. US patent application No US10859834B2 describes a space-efficient optical system for AR glasses. The arrangement presented does not include dual focal Fresnel lens or a ringed polarizer switch.

In summary, none of the known solutions is capable of operating in safe mode in a situation where the batteries are depleted or power supply is stopped for any other reason. Most known XR glasses allow its user to observe reality using cameras mounted onto the glasses; turning of such cameras is time-consuming, and the cameras cannot work without electricity. Another problem is that the same tool cannot be used to observe VR and the real world due to the difference in focal lengths.

The purpose of the invention is to eliminate the shortfalls of known solutions and to implement an arrangement that can switch from extended reality (AR, MR, or VR) to the real world in a short period of time; that is, to switch to operating as a traditional free-view glasses.

The inventive step is based on the recognition that a solution, which is more advantageous than the previous ones, may be created by implementing the arrangement according to claim 1.

In line with the desired purpose, the most general implementation form of the solution according to the invention may be realized according to claim 1. The various implementation forms are described in the sub-claims.

In line with the desired purpose, the solution according to the invention is an optical arrangement to create extended reality, which includes a switch, two polarizers, a beam splitter, an image projector, and a compute module, and the compute module is in electronic connection with the image projector. A distinctive feature of the invention is that it includes a ringed polarizer switch and dual focal Fresnel lens; the ringed polarizer switch is fitted onto the dual focal Fresnel lens; the dual focal Fresnel lens includes at least two rings with different focal lengths; and the planes of the two polarizers are at least approximately perpendicular to each other.

Another distinctive feature of the invention is that the plane of the beam splitter and the plane of the polarizers form a 40° to 50° angle, suitably an approximately 45° angle. Another distinctive feature is that the plane of the beam splitter and the plane of the ringed polarizer switch and the dual focal Fresnel lens form a 40° to 50° angle, suitably an approximately 45° angle.

In another implementation form, the beam splitter is a wire-grid beam splitter or a semitransparent mirror.

Another distinctive feature can be that the image projector is a mobile phone and/or the image projector includes a polarizer.

Another distinctive feature can be that the switch includes one of the polarizers.

Another distinctive feature can be that the rings of different focal lengths are placed next to each other and taking turns in the dual focal Fresnel lens, and the number of rings placed next to each other and taking turns is arbitrary.

Another distinctive feature can be that the arrangement is built into extended reality (XR) glasses.

The invention is presented in more detail using drawings of the possible implementation forms. On the attached drawings,

Figure 1 shows a theoretical drawing of a possible implementation form of the arrangement, Figure 2 shows a theoretical drawing of another possible implementation form of the arrangement,

Figure 3 shows a side-view of a traditional and known Fresnel lens,

Figure 4/a shows a side-view of a dual focal Fresnel lens that forms part of the invention, Figure 4/b shows an enlarged drawing of a segment of the dual focal Fresnel lens shown on Figure 4/a,

Figure 5 shows the front-view of the ringed polarizer switch.

Figure 1 shows a theoretical drawing of a possible implementation form of the arrangement. In this implementation form, the arrangement advantageously includes at least one light switch 1 (or darkening filter); two polarizers 2 that are perpendicular to each other; at least one beam splitter 3, at least one ringed polarizer switch 4, at least one dual focal Fresnel lens 5, at least one image projector 6, and a compute module 7. The position of the user's eye is also indicated on the drawing.

The switch 1 is capable of blocking light from the outside, and it can be activated with an electric control signal. As a possibility, the switch 1 can be implemented as a large LCD with one pixel. The polarizer 2 makes it possible to filter the outside world and internal light. One polarizer 2a filters lights from the outside world, and the other polarizer 2b filters lights of the virtual content generated by the image projector 6. In the implementation form shown on Figure 1, the planes of the two polarizers 2 are at least approximately perpendicular to each other. Polarizer 2b, which is capable of filtering out lights of the virtual content created by the image projector 6, is typically perpendicular to the plane of the dual focal Fresnel lens 5.

The polarization axes of the two light beams arriving on the beam splitter 3, i.e. the light from the outside world and from the virtual content created by the image projector 6, are at least approximately perpendicular. The role of the beam splitter 3 is that it combines and transmits in one direction the light beams from the two light sources (outside world and virtual content created by the image projector 6). In this implementation form, the beam splitter 3 and the plane of the polarizers 2 form an at least approximately 40° to 50° angle, suitably a 45° angle. In this implementation form, the beam splitter 3 is a semi-transparent mirror 3b. Due to the implementation of the beam splitter 3, dynamic backlight can be displayed, which enhances user experience. This dynamic backlight is sensed by the user’s peripheral vision as if an even larger space segment were visible beyond the projected virtual content. With this solution and when the arrangement is applied in XR glasses, the dark part surrounding the virtual content on the inner surface can be reduced.

