CN114236854A

CN114236854A - Optical device, optical system, and AR apparatus

Info

Publication number: CN114236854A
Application number: CN202210102699.7A
Authority: CN
Inventors: 谈顺毅
Original assignee: Shanghai Intelight Electronic Technology Co Ltd
Current assignee: Shanghai Intelight Electronic Technology Co Ltd
Priority date: 2021-12-14
Filing date: 2022-01-27
Publication date: 2022-03-25
Also published as: WO2023108949A1

Abstract

The invention provides an optical device, an optical system and an AR device, wherein part of incident light undergoes total reflection at least once in the optical device, at least one part of the surface in the optical device is a surface with focal power, and the focal power of the incident light undergoing total reflection is changed after the incident light enters the surface with focal power. The invention reduces the problem of overlarge thickness and volume of the traditional free-form surface scheme by integrating the traditional optical devices such as a lens and a reflector on a waveguide device, avoids the problems of too low light efficiency, incapability of adjusting image distance in principle and the like of the traditional waveguide scheme, simultaneously accurately calculates the transmission of light rays in the waveguide, and avoids the problems of ghost, parasitic light and the like which are possibly caused by light ray transmission errors after the introduction of the waveguide by controlling the angle and the position of the transmission of the light rays in the waveguide.

Description

Optical device, optical system, and AR apparatus

Technical Field

The present invention relates to the field of AR optics, in particular to optics and optical systems and AR devices.

Background

In recent years AR has gained increasing attention as an important technical direction. Such head-mounted devices impose severe requirements on the bulk weight of the system. The waveguide device has become the mainstream scheme of the next generation of AR device as a light and thin beam combining pupil expanding device. However, both the array waveguide (spliced by a plurality of prisms) and the diffraction waveguide (surface grating or volume grating) achieve the function of combining the expanding pupil and the image by multiple partial transmission and partial reflection of the image light beam in the waveguide, the imaging principle also brings a series of problems to the waveguide device, and the two most prominent problems are low light efficiency (often lower than 10%, and some diffraction waveguides even lower than 1%) and the principle obstacle that the image cannot be adjusted to be far or near (the waveguide design is generally fixed at infinity according to the image, and if the image distance is drawn close, a series of problems such as image splitting and image quality deterioration can be generated).

An optical solution (such as a Birdbath scheme) of the free-curved-surface AR/VR equipment is high in light efficiency, and the scheme does not have the principle obstacle that the image distance cannot be adjusted, but the thickness and the volume of the free-curved-surface AR/VR equipment are difficult to be small, and the obstacle that large-scale popularization is difficult exists.

Disclosure of Invention

In view of the deficiencies in the prior art, it is an object of the present invention to provide an optical device and an optical system and an AR apparatus.

According to the optical device provided by the invention, part of incident light undergoes total reflection at least once in the optical device, at least one part of the surface of the optical device is the surface 201 with the optical power, and the optical power of the incident light undergoing total reflection is changed after the incident light enters the surface 201 with the optical power.

Preferably, the incident light undergoing total reflection is reflected by the surface 201 having optical power.

Preferably, incident light that does not undergo total reflection in the optical device is transmitted from the surface 201 having optical power.

Preferably, the optical power of the light transmitted from the surface with optical power 201 is not changed.

Preferably, at least partial surfaces of the optical devices are parallel to each other, and a total reflection structure for the partial incident light is formed.

Preferably, the surface type of the surface 201 having optical power is any one of a spherical surface, a paraboloidal surface, an ellipsoid surface, a hyperboloid surface, or a combination of any plurality of surface types.

Preferably, the surface 201 with optical power is plated with a reflection increasing film and/or a polarizing film.

Preferably, the optical device comprises a plurality of surfaces 201 having optical power.

Preferably, the surface 201 having optical power is fabricated with a complementary face device for face fitting.

Preferably, one surface of the complementary face device, other than the complementary surface 301 of the complementary face device, which is complementary to the surface with optical power 201, is a plane or a curved surface.

Preferably, the portion of the optical device having the power surface 201 is formed in one process with the other portion by the same mold.

Preferably, the optical device comprises two portions, denoted as device first portion 100, device second portion 200;

the first device part 100 comprises a waveguide device in which light propagates by total reflection;

the second part 200 of the device comprises said device having a surface with optical power.

Preferably, the waveguide device is formed by a waveguide material medium in which light propagates; or

The waveguide device is formed by two dielectric plates, wherein a hollow structure is arranged between the two dielectric plates.

Preferably, light rays corresponding to different fields of view are converged at least once in the optical device.

Preferably, the waveguide device satisfies the condition: such that the number of total reflections experienced by image light rays reflected into the second part 200 of the device from a surface of the waveguide on one side to which the surface 201 having optical power is connected before entering the second part 200 of the device is less than the number of total reflections experienced by image light rays reflected into the second part 200 of the device from a surface of the waveguide on the other side opposite to said one side before entering the second part 200 of the device.

