Display device

[0037] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described The embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0038] Please refer to figure 1 , figure 1 It is a schematic diagram of the optical path of an existing waveguide-based display device. It is assumed that the diffraction efficiency of the coupling element 11 is 30%. Without considering the absorption, the energy of the incident light 1 is 100%, and the light 2 is the 0th order output of the incident light 1. Light, energy is 70%, light 3 is diffracted light of incident light 1, energy is 30%; light 4 is diffracted light of light 3, energy is 9%; light 5 is coupled into waveguide layer 10 by coupling element 11 The energy of 21% is 21%, that is, 21% of the energy enters the waveguide layer 10 for transmission. The coupling efficiency of the waveguide-based display device is 21%.

[0039] An embodiment of the present invention provides a display device, including an image projection device and first to Nth waveguide layers. The first to Nth waveguide layers are arranged in order from near to far away from the projection device, and N is greater than or equal to 2. The projection device is used to project image light.

[0040] A first preset area of ​​each waveguide layer is provided with a coupling portion for coupling image light into the waveguide layer, and a second preset area of ​​each waveguide layer is provided with a coupling portion for coupling the waveguide The image light propagating in the layer is coupled out of the coupling out part outside the waveguide layer;

[0041] The coupling portion of the first waveguide layer is specifically used to couple the image light projected by the imaging device into the first waveguide layer, and the coupling portion of the i-th waveguide layer is specifically used to couple the uncoupled front The image light of a waveguide layer and transmitted from the first predetermined area of ​​the previous waveguide layer is coupled into the i-th waveguide layer, iε[2, N].

[0042] The waveguide layer is a waveguide structure capable of guiding light propagation. The first to Nth waveguide layers are arranged in order from near to far away from the imaging device, the first preset area of ​​each waveguide layer is located at the same end of each waveguide layer, and the second preset area of ​​each waveguide layer is located at each waveguide layer Corresponding position.

[0043] The projection device projects image light to the waveguide layer, the coupling part of the first waveguide layer couples the image light projected by the projection device into the first waveguide layer, and the coupling part of the i-th waveguide layer will not couple into the previous waveguide layer The image light transmitted from the first predetermined area of ​​the previous waveguide layer is coupled into the i-th waveguide layer. The coupling-out part provided in the second preset area of ​​the waveguide layer couples the image light propagating in the waveguide layer out of the waveguide layer, and the image light coupled from each waveguide layer enters the eyes of the user to realize display.

[0044] In the display device of this embodiment, by providing multiple waveguide layers, image light that is not coupled into the waveguide layer by the previous waveguide layer can be coupled again by the latter waveguide layer, for example figure 1 In the display device shown, the 0th-order outgoing light 2 transmitted out of the waveguide layer and the light coupled into the waveguide layer are diffracted by the coupling element again to couple out the light 4 outside the waveguide layer. The display device of this embodiment can pass this through the rear waveguide layer. Part of the light is coupled again, so it can be seen that compared with the prior art, the display device can reduce light leakage, improve the utilization rate of light energy, and improve the performance and user experience of the display device.

[0045] Hereinafter, the display device will be described in detail with reference to specific embodiments and drawings. Please refer to figure 2 , figure 2 It is a schematic diagram of the display device of the first embodiment. It can be seen from the figure that the display device includes an imaging device 20 and the first to Nth waveguide layers 21, and N is a positive integer greater than or equal to 2.

[0046] The image projection device 20 is used to project image light. The image projection device may be a light projection machine, or various types of light projection machines, all of which fall within the protection scope of the present invention.

