Display lens and near-to-eye display device

Abstract

The utility model discloses a display lens and a near-to-eye display device. The display lens comprises at least one optical waveguide sheet and at least one protection sheet which are arranged in a stacked mode, a grating structure is arranged on the optical waveguide sheet, and the optical waveguide sheet and the protection sheet are connected through a filling adhesive layer. A nesting structure is arranged on the surface, connected with the filling adhesive layer, of the protection sheet, the nesting structure is laid on the whole surface of the protection sheet, or a tackifying layer is arranged between the protection sheet and the filling adhesive layer, a nesting structure is arranged on the surface, connected with the filling adhesive layer, of the tackifying layer, and the nesting structure is laid on the whole surface of the tackifying layer; the connection between the optical waveguide sheet and the protection sheet is reinforced through nesting and clamping of the nesting structure; the refractive index of the filling adhesive layer and the refractive index of the tackifying layer are smaller than the refractive index of the grating structure and smaller than the refractive index of the optical waveguide sheet. According to the display lens provided by the utility model, the problems that the optical waveguide sheet and the protection sheet are not firmly bonded and gaps exist can be solved on the premise of not influencing the lighting effect, and the performance and the stability of the optical lens are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to near-to-eye display technical field especially relates to a display lens and near-to-eye display device. BACKGROUND

[0002] In recent years, optical waveguide has advantages in volume, light transmittance, definition, field of view and the like, and is expected to become a mainstream augmented reality (AR) optical scheme, and is paid attention to by the AR smart glasses market. The diffractive optical waveguide has advantages of large eye movement range, small volume and good mass productivity, and is favored by many enterprises.

[0003] The diffractive optical waveguide usually comprises at least one optical waveguide sheet and at least one protective sheet, the optical waveguide sheet is provided with a grating structure, and the optical waveguide sheet and the protective sheet or the optical waveguide sheet and the waveguide sheet are usually connected in a laminated mode through frame bonding or filling adhesive, but the frame bonding and the ordinary filling adhesive have the problem of poor adhesion. UTILITY MODEL CONTENT

[0004] The utility model provides a kind of display lens and near-to-eye display device, the display lens can solve the problem of poor adhesion and gap between optical waveguide sheet and protective sheet under the premise of not affecting light effect, improve the performance and stability of optical lens.

[0005] According to an aspect of the utility model, a kind of display lens is provided, including at least one optical waveguide sheet and at least one protective sheet in laminated mode, the optical waveguide sheet is provided with grating structure, and the optical waveguide sheet and the protective sheet are connected by filling adhesive between the protective sheet;

[0006] The surface of the protective sheet connected with the filling adhesive layer is provided with a nested structure, the nested structure covers the entire surface of the protective sheet, or an adhesion-increasing layer is provided between the protective sheet and the filling adhesive layer, the surface of the adhesion-increasing layer connected with the filling adhesive layer is provided with a nested structure, and the nested structure covers the entire surface of the adhesion-increasing layer.

[0007] The filling adhesive layer fills the nested structure, and the connection between the optical waveguide sheet and the protective sheet is reinforced by the nested clamping of the nested structure.

[0008] The refractive index of the filling adhesive layer and the refractive index of the adhesion-increasing layer are less than the refractive index of the grating structure and the refractive index of the optical waveguide sheet.

[0009] Optionally, the protective sheet includes a first protective sheet and a second protective sheet, the optical waveguide sheet is located between the first protective sheet and the second protective sheet, the first protective sheet is located on the side of the optical waveguide sheet provided with the grating structure, and the nested structure is located between the first protective sheet and the grating structure.

[0010] Optionally, the surface of the second protective sheet close to the optical waveguide sheet is a plane, and the second protective sheet is connected to the optical waveguide sheet directly through the filling adhesive layer.

[0011] Optionally, the optical waveguide sheet and the second protective sheet are connected through the filling adhesive layer.

[0012] The surface of the second protective sheet connected to the filling adhesive layer is provided with a nested structure, and the nested structure covers the entire surface of the second protective sheet, or an adhesion-increasing layer is arranged between the second protective sheet and the filling adhesive layer, and the surface of the adhesion-increasing layer connected to the filling adhesive layer is provided with a nested structure, and the nested structure covers the entire surface of the adhesion-increasing layer.

[0013] Optionally, the nested structure between the first protective sheet and the optical waveguide sheet is the same as the nested structure between the second protective sheet and the optical waveguide sheet.

[0014] Optionally, the nested structure has at least one of a rectangular shape, an oblique parallelogram shape, an inverted T shape, a trapezoidal shape, an inverted trapezoidal shape, or a bent shape in a first cross-sectional shape, and the first cross-sectional shape is perpendicular to the plane in which the optical waveguide sheet is located.