Preferably, the waveguide device satisfies the condition: so that the image light rays reflected into the second part 200 of the device from the surface of the waveguide on the side connected to the surface 201 having optical power undergo the same number of total reflections before entering the second part 200 of the device.

Preferably, the thickness of the waveguide device satisfies the condition: so that the image light rays reflected into the second part 200 of the device from the surface of the waveguide opposite to the surface on the side connected to the surface 201 having optical power undergo the same number of total reflections before entering the second part 200 of the device.

Preferably, a part of the surface of the waveguide device is prepared with a thin film for changing polarization properties, and the polarization properties of the light rays which undergo different total reflection times in the waveguide device or on the surface of the waveguide device are different when the light rays enter the second part 200 of the device.

Preferably, different parts of the optical device are assembled into the same device by gluing or bonding.

Preferably, at least one side surface of the optical device is further glued, bonded or prepared with a curved surface having optical power to correct the vision of the viewer's eye.

Preferably, the optical device further comprises components made of materials with different refractive indexes.

Preferably, the turning component is also included in the optical device.

Preferably, the optical device is glued or bonded from a plurality of parts; wherein:

the glued or bonded surface is plated with a film for changing the property of incident light; and/or

The glued or bonded surfaces are prepared with one or more devices that alter the properties of the incident light (e.g., optically active films or devices, glass slide-like films or devices, etc.).

Preferably, the light properties include: any one or any number of properties of polarization, wavelength, phase, energy.

Preferably, the optical device is glued or bonded from a plurality of parts; wherein: the glued or bonded surface is plated with films with different refractive indexes; and/or one or more devices with different refractive indices are fabricated on the glued or bonded surfaces.

Preferably, the outer side of the optical device is plated with a film, and the film forms a protective layer and/or is attached to the protective layer by the film.

Preferably, the curved surface having optical power is a continuous curved surface, a fresnel surface, or a curved surface-equivalent member that can be modulated.

Preferably, the outer side of the optical device is plated with a thin film (for example, a tempered film, the refractive index of which can be different from or the same as that of the optical device), and a protective layer is formed by the thin film and/or a protective layer is attached by the thin film (for example, the tempered film is attached by using optical cement with low refractive index, and the optical cement becomes the thin film after curing, so that the total reflection characteristic of light in the device is not damaged, and the tempered film prevents the device from being damaged).

The optical system provided by the invention comprises the optical device and further comprises an imaging device;

light output by the imaging device is coupled into the optical device.

Preferably, the imaging device is at least one of LCoS, DMD, LCD, Miro LED, OLED, MEMS Scanner.

Preferably, the optical system further includes at least one of a lens, a mirror, a prism, a grating, a wave plate, an optical rotation plate, a polarizing plate, a filter, a diaphragm, a light source, and an optical fiber.

Preferably, the optical system further comprises a variable device with a function of changing the optical power.

Preferably, the optical system further comprises an adjusting mechanism for changing the spatial position of each component.

According to the invention, the AR equipment comprises the optical device or the optical system.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a new solution, which integrates traditional optical devices such as a lens and a reflector into a waveguide device to reduce the problem of overlarge thickness and volume of the traditional free-curved surface scheme, and couples out light rays in a pupil expanding mode of partial transmission and partial reflection for multiple times, thereby avoiding the problems that the light efficiency of the traditional waveguide scheme is too low, the image distance cannot be adjusted in principle (the light field is not friendly) and the like, simultaneously accurately calculating the propagation of the light rays in the waveguide, and avoiding the problems of ghost, parasitic light and the like possibly caused by light propagation errors after the introduction of the waveguide by controlling parameters such as the angle, the position, the total reflection times and the like of the propagation of the light rays in the waveguide.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic structural view of three portions of an optical device.

Fig. 2 is a schematic diagram of the propagation path of light in an optical device.

Fig. 3 is a schematic structural diagram of the optical device with two sides coupled in and out respectively through curved surfaces.

Fig. 4 is a schematic structural diagram of an optical device having a plurality of curved surfaces.

Fig. 5 is a schematic diagram of the structure between the parts of the optical device having a plurality of curved surfaces before combination.

Fig. 6 is a schematic view of an optical device having a plurality of curved surfaces integrally formed.

Fig. 7 is an optic having a vision correcting curved surface.

Fig. 8 is a schematic diagram of a structure in which the first portion of the device includes lenses of different refractive indices.

FIG. 9 is a schematic diagram of a structure including a transition scheme.

FIG. 10 is a schematic diagram of a structure comprising another transition scheme.

Fig. 11 is a schematic diagram of an optical device formed of an upper waveguide and a lower waveguide.

Fig. 12 is a schematic diagram of an optical device composed of an upper waveguide and a lower waveguide having a protective layer on the outer side.

Fig. 13 is a schematic view of a structure in which the positions of the portion having the curved surface and the planar waveguide portion are different from each other.

Fig. 14 is a schematic diagram of the structure of layers or devices having different refractive indices in the device.