[0047] The first to Nth waveguide layers 21 are arranged in order from near to far away from the imaging device 20, and the first preset area of ​​each waveguide layer 21 is provided with a coupling portion for coupling image light into the waveguide layer 21, Please refer to figure 2 The coupling part may specifically include an optical element 210 disposed on the side of the first predetermined area of ​​the waveguide layer 21 far away from the imaging device 20, and the optical element 210 is used to couple image light into the waveguide layer 21, from the imaging device 20 or the front The image light propagated by a waveguide layer 21 is diffracted by the optical element 210 of the current waveguide layer, and the generated diffracted light is coupled into the current waveguide layer 21 and propagates in the form of total reflection. Among them, the coupling portion of the first waveguide layer is used to couple the image light projected by the imaging device 20 into the first waveguide layer, and the coupling portion of the i-th waveguide layer is used to couple the light from the previous waveguide layer that is not coupled into the previous waveguide layer. The image light transmitted from the first predetermined area of ​​the waveguide layer is coupled into the i-th waveguide layer, iε[2, N].

[0048] Please refer to image 3 , image 3 The optical path schematic diagram of the display device of this embodiment includes two waveguide layers, where the display device includes two waveguide layers, namely, the first waveguide layer 31 and the second waveguide layer 32 as an example. As shown in the figure, a coupling portion 310 is provided on the side of the first predetermined area of ​​the first waveguide layer 31, and a coupling portion 320 is provided on the side of the first predetermined area of ​​the second waveguide layer 32. The optical element of each coupling portion The diffraction efficiency is 30%. Light 1 is the incident image light, the energy is 100%, light 2 is the 0-order emitted light of light 1, the energy is 70%; light 3 is the diffracted light of light 1, the energy is 30%; light 4 is the diffracted light of light 3, The energy is 9%; the light 5 is the 0-level light of the light 3 at the coupling part 310, and the energy is 21%. The light 6 is the diffracted light of the light 2 at the coupling part 320 of the second waveguide layer 32, and the energy is 21%; the light 7 is the 0-order light of the light 2 at the coupling 320, and the energy is 49%; the light 8 is the light 6 at the coupling The energy of the diffracted light of the entrance 320 is 6.3%; the light 9 is the 0-order light of the light 6 at the coupling 320, and the energy is 14.7%; the light 10 is the diffracted light of the light 4 at the coupling 320, and the energy is 2.7%; It is the 0-level light of light 4 at the coupling part 320, and the energy is 6.3%. It can be seen that the combined coupling efficiency of the first waveguide layer 31 and the second waveguide layer 32 is 38.4%, that is, 38.4% of the energy of the light is coupled into the waveguide layer for transmission. It can be seen that with figure 1 Compared with the display device shown, the waveguide efficiency of the display device of this embodiment is improved by 83%, which greatly improves the light energy utilization rate.

[0049] in figure 2 with image 3 In the display device shown, the optical element included in the coupling portion is disposed on the side of the first preset area of ​​the waveguide layer 21 away from the imaging device 20 as an example. Optionally, in the display device, the coupling portion may also include The optical element for coupling the image light into the waveguide layer is arranged on the side of the first preset area of ​​the waveguide layer close to the imaging device, which also falls within the protection scope of the present invention.

[0050] In this embodiment, the coupling portion of each waveguide layer may adopt a reflective optical element based on the principle of diffraction, or the coupling portion of each waveguide layer may adopt a transmissive optical element based on the principle of diffraction. Alternatively, the coupling portions of several waveguide layers in the first to Nth waveguide layers are reflective optical elements based on the principle of diffraction, and coupling portions of other waveguide layers are transmissive optical elements based on the principle of diffraction, which are all within the protection scope of the present invention. The optical element of the coupling part may be a grating, and the grating structure of the coupling part grating of each waveguide layer may be the same or different.

[0051] Please refer to figure 2 The second preset area of ​​each waveguide layer is provided with an out-coupling portion 211 for coupling the image light propagating in the waveguide layer 21 out of the waveguide layer. The image light coupled into the waveguide layer 21 is fully distributed in the waveguide layer. The image light propagates in the form of reflection, and the image light propagates in the form of total reflection in the turning area of ​​the waveguide layer. When it travels to the second preset area, it is coupled out by the coupling part 211, and the image light coupled out of each waveguide layer 21 enters the user's eyes. display. The coupling-out portion 211 may be an optical element based on the principle of diffraction. In this embodiment, specifically, the coupling-out portion 211 is provided on the second preset area of ​​each waveguide layer 21 far away from the user's viewing side.

