Near-to-eye display module

Abstract

The embodiment of the invention discloses a near-to-eye display module, which comprises a one-dimensional optical waveguide and an optical machine, and is characterized in that the one-dimensional optical waveguide comprises a coupling-in area and a coupling-out area; the optical machine is arranged towards the coupling-in area of the one-dimensional optical waveguide; the ray machine comprises a display screen and a turn-back imaging system, the turn-back imaging system is located on the light emitting side of the display screen, and the display screen is located on an object space focal plane of the turn-back imaging system; the turn-back imaging system comprises a first turn-back surface and a second turn-back surface which are arranged along an optical axis, and at least part of light emitted from any position on the display screen is transmitted to the second turn-back surface through the first turn-back surface, reflected to the first turn-back surface through the second turn-back surface and reflected to the second turn-back surface through the first turn-back surface in sequence. And the light is transmitted to the coupling area of the one-dimensional optical waveguide through the second turn-back surface. According to the embodiment of the invention, the problems that the coupled optical machine of the one-dimensional optical waveguide is heavy, small in field angle and the like can be solved, the eyestrain of a user can be reduced, and the experience feeling of the user in actual use is effectively improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of display technology, and in particular to a near-eye display module. Background Art

[0002] In the existing one-dimensional optical waveguide coupling optical machine, the coupling part usually adopts a straight-through multi-lens or TIR prism turning light path solution. The multi-lens solution usually adopts a glass, glass-plastic mixed or pure plastic structure, but the structure is large in size and heavy in weight, and the achievable field of view is also very limited, which cannot meet the requirements of lightweight wearing; the TIR prism solution can achieve a small size and achieve lightweight requirements, but it usually needs to match a free-form surface, and the processing cost is relatively high. In addition, since the TIR prism is difficult to correct chromatic aberration, the chromatic aberration of complex light is large, which affects the actual viewing experience; and the existing one-dimensional waveguide coupling optical machine is difficult to avoid the obvious disadvantages of large size and heavy weight when in order to meet the large field of view, which reduces the consumer experience in actual use.

[0003] In general, the existing one-dimensional optical waveguide coupling optical machine cannot be compatible with the advantages of small size, large field of view, small aberration, large pupil, etc. When worn for a long time, lightness becomes the most important feature. Summary of the invention

[0004] The present invention provides a near-eye display module to solve the problems of bulkiness and small viewing angle of a one-dimensional optical waveguide coupling optical machine.

[0005] In a first aspect, an embodiment of the present invention provides a near-eye display module, comprising:

[0006] A one-dimensional optical waveguide, the one-dimensional optical waveguide comprising an incoupling region and an outcoupling region, the incoupling region and the outcoupling region are arranged in a first direction, and the first direction is a pupil expansion direction of the one-dimensional optical waveguide;

[0007] An optical machine is arranged toward the coupling-in region of the one-dimensional optical waveguide; the optical machine comprises a display screen and a reentrant imaging system, the reentrant imaging system is located at the light-emitting side of the display screen, and the display screen is located on the object focal plane of the reentrant imaging system;

[0008] The refraction imaging system comprises a first refraction surface and a second refraction surface arranged along the optical axis, and at least part of the light emitted from any position on the display screen is sequentially transmitted through the first refraction surface to the second refraction surface, reflected through the second refraction surface to the first refraction surface, reflected through the first refraction surface to the second refraction surface, and transmitted through the second refraction surface to the coupling-in region of the one-dimensional optical waveguide.

[0009] Optionally, the folding imaging system comprises a lens subsystem, the lens subsystem comprises at least a first lens, the first folding surface is located on the object side surface of the first lens, and the second folding surface is located on the image side surface of the first lens;

[0010] The first folding surface includes a first transmission area and a first reflection area, and the first reflection area surrounds the first transmission area; the second folding surface includes a second transmission area and a second reflection area, and the second transmission area surrounds the second reflection area;

[0011] Along the optical axis direction, the projection of the display screen is located in the projection of the first transmission area, and the projection of the first transmission area is located in the projection of the second reflection area;

[0012] At least part of the light emitted from any position on the display screen is sequentially transmitted through the first transmission area to the second reflection area, reflected through the second reflection area to the first reflection area, reflected through the first reflection area to the second transmission area, and transmitted through the second transmission area to the coupling-in area of ​​the one-dimensional optical waveguide.

[0013] Optionally, the first transmission area of ​​the object-side surface of the first lens is provided with a first transmission film, and the first reflection area is provided with a first reflection film;

[0014] The second transmission area of ​​the image-side surface of the first lens is provided with a second transmission film, and the second reflection area is provided with a second reflection film.