The figures show that:

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1

The invention provides an AR device, such as AR glasses or an AR helmet, and the AR device comprises an optical device and is applied to an AR display system. As will be understood by those skilled in the art, Mixed Reality (MR) is an AR, and a virtual object in an MR scene usually has a response relationship with a real object, and is understood to be an interesting AR.

As shown in fig. 1, the optical device includes two portions, which are referred to as a first device portion 100 and a second device portion 200. The device first portion 100 comprises a waveguide device in which light propagates by total reflection. In fig. 1, the first part 100 of the device is a planar waveguide 101 with parallel surfaces, a length and a width of 35 × 40mm, and a thickness of 5mm, i.e. a waveguide device, preferably made of a waveguide dielectric material (e.g. plastics such as EP9000, E48R, or optical glass with a high refractive index, etc.), in which light propagates; in a variation, the waveguide device is formed by two dielectric plates (with a polarizing film or a reflective film coated on the surface), wherein a hollow structure is formed between the two dielectric plates, and light propagates through the hollow structure. The device second part 200 (18 x 40mm in length and width and 5mm in thickness at the interface with the device first part 100) comprises a part with curvature, the device second part 200 comprises a surface 201 (18 x 18mm in length and width) with optical power, and the surface type of the surface 201 with optical power is any one of a spherical surface, a paraboloid, an ellipsoid, a hyperboloid or other curved surface which can be characterized by mathematical expressions or a combination of any plurality of surface types; the incident light which undergoes total reflection enters the surface 201 with focal power, the focal power is changed, and the incident light is reflected by the surface 201 with focal power and then is coupled out of the optical device; incident light that does not undergo total reflection in the optical device is transmitted from the surface 201 having optical power, and the optical power of light transmitted from the surface 201 having optical power is not changed. The refractive indices of the second portion 200 of the device and the waveguide 101 of the first portion 100 of the device are similar (similar means that they differ by less than 0.1, for example, the refractive index difference is less than 0.1) or identical. For example, both the waveguide and the second part are made of EP9000 material. The thickness of the interface of the second device part 200 and the first device part 100 corresponds to the thickness of the waveguide 101 of the first device part 100, said surface 201 with optical power can be regarded as a coupling-out curve, or the second device part 200 can be regarded as a coupling-out member. The device second part 200 is assembled with the waveguide 101 of the device first part 100 by a gluing or bonding process into a device. In a variation, the waveguide device in which the light propagates by total reflection may be, for example, a wedge-shaped or tapered waveguide, so that the incident angle of the light with the surface of the waveguide changes every time the light propagates by total reflection in the waveguide (the incident angle of the light, which intersects with the normal of the surface, decreases every time the light propagates from the thick end to the thin end of the waveguide, and increases otherwise), thereby increasing the control parameter for the propagation of the light in the waveguide, and making the optical design more flexible.

In a preferred embodiment, the optical device further comprises a complementary face portion 300 (25 x 40mm long and wide), as shown in fig. 1, there being a pair of complementary surface faces between complementary face portion 300 and device second portion 200, i.e. between complementary surface 301 of complementary face portion 300 and surface 201 having optical power of device second portion 200. The complementary planar portion 300 is bonded (using glue having a similar or the same refractive index) or glued to the second portion 200 of the device. The refractive index between the complementary face portion 300 and the second portion 200 of the device is similar or identical. For example, the complementary contoured portion and the curved portion are both made from EP9000 material. In a preferred embodiment, the refractive indices of the complementary facet portion 300, the second device portion 200, and the waveguide 101 of the first device portion 100 are similar or identical. The thickness of the complementary facet portion 300 glued or bonded to the device second portion 200 corresponds to the waveguide 101 of the device first portion 100. The complementary face-type component 300 has an outwardly facing face 302, which outwardly facing face 302 is planar in fig. 1. In fig. 7, the outwardly facing surface 302 of the complementary surface element 300 is curved to provide vision correction.

As shown in fig. 2, the image light enters the waveguide from the waveguide 101 side of the device first portion 100, undergoes multiple total reflections, and reaches the interface between the waveguide and the portion having curvature of the device second portion 200, that is, the interface between the waveguide 101 of the device first portion 100 and the device second portion 200.

In an AR display system, the upper surface of the waveguide 101 in fig. 2 is the outer surface of the waveguide, or referred to as the front surface, or also referred to as the distal surface, i.e. the surface of the waveguide away from the AR wearer's eye, and the lower surface of the waveguide 101 in fig. 2 opposite the upper surface, is the inner surface of the waveguide, or referred to as the rear surface, or also referred to as the proximal surface, i.e. the surface of the waveguide close to the AR wearer's eye.

The surface 201 of the second part 200 of the device having the optical power is connected to the upper surface of the waveguide 101. The number of total reflections experienced within the waveguide 101 before entering the second part 200 of the device is the same between all light rays whose last total reflection surface is the upper surface of the waveguide 101 within the waveguide 101, and the number of total reflections experienced within the waveguide 101 before entering the second part 200 of the device is the same between all light rays whose last total reflection surface is the lower surface of the waveguide 101 within the waveguide 101. The light is, for example, an image light, such as an image light in an AR device.