[0052] Preferably, the projections of the second preset regions of the respective waveguide layers 21 along the arrangement direction of the waveguide layers 21 do not overlap with each other, or the projections of the second preset regions of the respective waveguide layers 21 along the arrangement direction of the waveguide layers partially overlap. It is to prevent the second preset areas of each waveguide layer from completely overlapping. If the second preset areas of two waveguide layers completely overlap, the light coupled out of the latter waveguide layer will be incident on the second preset area of ​​the previous waveguide layer. It is coupled out of the optical element and re-coupled into the waveguide layer, so that the light is coupled out as much as possible through the above arrangement, and the light is coupled out as much as possible and enters the user's eyes, which improves the efficiency of the waveguide and improves the light energy utilization.

[0053] Please refer to Figure 4 , Figure 4 It is a schematic diagram of the display device of the second embodiment. It can be seen from the figure that the display device includes an image projection device 40 and first to Nth waveguide layers 41, and N is a positive integer greater than or equal to 2. The image projection device 40 is used to project image light. The image projection device may be a light projection machine, or various types of light projection machines, all of which fall within the protection scope of the present invention.

[0054] The first to Nth waveguide layers 41 are arranged in sequence from near to far according to the distance from the imaging device 40, and the first predetermined area of ​​each waveguide layer 41 is provided with a coupling portion for coupling image light into the waveguide layer 41, The coupling part specifically includes a first optical element 410 disposed on the side of the first preset area of ​​the waveguide layer 41 far away from the imaging device 40 and a second optical element disposed on the side of the first preset area of ​​the waveguide layer 41 close to the imaging device 40 411.

[0055] Preferably, the coupling part of the waveguide layer 41 can realize that the image light propagating from the imaging device 40 or the previous waveguide layer 41 passes through the second optical element and does not enter the current waveguide layer 41. The optical element is diffracted and the diffracted light enters the current waveguide layer 41 and propagates in the form of total reflection.

[0056] Further preferably, the coupling part of the waveguide layer 41 can realize: the image light propagated from the imaging device 40 or the previous waveguide layer 41 is diffracted by the second optical element of the current waveguide layer, and the diffracted light enters the current waveguide. In the layer 41, the diffracted light formed by the incident light reflected by the first optical element, diffracted by the second optical element, and diffracted by the first optical element in turn propagates in the current waveguide layer 41 in the form of total reflection.

[0057] Further preferably, the coupling part of the waveguide layer 41 can realize: the image light propagating from the imaging device 40 or the previous waveguide layer 41 is diffracted by the second optical element of the current waveguide layer 41, and the diffracted light enters the current In the waveguide layer 41, the incoming light is diffracted by the first optical element and the diffracted light is emitted to the subsequent waveguide layer 41. The outgoing light is diffracted by the second optical element of the subsequent waveguide layer 41 and the diffracted light enters the subsequent waveguide layer 41. Propagation in the form of total reflection; or/and, among the outgoing light rays passing through the second optical element of the latter waveguide layer 41 but not entering the latter waveguide layer 41, light rays passing through the first optical element diffracted, the second optical element diffracted, the first The diffracted light formed by the diffraction of the optical element propagates in the form of total reflection in the latter waveguide layer.

[0058] Further preferably, the coupling part of the waveguide layer 41 can realize: the image light propagating from the imaging device 40 or the previous waveguide layer 41 is diffracted by the second optical element of the current waveguide layer 41, and the diffracted light enters the current In the waveguide layer 41, the incoming light is sequentially reflected by the first optical element and diffracted by the second optical element. The diffracted light passes through the first optical element and exits to the subsequent waveguide layer 41. The outgoing light occurs in the second optical element of the subsequent waveguide layer 41. The diffracted and diffracted light enters the latter waveguide layer 41 and propagates in the form of total reflection; or/and, among the outgoing rays, the second optical element that passes through the latter waveguide layer 41 does not enter the latter waveguide layer 41 and passes through the first optical element. The element diffracts and the diffracted light enters the latter waveguide layer 41 and propagates in the form of total reflection.