[0015] Optionally, the reentry imaging system comprises a first plane and a second plane, the first plane and the second plane are perpendicular to each other and intersect at the optical axis of the reentry imaging system;

[0016] The first transmission area, the first reflection area, the second transmission area and the second reflection area are all self-symmetrical relative to the first plane, and are all self-symmetrical relative to the second plane; wherein:

[0017] h>A; H21c1<H / 2<H21a2;

[0018] Wherein, A is the length of the intersection line between the display screen and the first plane;

[0019] h is the length of the intersection line between the first transmission area and the first plane, and H is the length of the intersection line between the second reflection area and the first plane;

[0020] H21c1 is the distance between the point of the third edge projection area in the first plane that is closest to the optical axis and the optical axis, and the third edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface for the first time;

[0021] H21a2 is the distance between the point of the fourth edge projection area in the first plane that is farthest from the optical axis and the optical axis; the fourth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface;

[0022] v>B;V21f1<V / 2<V21d2,and D<V<D0;

[0023] Wherein, B is the length of the intersection line between the display screen and the second plane;

[0024] v is the length of the intersection line between the first transmission area and the second plane, and V is the length of the intersection line between the second reflection area and the second plane;

[0025] V21f1 is the distance between the point of the seventh edge projection area in the second plane that is closest to the optical axis and the optical axis, and the seventh edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time;

[0026] V21d2 is the distance between the point of the eighth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the eighth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface;

[0027] D is the diameter of the field of view formed by the outgoing light beam at the center point of the display screen through the lens subsystem on the image focal plane; D0 is the diameter of the field of view formed by the outgoing light beam at the edge point on the display screen farthest from the center point through the lens subsystem on the image focal plane.

[0028] Optionally, H21c1<H / 2<H21c2, and h22c1<h / 2<h22c2; or, H21a1<H / 2<H21a2, h22a1<h / 2<h22a2;

[0029] H21c1 is the distance between the point of the third edge projection area in the first plane that is closest to the optical axis and the optical axis, and the third edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface for the first time;

[0030] H21c2 is the distance between the point of the fourth edge projection area in the first plane that is closest to the optical axis and the optical axis, and the fourth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface;

[0031] h22c1 is the distance between the point of the first edge projection area in the first plane that is closest to the optical axis and the optical axis, and the first edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the first returning surface for the first time;

[0032] h22c2 is the distance between the point of the second edge projection area in the first plane that is closest to the optical axis and the optical axis, and the second edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the first returning surface for the second time;

[0033] H21a1 is the distance between the point closest to the optical axis in the third edge projection area in the first plane and the optical axis;

[0034] H21a2 is the distance between the point farthest from the optical axis in the fourth edge projection area in the first plane and the optical axis;

[0035] h22a1 is the distance between the point farthest from the optical axis in the first edge projection area in the first plane and the optical axis;

[0036] h22a2 is the distance between the point farthest from the optical axis in the second edge projection area in the first plane and the optical axis.

[0037] Optionally, V21f1<V / 2<V21f2, and v22f1<v / 2<v22f2; or, V21d1<V / 2<V21d2, and v22d1<v / 2<v22d2;

[0038] V21f1 is the distance between the point of the seventh edge projection area in the second plane that is closest to the optical axis and the optical axis; the seventh edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time;

[0039] V21f2 is the distance between the point of the eighth edge projection area in the second plane that is closest to the optical axis and the optical axis; the eighth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time;

[0040] v22f1 is the distance between the point of the fifth edge projection area in the second plane that is closest to the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time;

[0041] v22f2 is the distance between the point of the sixth edge projection area in the second plane that is closest to the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface;

[0042] V21d1 is the distance between the point farthest from the optical axis in the seventh edge projection area in the second plane and the optical axis;

[0043] V21d2 is the distance between the point farthest from the optical axis in the eighth edge projection area in the second plane and the optical axis;

[0044] v22d1 is the distance between the point farthest from the optical axis in the fifth edge projection area in the second plane and the optical axis;

[0045] v22d2 is the distance between the point farthest from the optical axis in the sixth edge projection area in the second plane and the optical axis;

[0046] V11d1<V / 2<V11d2, and v12d1<v / 2<v12d2;

[0047] V11d1 is the distance between the point of the seventh central projection area in the second plane that is farthest from the optical axis and the optical axis; the seventh central projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time;

[0048] V11d2 is the distance between the point of the eighth central projection area in the second plane that is farthest from the optical axis and the optical axis; the eighth central projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface;

[0049] v12d1 is the distance between the point of the fifth central projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth central projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time;

[0050] v12d2 is the distance between the point farthest from the optical axis in the eighth central projection area in the second plane and the optical axis.