The number of total reflections that the image light rays undergo before each of all the light rays whose last total reflection surface is the upper surface of the waveguide 101 in the waveguide 101 is one less than the number of total reflections that the image light rays undergo before each of all the light rays whose last total reflection surface is the lower surface of the waveguide 101. After the image light rays with the last total reflection surface being the upper surface of the waveguide 101 enter the second part 200 of the device, the image light rays undergo total reflection again on the plane 203 of the second part 200 opposite to the surface 201 with focal power, are reflected by the surface 201 with focal power, exit from the device, and enter the eyes of a viewer. The image light rays with the last reflecting surface being the lower surface of the waveguide 101 enter the second part 200 of the device, are directly reflected by the lower surface of the waveguide to the surface 201 with the power, and exit the device after being reflected by the surface 201 with the power, entering the eyes of the viewer. In order to control the number of reflections of the light, the above conditions can be satisfied by adjusting the thickness of the waveguide and the properties of the input light (such as the angle and the position in the waveguide), and the image light corresponding to the field of view can be focused once inside the waveguide.

The surface 201 with optical power in this embodiment is a curved surface, which may be designed like a paraboloid, and the focusing position of the image light rays of each field in the waveguide 101 is equivalent to the vicinity of the focus of the paraboloid. In other embodiments, the curved surface may also be designed as a rotating hyperbolic curve, an ellipsoid, or a complete free-form surface.

A polarizing film may be plated on the surface 201 with optical power of the second device part 200 or the complementary surface 301 of the complementary surface type part 300, so as to transmit the incident light with the polarization direction P and totally reflect or partially reflect the incident light with the polarization direction S; in a variant, the incident S light is partially reflected, for example 50% reflected. The image light has a polarization direction S and is reflected and the power changes after entering the surface 201 with power, and finally the viewer will view an image at a distance from himself (e.g. infinity, 2 m in front of the eye or 0.5 m in front of the eye, the image distance can be modulated by controlling the input light).

The polarizing film may be plated on the surface 201 having optical power, and the complementary surface 301 need not be plated. Alternatively, the polarizing film may be plated on the complementary surface 301, and the surface 201 having optical power does not need to be plated. After the complementary surface type part 300, the second part 200 of the device and the waveguide 101 are assembled, the appearance of the whole device is the same as that of a whole planar waveguide.

After external environment light enters the optical device, P light is transmitted through a part of the optical device, which comprises the surface 201 with the focal power and the coating, S light is totally reflected or partially reflected, the transparency can be controlled by controlling the transmittance and the reflectance of the S light through the coating, and the external environment light equivalently penetrates through a piece of flat glass and can be clearly seen by human eyes due to the fact that the refractive indexes of the parts of the optical device are similar or identical. Since the image light is S light, if a polarizing film layer with reflectivity of greater than 95% of the S light is coated, the loss of light propagating in the waveguide is taken into account, the efficiency of the optical device for the incident light will reach about 90%, which is much higher than that of the existing array or diffraction type waveguide combined by the multiple transmission reflection principle, and for the external ambient light, it is equivalent to a sunglass with transmittance of about 50%, and of course, the reflectivity of the S light can also be reduced, for example, the reflectivity of the S light is 50% and the transmittance of the optical device for the ambient light is increased by 50% transmission.

For the waveguide 101, a polarization or transflective coating may be added on the surface to make the transmittance of the waveguide 101 to the external ambient light close to or equal to that of the surface 201 with power, so that the external ambient light viewed by the viewer through the waveguide 101 is close to or consistent with the ambient light viewed through the curved surface portion formed by the surface 201 with power. Or the surface of the glass can be coated with an antireflection film to increase the ambient light transmittance.

In some embodiments, light corresponding to different fields of view is collected at least once in the optical device. As shown in fig. 2, the convergence occurs in the first part 100 of the device, and in a variation, the convergence may also occur at a position near the focal point of the curved surface 201 having optical power.

In this embodiment, as shown in fig. 3, in the portion where the image light is coupled into the waveguide, a curved member 400 similar to the curved surface for coupling the image out to the human eye may be used, and the curved member 400 including a surface having optical power may be glued or bonded to the other side of the waveguide 101. The curved surface part 400 on the other side of the waveguide 101 may be a total reflection coating (e.g., a metal film) to increase the light utilization rate; or in some designs with a short distance from the coupling-in part to the coupling-out part, a polarization coating can be used, and if the coupling-out part is glued with an element with the same surface type complementary refractive index, the optical device is in a complete planar waveguide configuration, so that part of the ambient light with a large angle can be normally viewed through the optical device.