[0015] Optionally, the nested structure is provided in a first grating of a first period.

[0016] Optionally, the first period satisfies:

[0017]

[0018] wherein P is the first period, λ is the wavelength of light incident into the display lens, and n is the refractive index of the optical waveguide sheet.

[0019] Optionally, the height of the first grating ranges from 20 nm to 200 nm, and the duty cycle ranges from 10% to 90%.

[0020] Optionally, the height of the first grating ranges from 60 nm to 160 nm, and the duty cycle ranges from 30% to 70%.

[0021] Optionally, the refractive index of the filling adhesive layer ranges from 1.1 to 1.5, and the refractive index of the optical waveguide sheet ranges from 1.5 to 2.0.

[0022] Optionally, a lens structure is further arranged on at least one side of the display lens, the lens structure has a positive or negative optical power, and the lens structure is provided with a nested structure close to one side of the display lens.

[0023] Optionally, the protective sheet is multiplexed as the lens structure.

[0024] Optionally, the lens structure is a variable focus lens structure.

[0025] According to another aspect of the present application, a near-eye display device is provided, comprising an optical engine and the display lens described above.

[0026] The display lens provided in the embodiments of the present application comprises at least one light waveguide sheet and at least one protective sheet which are arranged in a stack, the light waveguide sheet is provided with a grating structure, and the light waveguide sheet and the protective sheet are connected through a filling adhesive layer. The nesting structure is arranged on the surface of the protective sheet connected with the filling adhesive layer, the nesting structure covers the surface of the entire protective sheet, or an adhesion-increasing layer is arranged between the protective sheet and the filling adhesive layer, the nesting structure is arranged on the surface of the adhesion-increasing layer connected with the filling adhesive layer, and the nesting structure covers the surface of the entire adhesion-increasing layer, so that the nesting structure is connected through nesting clamping to reinforce the connection between the light waveguide sheet and the protective sheet. The refractive index of the filling adhesive layer and the refractive index of the adhesion-increasing layer are less than the refractive index of the grating structure and less than the refractive index of the light waveguide sheet, so as to ensure the transmittance of the display lens. The display lens provided in the embodiments of the present application is connected through the nesting clamping of the nesting structure to reinforce the connection between the protective sheet and the light waveguide sheet, improve the bonding force during full lamination, prevent the two from being separated, and improve the stability of the lens in use.

[0027] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0029] Figure 1 A structural schematic diagram of a display lens provided in the embodiments of the present application is shown in the figure;

[0030] Figure 2 A structural schematic diagram of another display lens provided in the embodiments of the present application is shown in the figure;

[0031] Figures 3-7 A structural schematic diagram of another display lens provided in the embodiments of the present application is shown in the figure;

[0032] Figure 8 A structural schematic diagram of another display lens provided in the embodiments of the present application is shown in the figure;

[0033] Figure 9 Another structure diagram of a display lens is provided for the embodiments of the present application.

[0034] Figures 10-11 Another structure diagram of a display lens is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0035] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the present application.

[0036] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0037] In order to solve the problem of poor adhesion of the existing display lens frame and ordinary filling glue layer, the embodiments of the present application provide a display lens, which comprises at least one light waveguide sheet and at least one protective sheet arranged in layers, a grating structure is arranged on the light waveguide sheet, and the light waveguide sheet and the protective sheet are connected through a filling glue layer; a nesting structure is arranged on the surface of the protective sheet connected with the filling glue layer, the nesting structure covers the entire surface of the protective sheet, or an adhesion increasing layer is arranged between the protective sheet and the filling glue layer, a nesting structure is arranged on the surface of the adhesion increasing layer connected with the filling glue layer, and the nesting structure covers the entire surface of the adhesion increasing layer; the filling glue layer fills the nesting structure, and the connection between the light waveguide sheet and the protective sheet is reinforced through the nesting clamping of the nesting structure; wherein the refractive index of the filling glue layer and the refractive index of the adhesion increasing layer are less than the refractive index of the grating structure and the refractive index of the light waveguide sheet.

[0038] The technical scheme of the embodiments of the present application reinforces the connection between the protective sheet and the light waveguide sheet through the nesting clamping action of the nesting structure, improves the bonding force during overall lamination, prevents separation of the two, and improves the stability of the lens in use.

