A waveguide display system and a display device

Abstract

The present invention discloses a waveguide display system and a display device. The waveguide display system includes: a first waveguide sheet and a second waveguide sheet. The first waveguide sheet includes a first coupling unit, and the second waveguide sheet includes a second coupling unit. Among them, the first coupling unit and the second coupling unit are located on the same side. The first coupling unit is used to couple light into the first waveguide sheet. A part of the light undergoes total internal reflection in the first waveguide sheet and then enters the first waveguide sheet for transmission, and another part undergoes reflection and refraction to form a reflected light and a refracted light. The refracted light is incident on the second coupling unit through the lower surface of the first waveguide sheet. The second coupling unit is used to couple the refracted light into the second waveguide sheet. The refracted light undergoes total internal reflection in the second waveguide sheet and then enters the second waveguide sheet for transmission. Thus, the division of the picture can be realized, and the picture division is relatively clean and has high efficiency. In addition, the light energy utilization efficiency can be improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of optical waveguides, and in particular, to a waveguide display system and a display device. Background Art

[0002] Based on a near-eye display module with an optical waveguide (planar glass substrate), relying on the principle of total internal reflection of light in a medium, the light is laterally transmitted inside the waveguide sheet, thereby increasing the distance between the projection module and the human eye's line of sight axis and improving the wearing comfort of the near-eye display module. In order to increase the field of view angle of the optical waveguide near-eye display module, the waveguide sheets can be stacked in multiple layers, and each layer forms a picture of different regions in the field of view. The multiple layers of waveguides are spliced into one picture. One way is to use different screens to display different contents, and finally debug and splice them. The disadvantage is that the number of screens is increased, the occupied space is large, and the cost is also high. Another way is to use a polarization beam splitter prism to import the same picture in layers. The picture information imported by the two waveguide sheets is the same. According to the layering principle, each layer needs to display different parts of the same picture, and finally a splicing effect is formed. However, the light in the parts that are not displayed is wasted, which affects the final brightness entering the eyes and reduces the overall efficiency of the system. Summary of the Invention

[0003] The present invention provides a waveguide display system and a display device, so as to realize improving the light energy utilization efficiency on the basis of dividing the picture.

[0004] To achieve the above object, an embodiment of one aspect of the present invention provides a waveguide display system, including:

[0005] A first waveguide sheet and a second waveguide sheet, the first waveguide sheet includes a first coupling unit, and the second waveguide sheet includes a second coupling unit, wherein the first coupling unit and the second coupling unit are located on the same side;

[0006] The first coupling unit is used to couple light into the first waveguide sheet. A part of the light undergoes total internal reflection in the first waveguide sheet and then enters the first waveguide sheet for transmission, and another part undergoes reflection and refraction to form a reflected light and a refracted light. The refracted light is incident on the second coupling unit through the lower surface of the first waveguide sheet. The second coupling unit is used to couple the refracted light into the second waveguide sheet, and the refracted light undergoes total internal reflection in the second waveguide sheet and then enters the second waveguide sheet for transmission.

[0007] According to an embodiment of the present invention, the first coupling unit couples light into the first waveguide sheet, wherein the incident angle of a part of the light into the first waveguide sheet is greater than or equal to the total reflection angle of the first waveguide sheet; the incident angle of another part of the light into the first waveguide sheet is less than the total reflection angle of the first waveguide sheet.

[0008] According to an embodiment of the present invention, the second coupling unit includes a first mirror, and the first mirror is configured to reflect the refracted light into the second waveguide sheet and adjust the incident angle of the refracted light into the second waveguide sheet.

[0009] According to an embodiment of the present invention, the incident angle of the first mirror reflecting the refracted light into the second waveguide sheet is greater than or equal to the total reflection angle of the second waveguide sheet.

[0010] According to an embodiment of the present invention, the first mirror is an array of mirrors.