[0059] Further preferably, the coupling part of the waveguide layer 41 can realize that the image light propagated from the imaging device 40 or the previous waveguide layer 41 does not enter the current waveguide layer when passing through the second optical element of the current waveguide layer 41 The light in 41 is diffracted by the first optical element and then diffracted by the second optical element. The diffracted light passes through the first optical element and exits to the subsequent waveguide layer 41. The exiting light is diffracted by the second optical element of the subsequent waveguide layer 41. The diffracted light enters the latter waveguide layer 41 and propagates in the form of total reflection; or/and, when the outgoing light passes through the second optical element of the latter waveguide layer 41, the light that does not enter the latter waveguide layer 41 sequentially passes through the first optical element. The diffracted light formed by element diffraction, second optical element diffraction, and first optical element diffraction propagates in the form of total reflection in the latter waveguide layer 41.

[0060] Further preferably, the coupling part of the waveguide layer 41 can realize that the image light propagated from the imaging device 40 or the previous waveguide layer 41 does not enter the current waveguide layer when passing through the second optical element of the current waveguide layer 41 The light in 41 is sequentially diffracted by the first optical element, reflected by the second optical element, and diffracted by the first optical element, and the diffracted light is emitted to the subsequent waveguide layer 41, and the emitted light is diffracted by the second optical element of the subsequent waveguide layer 41 The diffracted light enters the latter waveguide layer 41 and propagates in the form of total reflection; or/and, when the outgoing light passes through the second optical element of the latter waveguide layer 41, the light that does not enter the latter waveguide layer 41 passes through the first optical element. The element diffracts and the diffracted light enters the latter waveguide layer 41 and propagates in the form of total reflection.

[0061] In the specific implementation of the display device of this embodiment, any one or any of the above-mentioned various propagating optical paths can exist in each waveguide layer of the display device at the same time, so as to realize the waveguide transmission of the image light, which is compared with the existing ones. Compared with the waveguide-based display device, the waveguide efficiency can be greatly improved,

[0062] Illustratively, in the display device of this embodiment, if the second optical element of each waveguide layer adopts a transmissive optical element based on the principle of diffraction, and the first optical element of each waveguide layer adopts a reflective optical element based on the principle of diffraction, In this embodiment, there are at least ten types of optical paths propagating simultaneously in each waveguide layer of the display device (not considering the low light transmission energy situation). In the following, the ten optical paths that exist in the display device of this embodiment are described one by one in conjunction with the schematic diagram of the optical path. Among them, the display device includes two waveguide layers, namely, the first waveguide layer 51 and the second waveguide layer 52 as an example. The first predetermined area of ​​the waveguide layer 51 is provided with a first optical element 510 on the side away from the image projection device, and the first optical element 520 is provided on the first predetermined area of ​​the second waveguide layer 52 on the side away from the image projection device.

[0063] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the first optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is: the image light propagating from the imaging device or the previous waveguide layer is generated in the second optical element 511 of the first waveguide layer 51 The diffracted and diffracted light enters the first waveguide layer 51, and the incident light is reflected by the first optical element 510, diffracted by the second optical element 511, and diffracted by the first optical element 510. Spread by reflection. The optical path in the second waveguide layer 52 is: when the image light passes through the second optical element 511 of the first waveguide layer 51, the light that does not enter the first waveguide layer 51 and is transmitted from the first optical element 510 is transmitted in the second waveguide layer 51. The second optical element 521 of the layer 52 is diffracted and the diffracted light enters the second waveguide layer 52. The incoming light is sequentially reflected by the first optical element 520, diffracted by the second optical element 521, and diffracted by the first optical element 520. It propagates in the form of total reflection in the second waveguide layer 52.