[0039] The above is the core idea of the embodiment of the present application, and some specific embodiments of the present application will be described below with reference to the drawings. Exemplarily, a one-layer optical waveguide sheet and a one-layer protective sheet are taken as examples, Figure 1 A structure diagram of a display lens provided by the embodiment of the present application is shown in FIG. 1, Figure 2 A structure diagram of another display lens provided by the embodiment of the present application is shown in FIG. 2, which is described with reference to Figure 1 and Figure 2 The display lens comprises an optical waveguide sheet 10 and a protective sheet 20 arranged in a stack, and the optical waveguide sheet 10 is provided with a grating structure, wherein the grating structure comprises a coupling-in grating 11 and a coupling-out grating 12. In other embodiments, the grating structure can also be provided with a turning grating, wherein Figure 1 and Figure 2 The specific structure of each grating is not shown. With reference to Figure 1 The optical waveguide sheet 10 and the protective sheet 20 are connected through a filling adhesive layer 30; the surface of the protective sheet 10 connected with the filling adhesive layer 30 is provided with a nesting structure 21, the nesting structure 21 covers the entire surface of the protective sheet 20, the filling adhesive layer 30 fills the nesting structure 21, and the connection between the optical waveguide sheet 10 and the protective sheet 20 is reinforced through the nesting clamping of the nesting structure. With reference to Figure 2 The protective sheet 20 and the filling adhesive layer 30 are provided with an adhesion-increasing layer 40, the surface of the adhesion-increasing layer 40 connected with the filling adhesive layer 30 is provided with a nesting structure 41, and the nesting structure 41 covers the entire surface of the adhesion-increasing layer 40; the filling adhesive layer 30 fills the nesting structure 41, and the connection between the optical waveguide sheet 10 and the protective sheet 20 is reinforced through the nesting clamping of the nesting structure 41; wherein the refractive index of the filling adhesive layer 30 and the refractive index of the adhesion-increasing layer 40 are less than the refractive index of the grating structure and less than the refractive index of the optical waveguide sheet 10.

[0040] By arranging the nesting structure between the optical waveguide sheet 10 and the protective sheet 20, the contact area of the connection interface can be increased, thereby increasing the bonding force. In specific implementation, the nesting structure can be arranged periodically or non-periodically, or the nesting structure can comprise multiple shapes, which can be arranged according to actual conditions in specific implementation.

[0041] Optionally, the cross-sectional shape of the nesting structure in the first section comprises at least one of a rectangle, an oblique parallelogram, an inverted T shape, a trapezoid, an inverted trapezoid or a bent shape, and the first section is perpendicular to the plane in which the optical waveguide sheet is located.

[0042] Exemplarily, Figures 3-7 Another structure diagram of a display lens provided by the embodiment of the present application is shown in FIG. 3, which takes the nesting structure arranged on the surface of the protective sheet as an example, Figure 1 The cross-sectional shape of the nesting structure 21 in the first section (YZ plane) shown in FIG. 3 is a rectangle (i.e. a straight-tooth shape),Figure 3 In the first cross section, the cross-sectional shape of the nested structure 21 is shown as a trapezoidal shape, Figure 4 In the first cross section, the cross-sectional shape of the nested structure 21 is shown as an inverted T shape, Figure 5 In the first cross section, the cross-sectional shape of the nested structure 21 is shown as a trapezoidal shape, Figure 6 In the first cross section, the cross-sectional shape of the nested structure 21 is shown as an inverted trapezoidal shape, Figure 7 In the first cross section, the cross-sectional shape of the nested structure 21 is shown as a trapezoidal shape,

[0043] It can be understood that the nested structure 21 can be extended as a strip along the X direction, or the nested structure 21 can be designed as a column, which can be designed according to actual conditions during implementation. It should be noted that the dashed line in the figure is used to show the shape of the nested structure, and is not the actual structure.

[0044] In another embodiment, Figure 8 Another structure diagram of a display lens provided by the embodiment of the present application is shown in FIG. 9. Figure 8 Optionally, the protective sheet 20 includes a first protective sheet 210 and a second protective sheet 220, the optical waveguide sheet 10 is located between the first protective sheet 210 and the second protective sheet 220, the first protective sheet 210 is located on the side of the optical waveguide sheet 10 provided with the grating structure, and the nested structure 21 is located between the first protective sheet 210 and the grating structure.

[0045] It can be understood that in some embodiments, the optical waveguide sheet can be made of a fragile material such as glass material, in order to better protect the optical waveguide sheet, the protective sheet can be arranged on both sides of the optical waveguide sheet, thereby improving the service life of the display lens. Optionally, referring back to Figure 8 The surface of the second protective sheet 220 close to the side of the optical waveguide sheet 10 is a plane, and the second protective sheet 220 is connected with the optical waveguide sheet 10 through the filling adhesive layer 30.

