CN115469459A - Near-to-eye display device - Google Patents

Abstract

The embodiment of the application relates to the technical field of display and provides near-to-eye display equipment. The near-eye display device includes: an image source for emitting image light; a focusing assembly for changing a focal length of the image light; a coupling structure located between the image source and the focusing assembly for optically coupling the image into the focusing assembly; the optical waveguide is positioned on the light emergent side of the focusing component; and a coupling-out structure located in a light-exiting region of the optical waveguide. The image light is transmitted in the optical waveguide after passing through the focusing assembly and is coupled out of the optical waveguide from the coupling-out structure.

Description

Near-to-eye display device

Technical Field

The application relates to the technical field of display, in particular to a near-to-eye display device.

Background

At present, near-eye display devices based on Augmented Reality (AR) technology have a problem that users are prone to fatigue and even dizzy.

Disclosure of Invention

The embodiment of the application provides a near-eye display device. The near-eye display device includes:

an image source for emitting image light;

a focusing assembly for changing a focal length of the image light;

the coupling structure is positioned between the image source and the focusing assembly and is used for optically coupling the image into the focusing assembly;

the optical waveguide is positioned on the light emitting side of the focusing component; and

the coupling-out structure is positioned in the light emitting area of the optical waveguide;

wherein the image light propagates in the optical waveguide after passing through the focusing assembly and is coupled out of the optical waveguide from the coupling-out structure.

Because foretell near-to-eye display device sets up through the light path at the image source outgoing image light the focusing subassembly can change the focus of the image source outgoing image light for the user can adjust the virtual image that the image source formed to the distance of people's eye according to the demand, make the virtual image that people's eye sees be far and near changeable, and not be in fixed state of focusing all the time, make the ciliary muscle of people's eye can move thereupon, thereby alleviate the tired sense of people's eye, avoid dizzy production, reach relaxed purpose. In addition, because foretell near-to-eye display device can change the focus of image light through the focusing subassembly, can directly wear near-to-eye display device to the user of vision difference, and need not to wear myopia glasses earlier and wear near-to-eye display device again, has solved the inconvenient problem of myopia person's dress, has promoted the comfort level of wearing.

Drawings

Fig. 1 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.

Fig. 2 is a schematic optical path diagram of the near-eye display device of fig. 1.

Fig. 3 is a schematic structural diagram of the focusing assembly in fig. 2.

Fig. 4A and fig. 4B are schematic diagrams of optical paths of a position-adjustable lens at different positions in an embodiment of the present application.

FIG. 5 is a schematic diagram of an imaging principle of a superlens in another embodiment of the present application.

Description of the main element symbols:

near-to-eye display device 100

Frame for mirror 10

Temples 20

Lens 30

Image source 40

Coupling-in structure 50

Focusing assembly 60

Housing 61

Light incident hole 611

Light-emitting hole 612

First light directing element 62

Lens group 63

First lens 631

Second lens 632

Third lens 633

Superlens 634

Vector 6341

Micro-nano structure 6342

Second light directing element 64

Knob 65

Optical waveguide 70

Coupling-out structure 80

Image light L1

Stray light L2

Right eye E

Distance D

Optical axis X

Detailed Description

Augmented Reality (AR) technology refers to a technology in which a virtual scene on a screen can be combined and interacted with a real scene of the real world by performing position and angle calculation on an image of an image source (also called an optical machine or a projector) and adding an image analysis technology.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

Fig. 1 is a schematic structural diagram of a near-eye display device 100 according to an embodiment of the present application. As shown in fig. 1, near-eye display device 100 is configured in the form of glasses (e.g., AR glasses). In other embodiments, the near-eye display device 100 may also be configured in the form of a helmet or a visor, which is not limited herein.

Specifically, the near-eye display apparatus 100 includes a frame 10, temples 20 connected to both sides of the frame 10, two lenses 30 provided on the frame 10, and a focusing assembly 60 provided on the frame 10. In the embodiment shown in fig. 1, both lenses 30 are optical waveguides 70.