[0064] Such as Figure 5 As shown, light 1 is the incident image light with 100% energy; light 2 is the 0-level light of light 1 on the first waveguide layer 51 and the second optical element 511, with energy 70%; light 4 is light 2 on the first waveguide layer 51 The 0-order light of the first optical element 510, the energy is 49%; the light 2'is the diffracted light of the light 1 on the first waveguide layer 51 the second optical element 511, the energy is 30%; the light 3'is the light 2'in the first The diffracted light of the first optical element 510 of the waveguide layer 51 has an energy of 9%; the light 4'is the 0-order light of the first optical element 510 of the first waveguide layer 51 and the energy is 21%; the light 5'is a light 4' The diffracted light of the second optical element 511 on the first waveguide layer 51 has an energy of 6.3%; the light 6'is the 0-order light of the second optical element 511 on the first waveguide layer 51 and the energy is 14.7%; The light 5'is the 0-order light of the first optical element 510 on the first waveguide layer 51, and the energy is 4.41%; the light 8'is the diffracted light of the light 5'on the first optical element 510 of the first waveguide layer 51, and the energy is 1.89%. 6'and 8'perform total reflection propagation in the first waveguide layer 51.

[0065] In the second waveguide layer 52, the ray 22 is the 0-level light of the ray 4 in the second optical element 521 of the second waveguide layer 52, with an energy of 34.3%; the ray 24 is the ray 22 in the second optical element 520 of the second waveguide layer 52 0-level light, energy 24.01%; light 22' is the diffracted light of light 4 on the second optical element 521 of the second waveguide layer 52, energy 14.7%; light 23' is light 22' on the first optical element of the second waveguide layer 52 520 diffracted light, energy 4.41%; light 24' is 0-order light of light 22' in the first optical element 520 of the second waveguide layer 52, energy 10.29%; light 25' is light 24' in the second waveguide layer 52 The diffracted light of the second optical element 521 has an energy of 3.087%; the light 26' is the 0-order light of the light 24' in the second waveguide layer 52 and the second optical element 521 has an energy of 7.203%; the light 27' is the light 25' in the second waveguide The 0-order light of the first optical element 520 of the layer 52 has an energy of 2.1609%; the light 28' is the diffracted light of the first optical element 520 of the second waveguide layer 52 by the light 25', the energy is 0.9261%, and the light 26', 28' is in the first optical element 520. In the waveguide layer 52, total reflection propagation takes place.

[0066] Please refer to Image 6 , Image 6 This is a schematic diagram of the second optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Figure 5 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: when the image light passes through the second optical element 511 of the first waveguide layer 51, the light that does not enter the first waveguide layer 51 and is transmitted from the first optical element 510 enters the second optical element 511. In the waveguide layer 52, the part of light that does not enter the second waveguide layer 52 when passing through the second optical element 521 is diffracted by the first optical element 520 and the diffracted light enters the second waveguide layer 52 and propagates in the form of total reflection.

[0067] Such as Image 6 As shown, in the second waveguide layer 52, the light 23 is the diffracted light of the light 22 on the first optical element 520 of the second waveguide layer 52, and the energy is 10.29%; the light 25 is the light 23 on the second optical element of the second waveguide layer 52 The diffracted light of 521 has an energy of 3.087%; the light 26 is the diffracted light of the first optical element 520 of the second waveguide layer 52 with an energy of 0.9261%; the light 27 is the diffracted light of the first optical element 520 of the second waveguide layer 52 0-level light, energy 2.1609%; light 28 is 0-level light of light 23 in the second optical element 521 of the second waveguide layer 52, energy 7.203%; light 29 is light 26 of the second optical element 521 in the second waveguide layer 52 Diffracted light, energy 0.27783%; light 210 is diffracted light of light 28 on the second optical element 520 of the second waveguide layer 52, energy 2.1609%; light 211 is the 0th order of light 26 on the second optical element 521 of the second waveguide layer 52 Light, energy 0.64827%; light 212 is 0-order light of light 28 on the second waveguide layer 52 and first optical element 520, energy 5.0421%; light 213 is diffracted light of light 29 on the second waveguide layer 52 and first optical element 520 , The energy is 0.083349%; the light 214 is the 0-level light of the first optical element 520 of the light 29 on the second waveguide layer 52, and the energy is 0.194481%. The light rays 211, 212, and 213 are totally reflected and propagated in the second waveguide layer 52.