[0046] In another embodiment, the nested structure can also be arranged on the protective sheets on both sides of the optical waveguide sheet, for example, Figure 9 Another structure diagram of a display lens provided by the embodiment of the present application is shown in FIG. 9. Figure 9 Optionally, the optical waveguide sheet 10 and the second protective sheet 220 are connected through the filling adhesive layer 30; the surface of the second protective sheet 220 connected with the filling adhesive layer 30 is provided with the nested structure 21, and the nested structure 21 covers the entire surface of the second protective sheet 220.

[0047] It can be understood that, Figure 9The shown embodiment shows that the nesting structure 21 is arranged on the surface of the second protective sheet 220, and in another embodiment, the nesting structure can also be arranged on the surface of the first protective sheet 210. Figure 2 The shown embodiment shows that the nesting structure is arranged on the surface of the second protective sheet and the filling glue layer, and the nesting structure is arranged on the surface of the filling glue layer connected with the adhesion layer.

[0048] Optionally, continuing to refer to Figure 9 The nesting structure between the first protective sheet 210 and the optical waveguide sheet 10 is the same as the nesting structure between the second protective sheet 220 and the optical waveguide sheet 10. Such arrangement is beneficial to simplify the process and reduce the manufacturing cost of the display lens. In other embodiments, the shapes of the two nesting structures can be different, and the shape of the nesting structure can refer to the foregoing embodiments, which will not be described in detail here.

[0049] The embodiment of the utility model discloses the nesting structure's nesting clamping reinforcement between the connection of optical waveguide sheet and protective sheet, and still have a problem is how to increase the bonding force when pasting, improve the optical transmittance of display lens. In order to not affect the display effect, the nesting structure can be designed as a periodic structure, and the period of the nesting structure is small enough. Optionally, the nesting structure is arranged as a first grating of a first period.

[0050] The first grating can be arranged as a one-dimensional grating or a two-dimensional grating, which can be selected according to actual conditions during implementation. Optionally, the first period satisfies:

[0051]

[0052] Wherein P is the first period, λ is the wavelength of the light incident into the display lens, and n is the refractive index of the optical waveguide sheet.

[0053] To avoid affecting the display effect, the period of the nested structure is set to be less than twice the wavelength divided by the refractive index of the waveguide sheet, where the wavelength of light is the minimum wavelength of light transmitted within the display lens. For example, when the refractive index of the waveguide sheet substrate is typically set to approximately 1.5–2.0, since the minimum wavelength of green light is 500nm, the nested structure period for a single green light engine module should be less than 125nm according to the above formula to ensure that the display effect of green light is not affected. Similarly, since the minimum wavelength of visible light is 400nm, the nested structure period for a full-color light engine module should be less than 100nm. Furthermore, to improve the optical transmittance of the display lens, the refractive index of the filler layer can optionally be in the range of 1.1–1.5, and the refractive index of the waveguide sheet can optionally be in the range of 1.5–2.0. The nested structure can be a straight tooth or a helical tooth structure; optionally, the height of the first grating can range from 20nm to 200nm, and the duty cycle can range from 10% to 90%. Preferably, the height of the first grating is in the range of 60nm to 160nm, and the duty cycle is in the range of 30% to 70%, resulting in a more significant anti-reflection effect, which can increase the transmittance from 98.76% to 99.87%. Similarly, grating shapes such as inverted T-shape, trapezoidal shape, inverted trapezoidal shape, bent shape, and oblique tooth shape, within the above preferred parameter range, can all help increase the optical transmittance of the display lens.

[0054] The technical solution of this utility model embodiment strengthens the connection between the protective sheet and the optical waveguide sheet through the nested snap-fit ​​effect of the nested structure, improves the bonding force when fully bonded, prevents the two from separating, and improves the stability of the lens in use; at the same time, the nested structure through which light passes can increase the optical transmittance of the display lens within the preferred parameter range.

[0055] In another embodiment, a concave or convex lens may be provided on at least one side of the display lens to accommodate the needs of users with refractive errors. Figures 10-11 These are schematic diagrams of another display lens provided in the embodiments of this utility model, for reference. Figure 10 or Figure 11 Optionally, the display lens also includes a lens structure 50 disposed on at least one side of the display lens, the lens structure 50 having positive optical power ( Figure 10 or negative power ( Figure 11 The lens structure 50 has a nested structure on the side near the display lens.

[0056] Optional, continue to refer to Figure 10 or Figure 11 The protective sheet 20 is reused as a lens structure 50. That is, the shape of the protective sheet 20 is directly designed as the lens structure 50. In other embodiments, the lens structure 50 can also be formed by adding a film layer, and a nested structure can be set on one side of the lens structure 50.