Fig. 2 is a schematic optical path diagram of near-eye display device 100 of fig. 1. Fig. 2 illustrates an example of a lens 30 for the right eye E of a person. The lens 30 corresponding to the left eye of the person of the near-eye display device 100 is symmetrically arranged with the lens 30 corresponding to the right eye E of the person in fig. 2, and has the same structure.

As shown in fig. 2, near-eye display device 100 also includes an image source 40, a coupling-in structure 50, and a coupling-out structure 80.

Specifically, the image source 40 is used to emit image light L1. The image source 40 may be provided at the temple 20 shown in fig. 1. When the near-eye display apparatus 100 is used to implement AR display for both lenses 30 of both eyes of a person, the number of image sources 40 may be two, and the two image sources 40 are respectively disposed at the two temples 20. Alternatively, the two image sources 40 are positioned at the frame 10 corresponding to the bridge of the nose. Since the image source 40 protrudes from the frame 10 when it is disposed at the corresponding bridge of the nose, which is not good for the beauty of the AR glasses, the image source 40 is preferably disposed at the temple 20.

The two lenses 30 correspond to the left and right eyes of the user, respectively, when the user wears the near-eye display device 100. The two image sources 40 located at the temple 20 emit light with image information to provide virtual images to the two lenses 30 (or the two optical waveguides 70), respectively.

Specifically, the two lenses 30 (or the two light guides 70) are transparent and can directly transmit light of the real world, and a user can see a real image of the real world through the two lenses 30. When the user wears the near-eye display device 100, the near-eye display device 100 can superimpose the virtual image and the real world, so that the user sees the image formed by combining the real image and the virtual image, and the sensory experience beyond reality is achieved.

For example, the near-eye display device 100 may enable a user to experience virtual shopping. When the user wears the near-eye display device 100, the two lenses 30 transmit an image of the real world to the user's eyes, for example, the real world is a shop. At this point, the user sees a real image of the store. In addition, the image source 40 can provide a virtual image to the optical waveguide 70, for example, the virtual image is related information of the goods (e.g., the lifetime, the production place, the composition, etc. of the goods). At this point, the light guide 70 conveys the virtual image provided by the image source 40 to the user, who sees the image as information about a virtual good in a real store.

In one embodiment, the image source 40 is any one of an Organic Light-Emitting Diode (OLED) Display, a Micro inorganic Light-Emitting Diode (Micro LED) Display, a Liquid Crystal Display (LCD), a Liquid Crystal on Silicon (LCoS) Display, a Digital Micro-mirror Device (DMD), and a Laser Beam Scanner (LBS). The light emitted by image source 40 may be visible light, which may be a single wavelength light, or may include multiple wavelength bands of light (e.g., red, blue, and green).

The incoupling structure 50 is located between the image source 40 and the focusing assembly 60. The incoupling structure 50 is used for incoupling the image light L1 emitted from the image source 40 into the focusing assembly 60. The optical waveguide 70 is located on the light exit side of the focusing assembly 60. The incoupling structure 50 is, for example, an incoupling grating. The incoupling grating is capable of diffracting the image light L1 incident thereon and causing the diffracted light to enter the focusing assembly 60.

The coupling-out structure 80 is located in a light-exiting region (also referred to as a coupling-out region) of the optical waveguide 70 and is used for coupling out the image light L1 in the optical waveguide 70. The outcoupling structures 80 are, for example, outcoupling gratings. After the image light L1 propagating in the optical waveguide 70 is diffracted by the coupling-out grating, the light which does not satisfy the total reflection condition of the optical waveguide 70 is coupled out of the optical waveguide 70 and enters human eyes to be perceived. In this process, part of the stray light L2 is coupled out in a direction away from the human eyes.