[0068] Please refer to Figure 7 , Figure 7 This is a schematic diagram of the third optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Figure 5 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: ray 32' is the diffracted light of ray 3 on the second optical element 521 of the second waveguide layer 52, with an energy of 2.7%; ray 33' is ray 32' on the second waveguide layer 52 first optical The diffracted light of the element 520 has an energy of 0.81%; the light 34' is the 0-order light of the light 32' in the first optical element 520 of the second waveguide layer 2 with an energy of 1.89%. The light 34' is totally reflected and propagated in the second waveguide layer 52.

[0069] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the fourth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Figure 5 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: the light 32 is the 0-level light of the light 3'in the second optical element 521 of the second waveguide layer 52, and the energy is 6.3%; the light 33 is the light 32 in the second waveguide layer 52 first optical The diffracted light of the element 520 has an energy of 1.89%; the light 34 is the 0-order light of the light 32 on the second waveguide layer 52 of the first optical element 520, and the energy is 4.41%; the light 35 is a light 33 on the second optical element of the second waveguide layer 52 The diffracted light of 521 has an energy of 0.567%; the light 36 is the diffracted light of the first optical element 520 of the second waveguide layer 52 with an energy of 0.1701%; the light 37 is the diffracted light of the first optical element 520 of the second waveguide layer 52 The 0-level light has an energy of 0.3969%; the light 38 is the 0-level light of the light 33 on the second optical element 521 of the second waveguide layer 52, and the energy is 1.323%. The light rays 36 and 38 are totally reflected and propagated in the second waveguide layer.

[0070] Please refer to Picture 9 , Picture 9 This is a schematic diagram of the fifth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Figure 5 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: the light 42' is the diffracted light of the light 7'on the second optical element 521 of the second waveguide layer 52, and the energy is 0.567%. The light 42' is totally reflected and propagated in the second waveguide layer.

[0071] Please refer to Picture 10 , Picture 10 This is a schematic diagram of the sixth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Figure 5 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: ray 42 is the 0-level light of ray 7'in the second optical element 521 of the second waveguide layer 52, with an energy of 1.323%; ray 43 is ray 42 in the second waveguide layer 52 first optical The diffracted light of the element 520 has an energy of 0.3969%; the light 44 is the 0th order light of the first optical element 520 of the light 32 on the second waveguide layer 52, and has an energy of 0.9261%. The light rays 43 are totally reflected and propagated in the second waveguide layer 52.

[0072] Please refer to Picture 11 , Picture 11 This is the seventh optical path schematic diagram of the display device of this embodiment. The optical path in the first waveguide layer 51 is: the second optical element 511 of the first waveguide layer 51 in the image light propagating from the projection device or the previous waveguide layer The light that does not enter the first waveguide layer 51 at this time is diffracted by the first optical element 510 and the diffracted light enters the first waveguide layer 51 and propagates in the form of total reflection. The optical path in the second waveguide layer 52 is: the image light propagating from the imaging device or the previous waveguide layer is diffracted by the second optical element 511 of the first waveguide layer 51, and the diffracted light enters the first waveguide layer 51 and enters The light is diffracted by the first optical element 510 and the diffracted light is emitted to the second waveguide layer 52. The emitted light is diffracted by the second optical element 521 of the second waveguide layer 52 and the diffracted light enters the second waveguide layer 52 and propagates in the form of total reflection. .