As shown in fig. 1 and 3, the optical device may be manufactured by first manufacturing a planar waveguide 101, a second part 200 of the device coupled out on one side of the waveguide 101, a complementary surface-type part 300, a curved surface part 400 coupled in on the other side of the waveguide 101, and an element attached to a reflective part of the curved surface part 400, respectively, and then assembling the components into a complete device through a gluing/bonding process after coating films on the components.

As shown in fig. 6 and 7, the waveguide 101 and the coupled-in curved reflective portion and the coupled-out curved reflective portion may be a single component formed by one-step molding in the same mold, and the components with the complementary curved reflective portions are assembled by gluing/bonding after coating to form the complete device.

In this embodiment, the imaging device in the AR system or the like employs an LCoS, and image light output from the LCoS is coupled into the optical device as linearly polarized light having a polarization direction S after passing through a PBS device (or a polarization dependent device such as a polarizing film).

The imaging device can also adopt Micro LED or OLED and other devices, and compared with LCOS, DMD and other devices, a light source, PBS, TIR and other devices can be omitted, and the size is further reduced. When image light emitted by devices such as Micro LEDs or OLEDs is non-linearly polarized, devices such as a polarizing plate or a wave plate can be additionally arranged in a light path to modulate the image light into linearly polarized light, and then the linearly polarized light is input into the optical device comprising the waveguide 101. Or a semi-transparent and semi-reflective (or certain transmittance and certain reflectivity) or a film reflecting at a specific angle can be plated on the image coupling-out curved surface, so that the waste of light energy of the non-polarized imaging device is avoided.

Other lenses or mirrors can be added in the system to modulate the light output by each pixel point on the imaging device into parallel light or nearly parallel light of different angles to be coupled into the waveguide, and the light is focused on an outcoupling surface in the second part 200 of the device, namely near the focus of the surface 201 with optical power, through the incoupling curved surface of the curved surface component 400, and finally is output by the outcoupling surface to be imaged.

In the whole system, a variable curved surface (such as a liquid crystal lens, a liquid lens, a spatial light modulator adopting phase modulation and the like) can be added, so that the function of changing the focal power of the system in real time is realized, different electric signals can be applied to the optical device through a control system, the image finally observed by an observer is modulated to different imaging distances, and the light field/holographic display function is realized. Meanwhile, the variable device can compensate the problems of near/far vision, astigmatism and the like of eyes of different viewers. The adjustment function may be achieved by adding an adjustment mechanism (e.g., a micro motor) to the system to change the position between the optical components.

In one embodiment, the coupling-in curved surface may be replaced by a planar reflective spatial light modulator using phase modulation, and the spatial light modulator is attached to the surface of the waveguide 101, and may simulate any curved surface shape within a certain parameter range, thereby implementing real-time dynamic modulation of the coupled-in image light, implementing light field display, and compensating for the problems of myopia of the eyes of the viewer.

In one embodiment, a spatial light modulator may also be used as an imaging device in conjunction with a computed hologram generated by the control system to simultaneously modulate the imaging distance and compensate for optical aberrations. In the scheme, the spatial light modulator simultaneously completes the functions of imaging and modulating optical aberration, an additional variable curved surface device is not needed, and the number of components can be reduced.

In a variation of this embodiment, waveguide 101 may be formed using two parallel dielectric plates (no other material between the two plates) coated with a polarizing film on the inside to completely reflect the incident S-direction image light, while the ambient P-light may be transmitted through the two dielectric plates unaffected by the incident S-direction image light. This has the advantage that the weight of the device can be reduced. In this embodiment, the coupled curved members may also be formed using a piece of curved lens plus flat plate instead of the specific structure of the second portion 200 of the device of fig. 1 to form the second portion 200 of the device, thereby further reducing weight.

On the outside of the whole device, a protective layer such as a tempered coating or thin tempered glass may be further added to protect the device from being easily damaged. The four sides of the device can be coated with light-absorbing coatings or black materials for filtering/absorbing stray light.

As shown in figure 7, the side of the optical device facing the external environment can be added with a lens with optical power, so that the optical device becomes a pair of glasses with optical power, and a user with myopia can see the external environment light clearly. The lens may also be added on the side facing the viewer so that the viewer sees the external environment while also seeing image light based on the actual distance modulation (without compensation for the viewer's vision).

In one embodiment, a lens-like device made of materials with different refractive indices may also be added to the waveguide device, as shown in fig. 8. The waveguide is divided into two sections, namely a first waveguide section 1011 and a second waveguide section 1012, the intersecting surface shape of each section and a lens 1013 positioned between the two sections of waveguides is complementary with the surface of the lens, the waveguide is made of OKP-A2 material, the lens is made of PMMA material, and the lens is glued on the two sections of waveguides to form a whole. This has the advantage that part of the optics can be incorporated into the waveguide, further reducing the system volume.