[0057] In another embodiment, the lens structure is a variable focus lens structure.

[0058] In recent years, with the progress of the technology related to near-eye display systems, the technology related to variable focus lens elements has also emerged, which provides appropriate optical power by adding variable focus lens elements between the waveguide and the environment or between multiple waveguides, helping to adjust the refractive error of the eye and place the displayed virtual content on the required depth plane. The present solution can also be applied to similar technologies to help more firmly arrange the variable focus lens elements therein and not affect its display effect.

[0059] Furthermore, the technology related to adding related elements on the near-eye display system can also use the pasting method of the present solution to obtain a more firm pasting effect.

[0060] Based on the same idea, the embodiments of the present application also provide a near-eye display device, which comprises an optical machine and any one of the display lenses provided in the above embodiments.

[0061] The optical machine is used to output image light, and the image light is transmitted from the coupling-in grating to the display lens and then coupled out from the coupling-out grating to the human eye.

[0062] The above specific embodiments do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A display lens, characterized by, The display lens comprises at least one light waveguide sheet and at least one protective sheet which are arranged in a stack, the light waveguide sheet is provided with a grating structure, and the light waveguide sheet and the protective sheet are connected through a filling adhesive layer; The surface of the protective sheet connected with the filling adhesive layer is provided with a nested structure which covers the entire surface of the protective sheet, or an adhesion-increasing layer is arranged between the protective sheet and the filling adhesive layer, the surface of the adhesion-increasing layer connected with the filling adhesive layer is provided with a nested structure which covers the entire surface of the adhesion-increasing layer; The filling adhesive layer fills the nested structure, and the connection between the light waveguide sheet and the protective sheet is reinforced through the nested engagement of the nested structure. The refractive index of the filling adhesive layer and the refractive index of the adhesion-increasing layer are less than the refractive index of the grating structure and the refractive index of the light waveguide sheet.

2. The display lens of claim 1, wherein, The protective sheet comprises a first protective sheet and a second protective sheet, the light waveguide sheet is located between the first protective sheet and the second protective sheet, the first protective sheet is located on the side of the light waveguide sheet provided with the grating structure, and the nested structure is located between the first protective sheet and the grating structure.

3. The display lens of claim 2, wherein, The surface of the second protective sheet close to the side of the light waveguide sheet is a plane, and the second protective sheet is directly connected with the light waveguide sheet through a filling adhesive layer.

4. The display lens of claim 2, wherein, The light waveguide sheet and the second protective sheet are connected through a filling adhesive layer. The surface of the second protective sheet connected with the filling adhesive layer is provided with a nested structure which covers the entire surface of the second protective sheet, or an adhesion-increasing layer is arranged between the second protective sheet and the filling adhesive layer, the surface of the adhesion-increasing layer connected with the filling adhesive layer is provided with a nested structure which covers the entire surface of the adhesion-increasing layer.

5. The display lens of claim 4, wherein, The nested structure between the first protective sheet and the light waveguide sheet is the same as the nested structure between the second protective sheet and the light waveguide sheet.

6. The display lens of claim 1 or 4, wherein, The cross-sectional shape of the nested structure in a first section includes at least one of a rectangle, an oblique parallelogram, an inverted T shape, a trapezoid, an inverted trapezoid, or a bent shape, and the first section is perpendicular to the plane in which the light waveguide sheet is located.

7. The display lens of claim 1 or 4, wherein, The nested structure is provided in a first grating with a first period.

8. The display lens of claim 7, wherein, The first period satisfies: wherein P is the first period, λ is the wavelength of light incident into the display lens, and n is the refractive index of the light waveguide sheet.

9. The display lens of claim 7, wherein, The height of the first grating ranges from 20 nm to 200 nm, and the duty cycle ranges from 10% to 90%.

10. The display lens of claim 9, wherein, The height of the first grating ranges from 60 nm to 160 nm, and the duty cycle ranges from 30% to 70%.

11. The display lens of claim 1, wherein, The refractive index of the filling adhesive layer ranges from 1.1 to 1.5, and the refractive index of the light waveguide sheet ranges from 1.5 to 2.

0.

12. The display lens of claim 1, wherein, A lens structure is further arranged on at least one side of the display lens, the lens structure has a positive or negative focal power, and the lens structure is provided with a nested structure on the side close to the display lens.

13. The display lens of claim 12, wherein, The protective sheet is multiplexed as the lens structure.

14. The display lens of claim 12, wherein, The lens structure is a variable-focus lens structure.

15. A near-eye display device, comprising: The display lens is combined with an optical machine.

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