[0073] Such as Picture 11 As shown, the optical path in the first waveguide layer 51 is: ray 2 is 0-level light of ray 1 in the first waveguide layer 51 and the second optical element 511, with an energy of 70%; ray 3 is incident light 2 in the first waveguide layer 51 The diffracted light of the first optical element 510 has an energy of 21%; the light 4 is the 0th order light of the light 2 on the first waveguide layer 51 and the energy of the first optical element 510 is 49%; the light 5 is the light 3 on the first waveguide layer 51 The energy of the diffracted light of the second optical element 511 is 6.3%; the light 6 is the diffracted light of the first optical element 510 on the first waveguide layer 51, and the energy is 1.89%; the light 7 is the light 5 on the first waveguide layer 51 The 0-level light of the first optical element 510 has an energy of 4.41%; the light 8 is the 0-level light of the light 3 in the first waveguide layer 51 and the energy of the second optical element 511 is 14.7%; the light 9 is the light 6 in the first waveguide layer 51 The energy of the diffracted light of the second optical element 511 is 0.567%; the light 10 is the diffracted light of the first optical element 510 of the light 8 on the first waveguide layer 51, the energy is 4.41%; the light 11 is the light 6 on the first waveguide layer 51 The 0-level light of the second optical element 511 has an energy of 1.323%; the light 12 is the 0-level light of the first optical element 510 on the first waveguide layer 51, and the energy is 10.29%; the light 13 is the light 9 on the first waveguide layer 51. The diffracted light of an optical element 510 has an energy of 0.1701%; the light 14 is 0-order light of the first optical element 510 of the first waveguide layer 51 with an energy of 0.3969%. The light rays 11, 12, and 13 are totally reflected and propagated in the first waveguide layer 51.

[0074] The optical path in the second waveguide layer 52 is: ray 52' is the diffracted light of ray 7 on the second optical element 521 of the second waveguide layer 52, with an energy of 1.323%; ray 53' is ray 52' first in the second waveguide layer 52 The diffracted light of the optical element 520 has an energy of 0.3969%; the light 54' is the 0-order light of the first optical element 520 of the light 52' on the second waveguide layer 52, and has an energy of 0.9261%. The light 54' is totally reflected and propagated in the second waveguide layer.

[0075] Please refer to Picture 12 , Picture 12 This is a schematic diagram of the eighth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Picture 11 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: ray 52 is 0-level light of ray 7 in the second optical element 521 of the second waveguide layer 52, with an energy of 3.087%; ray 53 is ray 52 in the second optical element of the second waveguide layer 52 The diffracted light of 520, the energy is 0.9261%; the light 54 is the 0-order light of the first optical element 520 of the light 52 on the second waveguide layer 52, and the energy is 2.1609%; the light 55 is the light 53 on the second optical element 521 of the second waveguide layer 52 The energy is 0.27783%; the light 56 ​​is the diffracted light of the light 55 on the second waveguide layer 52 and the first optical element 520, the energy is 0.083349%; the light 57 is the light 55 on the second waveguide layer 52 of the first optical element 520. Grade light, energy is 0.194481%; light 58 is 0 grade light of light 53 in the second optical element 521 of the second waveguide layer 52, and energy is 0.64827%. The light rays 56, 58 are totally reflected and propagated in the second waveguide layer.

[0076] Please refer to Figure 13 , Figure 13 This is a schematic diagram of the ninth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Picture 11 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: the light 62' is the diffracted light of the light 10 on the second optical element 521 of the second waveguide layer 52, and the energy is 1.323%; the light 63' is the light 62' first in the second waveguide layer 52 The diffracted light of the optical element 520 has an energy of 0.3969%; the light 64' is the 0-order light of the first optical element 520 of the light 62' on the second waveguide layer 52, and has an energy of 0.9261%. The light 64' is totally reflected and propagated in the second waveguide layer 52.

[0077] Please refer to Picture 14 , Picture 14 This is a schematic diagram of the tenth optical path of the display device of this embodiment. The optical path in the first waveguide layer 51 is Picture 11 The optical paths in the first waveguide layer 51 shown are the same. The optical path in the second waveguide layer 52 is: ray 62 is the 0-level light of ray 10 in the second optical element 521 of the second waveguide layer 52, with an energy of 3.087%; ray 63 is ray 62 in the second optical element of the second waveguide layer 52 The diffracted light of 520 has an energy of 0.9261%; the light 64 is 0-order light of the first optical element 520 of the light 62 on the second waveguide layer 52, and the energy is 2.1609%. The light 63 is totally reflected and propagated in the second waveguide layer.