The optical waveguide 70 is located on the light exit side of the focusing assembly 60. The focusing assembly 60 is used to change the focal length of the image light L1. Referring to fig. 1 and 3, the focusing assembly 60 includes a housing 61 and a knob 65 disposed on the housing 61. The housing 61 is disposed on the frame 10 to avoid obstructing the user's view of the real world through the lenses 30. The case 61 may be provided in the frame 10 or on the surface of the frame 10, and the knob 65 may be provided on the outer surface of the case 61 and protrude from the side of the frame 10 for the user's convenience in operation.

As shown in fig. 3, the focusing assembly 60 further includes a first light directing element 62, a second light directing element 64, and a lens group 63. The second light directing element 64 is spaced from the first light directing element 62. The lens group 63 is located between the first light directing element 62 and the second light directing element 64. The first light guiding element 62, the second light guiding element 64 and the lens group 63 are all accommodated within the housing 61. The housing 61 is provided with a light inlet 611 and a light outlet 612. The image light L1 emitted from the coupling structure 50 enters the first light guiding element 62 through the light entrance hole 611, and the image light L1 coupled from the coupling structure 50 passes through the first light guiding element 62, the lens group 63, and the second light guiding element 64 in sequence and then is coupled into the optical waveguide 70 through the light exit hole 612, and the image light L1 is totally reflected and propagated in the optical waveguide 70 and is coupled out to human eyes from the coupling structure 80.

In the embodiment shown in fig. 3, the first light directing element 62 and the second light directing element 64 are turning prisms. The first light guiding element 62 is used for guiding the light coupled in from the coupling-in structure 50 to the lens group 63. The second light guiding element 64 serves to guide the light passing through the lens group 63 to the light exit aperture 612 and to enable it to be coupled into the optical waveguide 70 at a specific angle of incidence.

Understandably, in other embodiments, the first and second light directing elements 62, 64 are not limited to turning prisms. For example, the first and second light directing elements 62 and 64, respectively, may also be mirrors. Alternatively, one of the first light guiding element 62 and the second light guiding element 64 is a mirror and the other is a turning prism.

In one embodiment, the optical waveguide 70 has a refractive index of 1.4 to 1.6 (e.g., transparent glass). To improve color shift, the turning prism is a low refractive index material, or a material with a refractive index close to that of the optical waveguide 70. Specifically, the refractive index of the turning prism is 1.4 to 1.6, and the material of the turning prism is, for example, polymethyl methacrylate (PMMA), but is not limited thereto.

In addition, the near-eye display device 100 may further include a turning grating (not shown) on the optical waveguide 70 to implement a transverse pupil expansion and a longitudinal pupil expansion, so as to increase the viewing angle and enhance the user experience.

In the embodiment shown in fig. 3, the number of lenses in the lens group 63 is three, and each lens is a convex lens. Defining the direction from the first light guiding element 62 to the second light guiding element 64, the three lenses are in turn a first lens 631, a second lens 632 and a third lens 633. The position of at least one of the three lenses is adjustable by a user via a knob 65 to change the focal length before the image light L1 enters the optical waveguide 70. Especially for users with different eyesight, the position of the lens with adjustable position in the lens group 63 can be adjusted by the knob 65, so that the requirement of zooming is realized, the wearing comfort is improved, and the viewing experience is enhanced.

In other embodiments, the number of lenses in the lens group 63 is not limited to three, such as one, two, or more than three. The type of lenses in the lens group 63 is not limited to convex lenses, and each lens may also be one of a concave lens and a meniscus lens, for example. In addition, regardless of the number of lenses in the lens group 63 being one or more, the position of at least one lens in the lens group 63 is adjustable to change the focal length of the image light L1.