[0011] According to an embodiment of the present invention, the waveguide display system further includes: a second mirror, the second mirror is located on the upper surface of the first waveguide sheet, and the second mirror is configured to reflect the reflected light to the lower surface of the first waveguide sheet.

[0012] According to an embodiment of the present invention, the first waveguide sheet further includes a first coupling-out unit, the first coupling-out unit includes an array of interfaces, and the first coupling-out unit is configured to couple out a part of the light.

[0013] According to an embodiment of the present invention, the second waveguide sheet further includes a second coupling-out unit, the second coupling-out unit includes an array of interfaces, and the second coupling-out unit is configured to couple out the refracted light of another part of the light.

[0014] To achieve the above object, another embodiment of the present invention further provides a display device, including the waveguide display system as described above;

[0015] It further includes: a projection system, and the projection system is configured to emit light to the waveguide display system.

[0016] A waveguide display system and a display device according to an embodiment of the present invention. The waveguide display system includes: a first waveguide sheet and a second waveguide sheet. The first waveguide sheet includes a first coupling unit, and the second waveguide sheet includes a second coupling unit. The first coupling unit and the second coupling unit are located on the same side. The first coupling unit is configured to couple light into the first waveguide sheet. A part of the light undergoes total internal reflection in the first waveguide sheet and then propagates in the first waveguide sheet, while another part is reflected and refracted to form a reflected light and a refracted light. The refracted light enters the second coupling unit through the lower surface of the first waveguide sheet. The second coupling unit is configured to couple the refracted light into the second waveguide sheet. The refracted light undergoes total internal reflection in the second waveguide sheet and then enters the second waveguide sheet for propagation. Thus, the division of the picture can be realized, and the picture division is relatively clean and efficient. In addition, the light energy utilization efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a waveguide display system in the prior art;

[0018] Figure 2 is a schematic structural diagram of another waveguide display system in the prior art;

[0019] Figure 3 is a schematic structural diagram of yet another waveguide display system in the prior art;

[0020] Figure 4 is a schematic structural diagram of a waveguide display system according to an embodiment of the present invention;

[0021] Figure 5 is an imaging schematic diagram of a waveguide display system according to an embodiment of the present invention;

[0022] Figure 6 is a schematic structural diagram of a waveguide display system according to an embodiment of the present invention;

[0023] Figure 7 is a schematic structural diagram of a waveguide display system according to another embodiment of the present invention;

[0024] Figure 8 is a schematic structural diagram of a waveguide display system according to yet another embodiment of the present invention;

[0025] Figure 9 is a schematic structural diagram of a waveguide display system according to still another embodiment of the present invention;

[0026] Figure 10 is a block schematic diagram of a display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for ease of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0028] Figure 1 is a schematic structural diagram of a waveguide display system in the prior art. As Figure 1 shown, the waveguide display system includes a first image display 51, a first collimator 52, a first waveguide sheet 53, a second image display 54, a second collimator 55, and a second waveguide sheet 56. Among them, the first image display 51 displays a first sub-image and emits a first light beam. After being processed by the first collimator 52, the first light beam becomes collimated light, and then is coupled into the first waveguide sheet 53, and finally forms a first coupled-out light beam coupled out from the first waveguide sheet 53. The first coupled-out light beam reaches the human eye retina to complete the imaging of the first sub-image. The second image display 54 displays a second sub-image and emits a second light beam. After being processed by the second collimator 55, the second light beam becomes collimated light, and then is coupled into the second waveguide sheet 56, and finally forms a second coupled-out light beam coupled out from the second waveguide sheet 56. The second coupled-out light beam reaches the human eye retina to complete the imaging of the second sub-image.