[0078] by Figure 5 ~ Figure 14 It can be seen that the final output light of the display device of this embodiment is 6', 8', 26', 28', 211, 212, 213, 34', 36, 38, 42', 43, 11, 12, 13, 54', 56, 58, 64' and 63, the final output light energy total is about 51%, the coupling efficiency of the waveguide is 51%, that is, 51% of the energy light is coupled into the waveguide layer for transmission, which is different from the existing waveguide-based Compared with the display device, the waveguide efficiency is increased by 143%, which greatly improves the light energy utilization rate.

[0079] In the display device of the above specific implementation, the second optical element of each waveguide layer adopts a transmissive optical element based on the principle of diffraction, and the first optical element of each waveguide layer adopts a reflective optical element based on the principle of diffraction. Yes, the second optical element of each waveguide layer can also be a reflective optical element based on the principle of diffraction, and the first optical element of each waveguide layer can be a transmissive optical element based on the principle of diffraction. Please refer to Figure 15 with Figure 16 , Figure 15 The first optical element that is the waveguide layer is a schematic diagram of the optical path of a reflective optical element based on the principle of diffraction, Figure 16 The second optical element that is the waveguide layer is a schematic diagram of the optical path of the transmissive optical element based on the principle of diffraction. In this implementation mode, the image light is coupled into the waveguide layer through the first optical element and the second optical element. The optical path of the element and the second optical element are realized accordingly.

[0080] In this example, please refer to Figure 4 As shown, the first optical element 410 of each waveguide layer 41 may be a reflective optical element based on the principle of diffraction, or the first optical element 410 of each waveguide layer 41 may be a transmissive optical element based on the principle of diffraction. Alternatively, the first optical elements 410 of several waveguide layers in the first to Nth waveguide layers 41 are reflective optical elements based on the principle of diffraction, and the first optical elements 410 of other waveguide layers are transmissive optical elements based on the principle of diffraction.

[0081] The second optical element 411 of each waveguide layer 41 may be a reflective optical element based on the principle of diffraction, or the second optical element 411 of each waveguide layer may be a transmissive optical element based on the principle of diffraction. Alternatively, the second optical elements 411 of several waveguide layers in the first to Nth waveguide layers 41 are reflective optical elements based on the principle of diffraction, and the second optical elements 411 of other waveguide layers are transmissive optical elements based on the principle of diffraction.

[0082] Please refer to Figure 4 The second preset area of ​​each waveguide layer 41 is provided with an out-coupling portion 412 for coupling the image light propagating in the waveguide layer 41 out of the waveguide layer 41, and the image light coupled into the waveguide layer 41 is in the waveguide layer. The image light propagates in the form of total reflection, and the image light propagates in the turning area of ​​the waveguide layer in the form of total reflection. When it travels to the second preset area, it is coupled out by the coupling-out portion 412. The image light coupled out of each waveguide layer 41 enters the user's eyes. And realize the display. The coupling-out portion 412 may be an optical element based on the principle of diffraction. In this embodiment, specifically, the coupling-out portion 412 is provided on the second predetermined area of ​​each waveguide layer 41 far away from the user's viewing side.

[0083] Preferably, the projections of the second preset regions of the respective waveguide layers 41 along the arrangement direction of the waveguide layers 41 do not overlap each other, or the projections of the second preset regions of the respective waveguide layers 41 along the arrangement direction of the waveguide layers partially overlap. It is to prevent the second preset areas of each waveguide layer from completely overlapping. If the second preset areas of two waveguide layers completely overlap, the light coupled out of the latter waveguide layer will be incident on the second preset area of ​​the previous waveguide layer. It is coupled out of the optical element and re-coupled into the waveguide layer, so that the light is coupled out as much as possible through the above arrangement, and the light is coupled out as much as possible to enter the user's eyes, which improves the efficiency of the waveguide and improves the light energy utilization rate.

[0084] The above has described in detail a display device provided by the present invention. Specific examples are used in this article to illustrate the principle and implementation of the present invention. The description of the above examples is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.