In one embodiment, the turning component 500 may be added, the waveguide is made into a special shape such as L-shape (one-time turning) or Z-shape (two-time turning) (as shown in fig. 9 and 10, fig. 9 and 10 are two different turning devices, respectively, fig. 9 can fold the optical path into L-shape, a part of the folded optical path can be integrated into the spectacle frame of the spectacles, and the other part can be used as a lens, the turning device of fig. 10 can fold the waveguide into L-shape, and the waveguide can still maintain a single planar configuration in the viewing direction of the user, similar to a single planar lens, and the two different turning devices can be applied in different embodiments or can be applied in combination in the same embodiment), thereby increasing the flexibility of the appearance design. The turning member 500 may be a prism with a planar reflecting surface or a prism with a curved reflecting surface, and connects two segments of waveguides by gluing/bonding. Or the optical waveguide can be manufactured by integrally manufacturing the mold and the waveguide and then manufacturing corresponding thin films (a reflecting film, a metal reflecting film, a polarization reflecting film and the like) on corresponding surfaces.

Example 2

Embodiment 2 is an embodiment in which a plurality of curved surfaces are arranged in sequence, and is a variation of embodiment 1.

As shown in fig. 4, an optical device includes a plurality of surfaces 201 with different surface types and with optical power, which are arranged in sequence on one side of the waveguide 101 in the extending direction of the waveguide 101, in this example, three surfaces 201 with optical power are included, and the included angle formed by the normal of each point on the curved surface formed by the surfaces 201 with optical power and the normal of the upper surface of the waveguide 101 increases in the direction away from the waveguide 101. The thickness of the curved surface formed by the surface 201 with the power is smaller than that of the waveguide 101, and the image light rays reflected from the lower surface of the waveguide 101 and entering the surface with the power (i.e. the surface 201 with the power) will be directly reflected by the curved surface and enter the eyes of the observer, while the image light rays reflected from the upper surface of the waveguide 101 and entering the curved surface part will first undergo total reflection at a plane 203 corresponding to any one of the three curved surface parts and opposite to the surface 201 with the power and then enter any curved surface, and then enter the eyes of the observer after being reflected by the curved surface. In this example the thickness of the curved surface is 1.5mm and the thickness of the waveguide is 3 mm. The benefit of using this multiple curved surface scheme is that the overall thickness of the device can be further reduced and the out-coupling area can be increased (increasing the eyebox and field of view of the system).

As shown in fig. 5, the optical device can be manufactured by processing the waveguide and the curved surfaces (mold or machining), plating the required plating films on the surfaces, and then assembling the optical device into a complete device by gluing or bonding.

As shown in fig. 6, the optical device may be manufactured by integrally manufacturing the waveguide and the curved surfaces (for example, by one-step mold release molding in a mold), or by integrally manufacturing elements complementary to the curved surfaces, and then bonding the two parts after coating to assemble the device. In this manufacturing process, the side of the complementary element facing the ambient light may also be made curved with a certain power, i.e. the outward facing surface 302, to compensate for the near/far vision, astigmatism, etc. of the viewer's eye, as shown in fig. 7. While the example shown in fig. 6 is a variation of fig. 7, the variation being that the outwardly facing face 302 in fig. 6 is planar.

In one embodiment, a portion of the surface of the waveguide is fabricated with a thin film that changes polarization properties that differ when light rays that undergo different total reflection times within or at the surface of the waveguide enter the second portion 200 of the device. Specifically, a film layer capable of changing polarization characteristics is coated (or bonded) on the upper surface or the lower surface of the waveguide, so that the polarization directions of the light rays with different total reflection times on a certain surface (for example, the lower surface) in the waveguide are different (for example, the polarization direction changes by 90 degrees every time the light ray is reflected once on the coated surface, so that the polarization direction of the light ray with even number of reflection times on the lower surface is S, and the polarization direction of the light ray with odd number of reflection times on the lower surface is P), when the light ray enters the curved surface portion (i.e., the second part 200 of the device), the light ray with polarization direction S will be reflected by the curved surface and coupled out of the device, while the light ray with polarization direction P will pass through the curved surface portion and then undergo total reflection once to reach the surface (i.e., the opposite plane 203) where the curved surface portion is connected with the lower surface of the waveguide, and the same film layer for changing polarization characteristics is also prepared on the opposite plane 203, the P light can be converted into S light, and the S light is reflected by the curved surface part after being totally reflected again and is coupled out of the device. This has the advantage of providing new characteristics to control the light so that it remains uniformly reflected, allowing the waveguide to be made thinner, with a larger field of view and EYEBOX.

Example 3

The optical device in embodiment 3 is composed of an upper device and a lower device (as shown in fig. 11), and the upper device and the lower device are an upper waveguide and a lower waveguide, respectively. The upper and lower portions have the same refractive index, and are glued together by a gluing process, a thin film or a device (such as a liquid crystal layer) with a light rotation effect is prepared on an interface 700 of the upper and lower portions of the waveguide, when linearly polarized light first passes through a middle light rotation layer from the lower waveguide to enter the upper waveguide, the polarization direction of the linearly polarized light in the upper waveguide is S direction, the linearly polarized light is totally reflected (or reflected by a curved surface device) by the upper waveguide, then passes through the middle light rotation layer to enter the lower waveguide, and then passes through the middle light rotation layer again to enter the upper waveguide for the second time, and then the polarization direction of the linearly polarized light is changed into P direction. In other words, the light rays that undergo odd reflections on the entire top surface of the device after the top-bottom combination have the S-direction polarization direction in the upper waveguide, and the light rays that undergo even reflections have the P-direction polarization direction in the upper waveguide.