[0029] Figure 2 is a schematic structural diagram of another waveguide display system in the prior art. As Figure 2 shown, the waveguide display system includes a first image display 61, a first collimator 62, a first waveguide sheet 63, a second image display 64, a second collimator 65, and a second waveguide sheet 66. Among them, the first image display 61 displays a first sub-image and emits a first light beam. After being processed by the first collimator 62, the first light beam becomes collimated light, and then is coupled into the first waveguide sheet 63, and finally forms a first coupled-out light beam coupled out from the first waveguide sheet 63. The first coupled-out light beam reaches the human eye retina to complete the imaging of the first sub-image. The second image display 64 displays a second sub-image and emits a second light beam. After being processed by the second collimator 65, the second light beam becomes collimated light, and then is coupled into the second waveguide sheet 66, and finally forms a second coupled-out light beam coupled out from the second waveguide sheet 66. The second coupled-out light beam reaches the human eye retina to complete the imaging of the second sub-image.

[0030] Among them, Figure 1 and Figure 2 the embodiments shown have the disadvantages of increasing the number of screens, occupying a large space, and having a high cost.

[0031] Figure 3 is a schematic structural diagram of yet another waveguide display system in the prior art. As Figure 3As shown in the figure, the waveguide display system includes an image display 71, a first beam splitting unit 72, a polarization modulation unit 73, a collimation unit 74, a second beam splitting unit 75, a first prism 76, a second prism 77, a first waveguide substrate 78, and a second waveguide substrate 79. Among them, the image display 71 sequentially displays a first sub-image and a second sub-image, emits a first light beam when displaying the first sub-image, and emits a second light beam when displaying the second sub-image; the first beam splitting unit 72 splits the first light beam and the second light beam into P-polarized light; the polarization modulation unit 73 directly transmits the first light beam of P-polarized light, and deflects the second light beam of P-polarized light into S-polarized light and then transmits it; the collimation unit 74 processes the first light beam of P-polarized light and the second light beam of S-polarized light into collimated light; the second beam splitting unit 75 directly transmits the first light beam that becomes collimated light and is P-polarized, and reflects the second light beam that becomes collimated light and is S-polarized; the first prism 76 couples the first light beam that becomes collimated light and is P-polarized into the first waveguide substrate 78; the second prism 77 couples the second light beam that becomes collimated light and is S-polarized into the second waveguide substrate 79.

[0032] Figure 3 In the embodiment shown, the picture information introduced by the two-layer waveguide sheet is the same. According to the layering principle, each layer needs to display different parts of the same picture, and finally a splicing effect is formed. However, the light in the parts that are not displayed is wasted, which affects the final brightness entering the eyes and reduces the overall efficiency of the system.

[0033] Figure 4 is a schematic structural diagram of the waveguide display system proposed in the embodiment of the present invention. As Figure 4 shown, the waveguide display system 100 includes:

[0034] A first waveguide sheet 101 and a second waveguide sheet 102, the first waveguide sheet 101 includes a first coupling unit 103, and the second waveguide sheet 102 includes a second coupling unit 104, wherein the first coupling unit 103 and the second coupling unit 104 are located on the same side;

[0035] The first coupling unit 103 is used to couple light into the first waveguide sheet 101. A part of the light undergoes total internal reflection in the first waveguide sheet 101 and then transmits in the first waveguide sheet 101, and the other part undergoes reflection and refraction to form a reflected light beam and a refracted light beam. The refracted light beam enters the second coupling unit 104 through the lower surface of the first waveguide sheet 101. The second coupling unit 104 is used to couple the refracted light beam into the second waveguide sheet 102, and the refracted light beam undergoes total internal reflection in the second waveguide sheet 102 and then enters the second waveguide sheet 102 for transmission.

[0036] It should be noted that the first coupling unit 103 couples light into the first waveguide sheet 101, and for a part of the light, the incident angle into the first waveguide sheet 101 is greater than or equal to the total reflection angle of the first waveguide sheet 101; for another part of the light, the incident angle into the first waveguide sheet 101 is less than the total reflection angle of the first waveguide sheet 101.