The ringed polarizer switch 4 ensures that light arrives at the outside-focused rings of the dual focal Fresnel lens 5 from the outside world only; and that internal light, i.e. virtual content created by the image projector 6, arrives at the projection-focused rings of the dual focal Fresnel lens 5 only. Because of the ringed polarizer switch 4, the user can see sharply both the AR, MR, or VR image and the real world. The ringed polarizer switch 4 can fit to the rings of the dual focal Fresnel lens 5. The ringed polarizer switch 4 is advantageously very tightly fitted to the dual focal Fresnel lens 5, and its ringed layout fits to the rings of the dual focal Fresnel lens 5.

The implementation of the dual focal Fresnel lens 5 is special, because it has a variety of rings, and the rings have different designs for the outside world (reality, marked as a tree on the drawings) and internal lights (virtual content created by the image projector 6, marked as a ghost). This makes it possible to display contents from different sources with appropriate sharpness. The rings 5a, i.e. the odd lens of the dual focal Fresnel lens 5, make it possible to display virtual content from the image projector 6. The rings 5b, i.e. the even (each second) rings, or lens, of the dual focal Fresnel lens 5, are the ones that let reality pass through. The plane of the rings 5b is typically parallel with the plane of the polarizer 2a that filters light from the outside world, but other implementation forms are also possible, e.g. when using dioptric glasses. The ring 5a is designed with a shorter focal length than the ring 5b, which has a more distant focus. In the examples shown on the drawings, the two rings 5a, 5b of different focal lengths are placed next to each other taking turns several times. However, it is important to note that the dual focal Fresnel lens 5 is not limited to operating with alternating rings 5a, 5b only. The number of rings 5a, 5b with different focal lengths is arbitrary in the dual focal Fresnel lens 5. Content selection between the rings 5a, 5b is carried out by the polarizers 2 and the ringed polarizer switch 4. The ringed polarizer switch 4 filters light so that virtual image is projected to rings 5a and/or external light is allowed to the flat rings 5b.

When using in AR or MR mode, beams of the virtual content created by the image projector 6 are projected to the rings 5a, and light rays from the outside world are projected to the rings 5b simultaneously. Thus, extended or mixed reality is created before the eyes of the user. AR and MR mode can be switched to VR mode at any time, or the arrangement can be switched entirely so that only the real world is seen by the user, and the image projector 6 does not project any virtual content. In VR mode, the arrangement does not use any light from the outside world, only from the image projector 6, so that virtual content is projected onto the rings 5a. These modes can be used in succession, in any order and for any period of time. The compute module assists changing and switching between modes.

AR, MR, and VR can be switched off not only by the user but also in emergency situations or when a problem occurs, e.g. the battery dies. In such a situation, the ringed polarizer switch 4 allows light from the outside world to pass through, thus the real image reaches the rings 5b.

The image projector 6 is a unit that produces virtual content and includes lens and optical components. Its role is to direct the beams of virtual content to the beam splitter 3. For example, the image projector 6 can be a mobile phone or a projector. The image projector 6 can even include the polarizer 2b or another polarizer 2. The image projector 6 is designed and placed in the arrangement so that the focal length is properly adjusted. When a mobile phone is used in the arrangement as an image projector 6, the recommended size of the mobile display is 5.5", as it can already create an appropriate resolution. It is also recommended to place the mobile phone above the user’s head, so that the load on the user's neck is limited.

The compute module 7 is connected to the image projector 6. The compute module 7 can be a built-in or external unit; for example, a computer can be used as a compute module 7.

Figure 2 shows a theoretical drawing of another possible implementation form of the optical arrangement. In this implementation form, the arrangement includes similar components than the solution shown in Figure 1 : it includes at least one switch 1; advantageously two polarizers 2 that are perpendicular to each other, so that the polarizer 2b, which filters the lights of the virtual content created by the image projector 6, is integrated into the image projector 6 and/or the polarizer 2a, which filters light from the outside world, is integrated into the switch 1. The optical layout also includes at least one beam splitter 3, at least one ringed polarizer switch 4, at least one dual focal Fresnel lens 5, at least one image projector 6, and at least one compute module 7. The position of the user's eye is also indicated on the drawing.

In the implementation form shown on Figure 2, the switch 1 includes the polarizer 2a. In this implementation form, the beam splitter 3 is a wire-grid polarizer 3a. For example, the image projector 6 can be a mobile phone or a projector that typically includes the polarizer 2b. An advantage of using a wire-grid beam splitter 3a over a semi-transparent mirror 3b is that it does not to modify the polarization axis, meaning that the beam splitter 3 can be adjusted more accurately.

In an advantages situation, there are two polarizers 2 that are perpendicular to each other, but they can also be integrated into other units, such as shown on with Figure 2. In other respects, the components and functioning of the arrangement shown on Figure 2 have the same features as those of the implementation form shown on Figure 1.

Any implementation form of the optical arrangement can include additional components to improve the VR, AR, and/or MR experience; for example, various sensors, such as sensors that monitor the outside world or the head movements of the user. The arrangement can also include, optionally, a communication unit, a battery, a helmet part, a protective plastic shield, or cables to an optional external compute module 7. Other possible additional solutions include optical components that can be adjusted to different head sizes and eye distances, as well as special dual focal Fresnel lens 5 for persons wearing glasses, or modified arrangements for short- and farsighted persons.