The surface of the curved surface part with focal power in the device is plated with a polarization reflection film, and when light with the polarization direction of S direction is incident on the surface, the light is reflected from the surface to form an image; when light with the polarization direction in the P direction enters the surface, the light penetrates through the surface, enters the lower waveguide after undergoing primary total reflection on the upper surface, is changed into the S direction when being incident on the curved surface again after being totally reflected by the lower surface, and is reflected and imaged by the curved surface. This has the advantage that more control can be added to achieve the purpose of controlling the beam to exit at a certain position on the curved surface and to achieve that the light rays experience the same number of reflections at a particular surface within the waveguide, e.g. in this case all exit after an odd number of reflections at the upper surface (including the reflections coupled into the curved surface).

In a modification of the above embodiment, the optical rotation device 700 is not located at the same position as the portion having the curved surface and the planar waveguide portion, as shown in fig. 13. This has the advantage that light that is reflected odd times by part of the upper surface does not cause a change in polarization direction due to more than one reflection at the lower surface, resulting in part of the energy being coupled out of the device from the wrong location.

In a variation of the above embodiment, layers or devices with different refractive indices may also be added to the device, as shown in fig. 14, n₁、n₂、n₃The thickness of the formed film layer is 5um, n₁、n₂N are different from each other, thereby further increasing the means for distinguishing light rays.

In the above embodiments, the optical rotation layer may be replaced by an optical film or device such as a glass slide having similar functions, so that the light rays reflected by odd and even numbers on the upper or lower surface of the device have different polarization properties (direction, circular polarization/linear polarization, etc.), thereby achieving the purpose of distinguishing and controlling the light rays reflected by different numbers of times. For example, 1/4 glass plate or film with similar function is made on the lower part of the device (as shown in fig. 11), the linear polarization P light inputted from the upper part will be converted into the left-handed or right-handed optical rotation close to circular polarization by 1/4 glass plate, and after going through the reflection of the bottom part, the input light of left-handed or right-handed rotation will be changed into the circular polarization of right-handed or left-handed rotation, and after passing through 1/4 glass plate again, will be modulated into S light to return to the upper part. On the other hand, the S light input from the upper part is reflected twice by the 1/4 glass plate and the lower part to be modulated into P light. In other words, the light has two states of S and P on the upper portion of the device, and the off-linear polarization states that undergo different reflection times are different, so that only the light reflected by the corresponding surface for a set number of times (odd or even) can be coupled out of the device by the curved surface portion (see fig. 11), and the rest of the light can be coupled out of the device by the curved surface portion after the surface undergoes another reflection.

In the above embodiments, the optical rotation layer or the glass slide layer may be replaced with a film or a device for changing other properties of light, so that the properties (phase, wavelength, polarization, energy, etc.) of light reflected by odd and even numbers of times on the upper or lower surface of the device are different, thereby achieving the purpose of distinguishing and regulating light reflected by different numbers of times.

In a variation of the above embodiment, a polarization extinction layer (e.g., a polarizer or a film that functions the same) may also be added to the device to eliminate residual stray light that is not fully converted in optical properties (e.g., polarization direction).

The optical rotation device, the glass slide device and the depolarizing device in the above embodiments can be used alone or can be combined and integrated in the device.

On the outer sides of all the devices, a protective layer (as shown in fig. 12, a curved waveguide is used in this example, and the curved waveguide can also be applied to other examples) can be added, for example, a film layer with a lower refractive index than the device is prepared on the outer side of the device, and the device surface is included while the total reflection propagation of light rays in the device is not damaged. And a film layer (a toughened layer) with high hardness can be prepared outside the low-refractive-index film layer to play a further protection role.

The surface of the device can be plated with an antireflection film layer to improve the transmittance of ambient light.

The upper surface or the lower surface of the above device can be further attached with a component with focal power, so as to compensate the vision defects (myopia, hyperopia, astigmatism, etc.) of the viewer, the component with focal power can be a common spectacle lens, or a lens similar to a fresnel lens, or a component with dynamically adjustable focal length, such as a variable lens (a liquid crystal lens, a liquid lens, etc., the liquid crystal lens is a plane, and can be equivalent to a curved surface with focal power through phase modulation), and the input signal is dynamically adjusted through a control system.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims

1. An optical device, characterized in that part of the incident light undergoes at least one total reflection in the optical device, at least a part of the surface of the optical device being a surface (201) having optical power, the optical power of the incident light that undergoes total reflection being changed upon incidence on the surface (201) having optical power.