[0037] That is to say, the light coupled by the first coupling unit 103 includes two parts. For one part of the light, the incident angle is greater than or equal to the total reflection angle of the first waveguide sheet 101, and for the other part of the light, the incident angle is less than the total reflection angle of the first waveguide sheet 101. The light with an incident angle greater than or equal to the total reflection angle of the first waveguide sheet 101 undergoes total reflection in the first waveguide sheet 101 and enters the first waveguide sheet 101 for transmission. The light with an incident angle less than the total reflection angle of the first waveguide sheet 101 undergoes reflection and refraction in the first waveguide sheet 101 to form reflected light and refracted light. The refracted light is coupled into the second waveguide sheet 102 through the second coupling unit of the second waveguide sheet 102 and is transmitted in the second waveguide sheet 102. Thus, the first waveguide sheet 101 and the second waveguide sheet 102 divide the coupled light into two parts with the total reflection angle of the first waveguide sheet 101 as the boundary. Finally, the two parts of the light are respectively imaged to form two images (as Figure 5 shown), and then spliced together. In this way, on the basis of reducing optical devices (without using two display screens), the division of the picture can still be achieved, and the light beams used for final imaging only overlap at the total reflection angle (such as the middle line in Figure 5 ), and there is no overlap elsewhere. All the light is used for imaging, improving the light utilization efficiency.

[0038] According to an embodiment of the present invention, as Figure 6 shown, the second coupling unit 104 includes a first mirror 105, and the first mirror 105 is used to reflect the refracted light into the second waveguide sheet 102 and adjust the incident angle of the refracted light into the second waveguide sheet 102.

[0039] According to an embodiment of the present invention, the incident angle at which the first mirror 105 reflects the refracted light into the second waveguide sheet 102 is greater than or equal to the total reflection angle of the second waveguide sheet 102.

[0040] It should be noted that the first mirror 105 can adjust the incident angle of the refracted light incident on the lower surface of the second waveguide plate 102. In the actual operation process, the installation angle of the first mirror 105 can be determined according to the requirement of the incident angle of the refracted light incident on the lower surface of the second waveguide plate 102 and the incident angle of the refracted light incident on the first mirror 105, and only needs to satisfy that the incident angle of the refracted light incident on the lower surface of the second waveguide plate 102 is greater than or equal to the total reflection angle of the second waveguide plate 102. Thus, after the refracted light enters the second waveguide plate 102, total internal reflection occurs inside the second waveguide plate 102 and is transmitted in the second waveguide plate 102. Based on this, the refracted light of the light with an incident angle less than the total reflection angle of the first waveguide plate 101 is used for imaging to a large extent, improving the light energy utilization rate.

[0041] According to an embodiment of the present invention, as Figure 7 shown, the first mirror 105 is an array of mirrors.

[0042] Among them, Figure 7 in the second coupling unit, three first mirrors 105 are included. It can be understood that the light with an incident angle less than the total reflection angle of the first waveguide plate 101 is refracted for the first time on the lower surface of the first waveguide plate 101 to form a first refracted light, and the first refracted light is reflected by the first mirror 105 (the rightmost first mirror among the three) to the second waveguide plate 102; in addition, the light with an incident angle less than the total reflection angle of the first waveguide plate 101 is reflected for the first time on the lower surface of the first waveguide plate 101 to form a first reflected light, the first reflected light is incident on the upper surface of the first waveguide plate 101, and is reflected by the upper surface of the first waveguide plate 101, then is incident on the lower surface of the first waveguide plate 101 and is refracted again to form a second refracted light, and the second refracted light is reflected by the first mirror 105 (the middle first mirror among the three) to the second waveguide plate 102; and so on, the light with an incident angle less than the total reflection angle of the first waveguide plate 101 is reflected in the first waveguide plate 101 and is refracted on the lower surface of the first waveguide plate 101, and the refracted light all enters the second waveguide plate 102 through the first mirror 105. It should be noted that after the light with an incident angle less than the total reflection angle of the first waveguide plate 101 is reflected in the first waveguide plate 101 several times, the light energy loss is relatively large, and the energy of the refracted light after that can be almost ignored. Therefore, generally, only three to five first mirrors 105 are provided in the second coupling unit 104 of the second waveguide plate 102.