The components of the optical arrangements shown on Figures 1 and 2 (e.g. the width and number of rings 5a, 5b, the angle and relative distance of individual components) can be scaled, designed and modelled for specific devices and needs. It is important to note that the arrangements shown on Figures 1 and 2, as well as any of such arrangements modified for, for example, short- or farsighted persons, can be integrated into diving goggles, XR (AR, MR and/or VR) glasses or helmets.

Figure 3 show the already known Fresnel lens, meaning that it is not a part of the invention. The already known Fresnel lens has angled ring parts only.

Figures 4/a and 4/b show a special dual focal Fresnel lens 5. Figure 4/b shows an enlarged image of a segment, so that the differences in comparison to a traditional Fresnel lens can be inspected.

In the implementation forms shown on Figures 4/a and 4/b, the dual focal Fresnel lens 5 includes alternating rings 5a and rings 5b of a different focal length, the latter being flat in this implementation form. A dual focal Fresnel lens 5 can even include 10 to 100 alternating rings 5a and rings 5b. Of course, alternating placement is not the only possible placement method. The rings 5a of the dual focal Fresnel lens 5 make it possible to view the virtual content created by the image projector 6, meaning that their focal length is shorter. The other rings, i.e. lens parts, of the dual focal Fresnel lens 5 are flat rings 5b, which have a larger focal length and offer a view of the outside world. Content selection between the rings 5a, 5b is carried out by the polarizers 2 and the ringed polarizer switch 4. The ringed polarizer switch 4 allows virtual content created by the image projector 6 to reach the rings 5a, and/or external light to reach the rings 5b. When light is allowed to reach both rings 5a, 5b, a mixed reality (MR) or augmented reality (AR) mode can be used.

The arrangement described above has numerous advantages. The most significant advantage of the invention is that it can switch from extended reality to the real world in a short period of time, meaning that it can serve as basis for an extremely safe XR glasses. Another advantage is that it is capable of creating AR, MR, and VR, and switching to the real world is possible from any operating mode. Another advantage is that it can be implemented at low cost, as it can be built from very affordable components. The price of the arrangement is negligible in comparison to OLED displays, micro projectors, and wave driving devices. The price is especially low where the arrangement includes a mobile phone. Another advantage is its wide viewing angle, which approaches the viewing angle of the market leading VR glasses and is multiple times the angle of AR (e.g. HoloLens) glasses. Where a mobile phone is included, an advantage is that it does not burden the neck, and it contains most of the required electronics modules.

An advantage is that the arrangement can be even part of XR diving goggles or diving helmets. This would allow users to enjoy a quite substantial underwater experience, and they can enjoy an exciting virtual, extended or mixed reality experience on the slides of baths. An advantage is that the user can immediately switch to the real world even when using such applications, so that the user is perfect safety even, e.g. when jumping into a pool, or sliding, or when the battery of the XR device dies. If implemented in a diving helmet, the optical arrangement presented in this description can give users a special extended reality experience throughout the day.

The typical field of use of the invention is XR glasses, which XR glasses can be even diving goggles or a helmet, e.g. XR glasses integrated into a tactical helmet.

In addition to the above examples, the invention can be implemented in other forms within the scope of protection.

Claims

9 CLAIMS

1. An optical arrangement to create extended reality, which includes a switch (1), two polarizers (2a, 2b), a beam splitter (3), an image projector (6), and a compute module (7), and the compute module (7) is in electronic connection with the image projector (6), characterized in that it includes a ringed polarizer switch (4) and dual focal Fresnel lens (5); the ringed polarizer switch

(4) is fitted onto the dual focal Fresnel lens (5); the dual focal Fresnel lens (5) includes at least two rings (5a, 5b) with different focal lengths; and the planes of the two polarizers (2a, 2b) are at least approximately perpendicular to each other.

2. The arrangement according to claim 1, characterized in that the plane of the beam splitter (3) and the plane of the polarizers (2a, 2b) form a 40° to 50° angle, suitably an approximately 45° angle.

3. Any of the arrangements according to claim 1 or 2, characterized in that the plane of the beam splitter (3) and the plane of the ringed polarizer switch (4) and the dual focal Fresnel lens (5) form a 40° to 50° angle, suitably an approximately 45° angle.

4. Any of the arrangements according to claims 1 to 3, characterized in that the beam splitter (3) is a wire-grid beam splitter (3a) or a semi-transparent mirror (3b).

5. Any of the arrangements according to claims 1 to 4, characterized in that the image projector (6) includes a mobile phone and/or the image projector (6) includes a polarizer (2b).

6. Any of the arrangements according to claims 1 to 5, characterized in that the switch (1) includes one of the polarizers (2a).

7. Any of the arrangements according to claims 1 to 6, characterized in that the rings (5a, 5b) of different focal lengths are placed next to each other and taking turns in the dual focal Fresnel lens

(5).

8. Any of the arrangements according to claims 1 to 7, characterized in that the arrangement is built into extended reality (XR) glasses.