2. The optical device according to claim 1, characterized in that the incident light undergoing total reflection is reflected by the surface with optical power (201).

3. The optical device according to claim 1, characterized in that incident light that does not undergo total reflection in the optical device is transmitted from the surface (201) having optical power.

4. The optical device according to claim 3, wherein the optical power of the light transmitted from the surface (201) having optical power is not changed.

5. The optical device according to claim 1, wherein at least some of the surfaces of the optical device are parallel to each other, forming a total reflection structure for the portion of the incident light.

6. The optical device according to claim 1, wherein the surface type of the surface (201) having optical power is any one of a spherical surface, a paraboloidal surface, an ellipsoid surface, a hyperboloid surface or a combination of any plurality of surface types.

7. The optical device according to claim 1, characterized in that the surface (201) with optical power is plated with a reflection-increasing film and/or a polarizing film.

8. The optical device according to claim 1, characterized in that it comprises a plurality of surfaces (201) having optical power.

9. The optical device according to claim 1, wherein the surface (201) with optical power is prepared with a complementary face device with face fitting.

10. An optical device according to claim 1, wherein one surface of the complementary face device other than the complementary surface (301) complementary to the surface with optical power (201) is planar or curved.

11. The optical device according to claim 1, characterized in that the part of the optical device having the power surface (201) is machined in one piece with the other part by the same mould.

12. The optical device according to claim 1, characterized in that it comprises two portions, respectively a first device portion (100), a second device portion (200);

the first part (100) of the device comprises a waveguide device in which light propagates by total reflection;

a second part (200) of the device comprises the device with the surface having optical power.

13. The optical device according to claim 12,

the waveguide device is formed by waveguide material media in which light rays propagate; or

14. The optical device of claim 1, wherein light rays corresponding to different fields of view are converged at least once in the optical device.

15. The optical device of claim 12, wherein the waveguide device satisfies the condition: such that the number of total reflections experienced by image light rays reflected into the second part (200) of the device from a surface of the waveguide on one side to which the surface (201) having optical power is connected before entering the second part (200) of the device is less than the number of total reflections experienced by image light rays reflected into the second part (200) of the device from a surface of the waveguide on the other side opposite to said one side surface before entering the second part (200) of the device.

16. The optical device of claim 12, wherein the waveguide device satisfies the condition: so that the image light rays reflected into the second part (200) of the device from the surface of the waveguide on the side connected to the surface (201) having optical power undergo the same number of total reflections before entering the second part (200) of the device.

17. The optical device of claim 12, wherein the waveguide device satisfies the condition: so that image light rays reflected into the second part (200) of the device from a surface of the waveguide opposite to the surface on the side connected to the surface (201) having optical power undergo the same number of total reflections before entering the second part (200) of the device.

18. An optical device according to claim 12, characterized in that part of the surface of the waveguide is provided with a thin film that changes the polarization properties of light rays that undergo different total reflection times in or at the surface of the waveguide when entering the second part (200) of the device.

19. An optical device according to claim 1, characterized in that different parts of the optical device are assembled into the same device by gluing or bonding.

20. The optical device of claim 1, wherein at least one side surface of the optical device is further glued, bonded or prepared with a curved surface having optical power to correct the vision of the viewer's eye.

21. The optical device of claim 1, further comprising components fabricated from materials having different refractive indices.

22. The optical device of claim 1, further comprising a turning member.

23. The optical device of claim 1, wherein the optical device is glued or bonded from multiple parts; wherein:

The glued or bonded surfaces are prepared with one or more devices that modify the properties of the incident light.

24. The optical device of claim 23, wherein the light ray properties comprise: any one or any number of properties of polarization, wavelength, phase, energy.

25. The optical device of claim 1, wherein the optical device is glued or bonded from multiple parts; wherein: the glued or bonded surface is plated with films with different refractive indexes; and/or one or more devices with different refractive indices are fabricated on the glued or bonded surfaces.

26. The optical device according to claim 1, wherein the outer side of the optical device is coated with a film, and the film forms a protective layer and/or is attached to the protective layer by the film.

27. The optical device of claim 20, wherein the curved surface having optical power is a continuous surface, a fresnel surface, or a surface-equivalent element that can be modulated.

28. An optical system comprising an optical device according to any one of claims 1 to 27, further comprising an imaging device;

light output by the imaging device is coupled into the optical device.

29. The optical system of claim 28, wherein the imaging device is at least one of an LCoS, a DMD, an LCD, a Miro LED, an OLED, a MEMS Scanner.

30. The optical system of claim 28, further comprising at least one of a lens, a mirror, a prism, a grating, a wave plate, an optical rotation plate, a polarizer, a filter, a diaphragm, a light source, and an optical fiber.

31. The optical system of claim 28, further comprising a variable device having a function of varying the optical power.

32. The optical system of claim 28, further comprising an adjustment mechanism for changing the spatial position of the components.

33. An AR device comprising the optical device of any one of claims 1 to 27, or comprising the optical system of any one of claims 28 to 32.