[0043] According to an embodiment of the present invention, as Figure 8As shown, the waveguide display system 100 further includes: a second mirror 106, which is located on the upper surface of the first waveguide sheet 101, and the second mirror 106 is used to reflect the reflected light to the lower surface of the first waveguide sheet 101.

[0044] It can be understood that light rays with an incident angle less than the total reflection angle of the first waveguide sheet 101 are reflected in the first waveguide sheet 101. To avoid energy loss, that is, to avoid refraction of light rays on the upper surface of the first waveguide sheet 101, a second mirror 106 is provided on the upper surface of the first waveguide sheet 101. The second mirror 106 causes the reflected light rays to be reflected again without refraction (transmission). Thus, the light energy utilization rate is further improved. It should be noted that light rays with an incident angle less than the total reflection angle of the first waveguide sheet 101 are reflected in the first waveguide sheet 101. After several reflections, the light energy loss is relatively large, and the energy of the reflected light rays after that can be almost ignored. Therefore, the second mirror 106 is only provided in the first coupling unit 103 of the first waveguide sheet 101.

[0045] In addition, a reflective coating can also be applied to the upper surface of the first waveguide sheet 101 to avoid the transmission of reflected light rays.

[0046] According to an embodiment of the present invention, as Figure 9 shown, the first waveguide sheet 101 further includes a first coupling-out unit 107, and the first coupling-out unit 107 includes interfaces arranged in an array. The first coupling-out unit 107 is used to couple out a part of the light rays.

[0047] It can be understood that light rays with an incident angle greater than or equal to the total reflection angle of the first waveguide sheet 101 are totally reflected in the first waveguide sheet 101, are conducted through the first waveguide sheet 101, enter the first coupling-out unit 107, and are reflected by the interfaces in the first coupling-out unit 107 to form a first coupling-out light beam. The statement that the first coupling-out unit 107 is used to couple out a part of the light rays means that the first coupling-out unit 107 couples out light rays with an incident angle greater than or equal to the total reflection angle of the first waveguide sheet 101.

[0048] According to an embodiment of the present invention, as Figure 9 shown, the second waveguide sheet further includes a second coupling-out unit 108, and the second coupling-out unit 108 includes interfaces arranged in an array. The second coupling-out unit 108 is used to couple out the refracted light rays of another part of the light rays.

[0049] It can be understood that light rays with an incident angle smaller than the total reflection angle of the first waveguide sheet 101 are reflected and refracted in the first waveguide sheet 101. The refracted light rays are conducted through the second waveguide sheet 102 and enter the second output unit 108, where they are reflected at the interface in the second output unit 108 to form a second output light beam. The statement that the second output unit 108 is used to output another part of the light rays means that the second output unit 108 outputs the light rays with an incident angle smaller than the total reflection angle of the first waveguide sheet 101, which are the refracted light rays refracted at the lower surface of the first waveguide sheet 101.

[0050] It should be noted that in the output part, the direction of the first output light beam is different from that of the second output light beam. And a coating can be applied to the reverse side of the interface arranged in an array in the output part to prevent the light transmitted through the interface from being reflected by the waveguide sheet and then reflected back to the interface, and then reflected through this interface to the front of the next interface, so as to avoid the light rays in the output light beam being doped with the light reflected by the interface, thereby further improving the image clarity.

[0051] Based on this, the waveguide display system proposed in the embodiments of the present invention can not only significantly increase the viewing angle, but also improve the light energy utilization rate and avoid waste of light energy. In addition, the number of displays used is reduced, saving costs. And the picture division is relatively clean and efficient. Especially for the picture in the second waveguide sheet 102, according to the principle of total reflection, the light rays that meet the total reflection conditions cannot be exported from the first waveguide sheet 101, so the light rays that meet the total reflection conditions do not appear in the second waveguide sheet 102. For the first waveguide sheet 101, some light rays that do not meet the total reflection angle are partially reflected back to the first waveguide sheet 101, and the efficiency can be improved by Figure 9 the way of multiple outputs.