As shown in fig. 4A and 4B, the number of lenses in the lens group 63 is three, wherein the first lens 631 and the third lens 633 are convex lenses, and the second lens 632 is a concave lens. In the embodiment shown in fig. 4A and 4B, the second lens 632 is a position adjustable lens. As shown in fig. 4A and 4B, the first lens 631 and the third lens 633 are stationary, i.e., the distance D between the first lens 631 and the third lens 633 is a fixed value. The second lens 632 can translate back and forth between the first lens 631 and the third lens 633 along the optical axis X to change the convergence degree of the image light L1, so as to change the distance from a virtual image formed by the image light L1 after passing through the optical waveguide 70 to the human eyes, thereby improving the wearing comfort. Especially to the user of eyesight difference, the user can be according to the definition of virtual image before the eye, adjusts the focus of image light L1 through focusing subassembly 60, does benefit to promote to watch and experiences. In addition, the focusing assembly 60 can adjust the focal length, and can also enlarge or reduce the real image.

In one embodiment, the focusing assembly 60 further comprises a position adjustment structure (not shown). The position adjusting structure is connected with the position-adjustable lens and is used for driving the position-adjustable lens to move. The position adjustment structure includes, for example, a motor (not shown) connected to the position-adjustable lens, and the motor is used for driving the position-adjustable lens to translate.

Specifically, the position adjustment structure further includes a transmission mechanism (not shown) and a control unit (not shown). The motor is connected with the position-adjustable lens through a transmission mechanism. The control unit comprises a signal input (not shown) and a signal input (not shown). The knob 65 is connected to the signal input of the control unit. The motor is connected with the signal output end of the control unit. The user may provide a control signal to the control unit via the knob 65, and the control unit may output a signal to the motor to drive the motor to rotate. The motor drives the transmission mechanism to enable the zoom lens to move horizontally, and then the zoom function is achieved.

The transmission mechanism includes, for example, a driving gear (not shown) connected to the motor, a driven gear (not shown) engaged with the driving gear, a threaded sleeve (not shown) coinciding with an axis of the driven gear, and a screw (not shown) threadedly engaged with the threaded sleeve. The motor rotates to drive the driving gear to rotate, the driven gear rotates along with the rotation of the driving gear, the threaded sleeve rotates along with the driven gear, and the screw and the threaded sleeve are driven by the threaded fit to enable the lens with the adjustable position in the lens group 63 connected with the screw to move along the direction of the optical axis X, so that the purpose of adjusting the focal length of the near-to-eye display device 100 is achieved. In other embodiments, the position adjusting structure is not limited to focusing by matching of the gear pair and the screw pair, as long as the position adjusting structure can move the lens.

In one embodiment, the number of lenses in the lens group 63 is one, and the lenses are meta lenses (also called meta lenses). However, when the lens is a superlens, the image light L1 passing through the lens group 63 can be prevented from being dispersed. And in the case that the lens is a superlens, the lens with adjustable position in the lens group 63 is a superlens.

Specifically, the superlens is flat (planar) and is ultra-thin, so that chromatic aberration is not generated by the superlens. A superlens is an "achromatic" lens in that light of all wavelengths passes through almost simultaneously. Advantages of superlenses also include tunable dispersion (the ability to control how light color is dispersed), unlike glass or other conventional materials that have fixed dispersion. Moreover, the superlens does not need to have the same curvature as that of the refractive lens, so that the superlens is easier to process and can even be directly grown on the carrier by directly utilizing the semiconductor processing technology.

FIG. 5 is a schematic diagram of an imaging principle of a superlens in another embodiment of the present application. As shown in fig. 5, the superlens 634 includes a support 6341 and a plurality of micro-nano structures 6342 disposed on the support 6341. The micro-nano structure 6342 is a nanorod. By adjusting the length, width, height, rotation angle, distribution rule on the carrier 6341, and the like of the micro-nano structure 6342, the characteristics of the light incident on the superlens 634, such as amplitude, phase, polarization, and the like, can be adjusted, so that the light incident on the superlens 634 (for example, the image light L1 including red light, green light, and blue light) is focused at a specific position.

Specifically, according to the light path requirements, the focusing positions of light with different wavelengths can be calculated through simulation of optical software, so that the length, the width, the height, the rotation angle, the distribution rule on the carrier 6341 and the like of the micro-nano structure 6342 are modified, the required structural parameters of the superlens are obtained, and the three primary color lights (i.e., red light, green light and blue light) are focused on the same point. And then, by utilizing a semiconductor manufacturing process, for example, a film is coated to etch a required pattern, so that a plurality of micro-nano structures 6342 grow on the carrier 6341, and the required super lens is obtained. In an embodiment, the micro-nano structure 6342 is a titanium dioxide nanorod with a height of approximately 600 nm, but is not limited thereto. The material of carrier 6341 is transparent glass, transparent plastic or other low refractive index material.

To sum up, the near-to-eye display device of this application embodiment because the focus of the image light that adjusting part can change the image source outgoing for the user can adjust the virtual image that the image source formed to the distance of people's eye according to the demand, make the virtual image that people's eye sees be the distance variable and the non-state of focusing that is in always, make the ciliary muscle of people's eye can move thereupon, thereby alleviate the tired sense of people's eye, avoid dizzy production, reach the purpose of relaxing.

In addition, because foretell near-to-eye display device can change the focus of image light through the focusing subassembly, can directly wear near-to-eye display device to the user of vision difference, and need not to wear myopia glasses earlier and wear near-to-eye display device again, has solved the inconvenient problem of myopia person's dress, has promoted the comfort level of wearing.

Moreover, in the embodiment of the application, the focusing assembly of the near-eye display device is located at the frame to realize focusing of the virtual image, and the observation of the real world (real image) in front of the eyes cannot be shielded during use.

Although the present application has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the present application.

Claims (10)

1. A near-eye display device, comprising:

an image source for emitting image light;

a focusing assembly for changing a focal length of the image light;

a coupling structure located between the image source and the focusing assembly for optically coupling the image into the focusing assembly;

the optical waveguide is positioned on the light emergent side of the focusing component; and

the coupling-out structure is positioned in the light emitting area of the optical waveguide;

wherein the image light propagates in the optical waveguide after passing through the focusing assembly and is coupled out of the optical waveguide from the coupling-out structure.

2. The near-eye display device of claim 1, wherein the focusing assembly comprises:

a first light directing element;

a second light directing element spaced from the first light directing element; and

a lens group between the first light guiding element and the second light guiding element;

the lens group comprises at least one lens with adjustable position, and the image light emitted from the coupling-in structure is coupled into the optical waveguide after sequentially passing through the first light guide element, the lens group and the second light guide element.

3. The near-eye display device of claim 2, wherein the number of lenses in the lens group is plural, each of the lenses being one of a convex lens, a concave lens, and a meniscus lens.

4. The near-eye display device of claim 2, wherein the number of lenses in the lens group is one, the lenses being superlenses.

5. The near-eye display device of claim 2, wherein the first light directing element is one of a mirror and a turning prism, and the second light directing element is one of a mirror and a turning prism.

6. The near-eye display device of claim 5, wherein the first light directing element and the second light directing element are turning prisms, the refractive index of the optical waveguide is 1.4 to 1.6, and the refractive index of the turning prisms is 1.4 to 1.6.

7. The near-eye display device of claim 2, wherein the focusing assembly further comprises a housing, the first light directing element, the second light directing element, and the lens group all being housed within the housing;

the shell is provided with a light inlet and a light outlet, the image light emitted from the coupling-in structure enters the first light guide element through the light inlet, and the image light emitted from the second light guide element enters the optical waveguide after passing through the light outlet.

8. The near-eye display device of any one of claims 2-7, wherein the focusing assembly further comprises a position adjustment structure coupled to the position adjustable lens, the position adjustment structure configured to move the position adjustable lens.

9. The near-eye display device of claim 8, wherein the position adjustment structure comprises a motor coupled to the position-adjustable lens, the motor configured to translate the position-adjustable lens.

10. The near-eye display device of claim 9, wherein the focusing assembly further comprises a transmission mechanism, a knob, and a control unit;

the motor is connected with the position-adjustable lens through the transmission mechanism;

the knob is connected with the signal input end of the control unit;

the motor is connected with the signal output end of the control unit.

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