[0052] Figure 10 is a schematic block diagram of the display device further proposed in the embodiments of the present invention. As Figure 10 shown, the display device 200 includes the waveguide display system 100 as described above;

[0053] It further includes: a projection system 300, which is used to emit light rays to the waveguide display system 100; the light rays output by the waveguide display system 100 reach the human eye retina to complete imaging.

[0054] In summary, according to the waveguide display system and the display device proposed in the embodiments of the present invention, the waveguide display system includes: a first waveguide sheet and a second waveguide sheet. The first waveguide sheet includes a first coupling unit, and the second waveguide sheet includes a second coupling unit. Among them, the first coupling unit and the second coupling unit are located on the same side; the first coupling unit is used to couple light into the first waveguide sheet. A part of the light undergoes total internal reflection in the first waveguide sheet and then enters the first waveguide sheet for transmission, and another part undergoes reflection and refraction to form a reflected light and a refracted light. The refracted light is incident on the second coupling unit through the lower surface of the first waveguide sheet. The second coupling unit is used to couple the refracted light into the second waveguide sheet, and the refracted light undergoes total internal reflection in the second waveguide sheet and then enters the second waveguide sheet for transmission. Thus, the division of the picture can be realized, and the picture division is relatively clean and efficient. In addition, the light energy utilization efficiency can be improved.

[0055] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A waveguide display system, characterized in that, include: a first waveguide plate and a second waveguide plate, wherein the first waveguide plate includes a first coupling unit and the second waveguide plate includes a second coupling unit, wherein the first coupling unit and the second coupling unit are located on the same side; The first coupling unit is used to couple light into the first waveguide plate, where a portion of the light is totally reflected in the first waveguide plate and then enters the first waveguide plate for transmission, while the other portion is reflected and refracted to form reflected light and refracted light. The refracted light is incident on the second coupling unit through the lower surface of the first waveguide plate. The second coupling unit is used to couple the refracted light into the second waveguide plate, where the refracted light is totally reflected in the second waveguide plate and then enters the second waveguide plate for transmission; The first coupling unit couples light into the first waveguide, wherein a portion of the light is incident on the first waveguide at an angle greater than or equal to a total internal reflection angle of the first waveguide; and another portion of the light is incident on the first waveguide at an angle less than a total internal reflection angle of the first waveguide. The first coupling unit of the first waveguide plate includes a first inclined surface, and the second coupling unit of the second waveguide plate includes a second inclined surface. The upper surface of one end surface of the first waveguide plate is shorter than the lower surface, so as to form the first inclined surface. The upper surface of the end surface of the second waveguide plate on the same side as the first waveguide plate is longer than the lower surface, so as to form the second inclined surface. The upper surface of the second waveguide plate is adjacent to the lower surface of the first waveguide plate, and the length of the second waveguide plate is shorter than that of the first waveguide plate. The second coupling unit includes a first reflector, the first reflector is used to reflect the refracted light into the second waveguide plate and adjust the incident angle of the refracted light into the second waveguide plate; The second waveguide plate further includes a second outcoupling unit, the second outcoupling unit includes an array-arranged interface, and the second outcoupling unit is used to couple out the refracted light of another part of the light; The invention further comprises: a second reflector, the second reflector being located on the upper surface of the first waveguide plate, and the second reflector being configured to reflect the reflected light to the lower surface of the first waveguide plate; The first reflector reflects the refracted light into the second waveguide at an incident angle greater than or equal to a total reflection angle of the second waveguide; The first reflectors are reflectors arranged in an array.

2. The waveguide display system according to claim 1, wherein The first waveguide plate further includes a first outcoupling unit, the first outcoupling unit includes an array-arranged interface, and the first outcoupling unit is used to couple out a portion of the light.

3. A display device, characterized in that, comprising a waveguide display system as claimed in claim 1 or 2; It also includes: a projection system, which is used to emit light to the waveguide display system.

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