[0051] Optionally, 2mm<D<8mm, 2mm<D0<8mm.

[0052] Optionally, the projection shapes of the first transmission area and the second reflection area along the optical axis are the same, and are both rectangular, elliptical or irregular polygonal.

[0053] Optionally, the folded imaging system comprises a transmissive polarizer, a first quarter wave plate, a lens subsystem, a second quarter wave plate and a reflective polarizer arranged in sequence along the optical axis;

[0054] The lens subsystem at least includes a first lens, the first folding surface is located on the object side surface of the first lens; the first folding surface includes a first transmission area and a first reflection area, the first reflection area surrounds the first transmission area; the second folding surface is located on the reflective polarizer;

[0055] Along the optical axis direction, the projection of the display screen is located in the projection of the first transmission area;

[0056] At least part of the light emitted from any position on the display screen is sequentially transmitted through the transmission polarizer to form horizontal polarized light, transmitted through the first quarter-wave plate to form right-handed circularly polarized light, transmitted through the first transmission area, transmitted through the second quarter-wave plate to form horizontal polarized light, reflected through the reflective polarizer, transmitted through the second quarter-wave plate to form right-handed circularly polarized light, reflected through the first reflection area to form left-handed circularly polarized light, transmitted through the second quarter-wave plate to form vertically polarized light, and transmitted through the reflective polarizer to the coupling-in area of ​​the one-dimensional optical waveguide.

[0057] Optionally, the first transmission area of ​​the object-side surface of the first lens is provided with a first transmission film, and the first reflection area is provided with a first reflection film.

[0058] Optionally, the reentry imaging system comprises a first plane and a second plane, the first plane and the second plane are perpendicular to each other and intersect at the optical axis of the reentry imaging system;

[0059] The first transmission area and the first reflection area are both symmetrical relative to the first plane, and are also symmetrical relative to the second plane; wherein:

[0060] h>A; v>B;

[0061] Wherein, h is the length of the intersection line between the first transmission area and the first plane;

[0062] A is the length of the intersection line between the display screen and the first plane;

[0063] v is the length of the intersection line between the first transmission area and the second plane;

[0064] B is the length of the intersection line between the display screen and the second plane.

[0065] Optionally, h22c1<h / 2<h22c2; or, h22a1<h / 2<h22a2;

[0066] v22c1 is the distance between the point of the first edge projection area in the first plane that is closest to the optical axis and the optical axis; the first edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen on the first plane on the first returning surface for the first time;

[0067] h22c2 is the distance between the point of the second edge projection area in the plane closest to the optical axis and the optical axis; the second edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane for the second time on the first return surface;

[0068] h22a1 is the distance between the point of the first edge projection area in the plane that is farthest from the optical axis and the optical axis; the first edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane on the first returning surface for the first time;

[0069] h22a2 is the distance between the point of the second edge projection area in the plane that is farthest from the optical axis and the optical axis; the second edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane on the first return surface for the second time;

[0070] h12a1<h / 2<h12a2;

[0071] h12a1 is the distance between the point of the first central projection area in the plane that is farthest from the optical axis and the optical axis; the first central projection area is the projection area of ​​the outgoing light beam at the center point of the display screen in the plane on the first reflecting surface for the first time;

[0072] h12a2 is the distance between the point farthest from the optical axis in the second central projection area in the plane and the optical axis; the second central projection area is the second projection area of ​​the outgoing light beam from the center point of the display screen in the plane on the first returning surface.

[0073] Optionally, v22f1<v / 2<v22f2; or, v22d1<v / 2<v22d2;

[0074] v22f1 is the distance between the point of the fifth edge projection area in the second plane that is closest to the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time;

[0075] v22f2 is the distance between the point of the sixth edge projection area in the second plane that is closest to the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface;

[0076] v22d1 is the distance between the point of the fifth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time;

[0077] v22d2 is the distance between the point of the sixth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface;

[0078] v12d1<v / 2<v12d2;

[0079] v12d1 is the distance between the point of the fifth central projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth central projection area is the projection area of ​​the outgoing light beam from the center point of the display screen on the second plane on the first returning surface for the first time;

[0080] v12d2 is the distance between the point farthest from the optical axis in the eighth central projection area in the second plane and the optical axis; the eighth central projection area is the second projection area of ​​the outgoing light beam from the center point of the display screen on the second plane on the first returning surface.

[0081] Optionally, the first lens is a meniscus lens convex toward the display screen.

[0082] Optionally, the object-side surface or the image-side surface of the first lens is a spherical surface, an aspherical surface, a free-form surface or a diffractive surface.

[0083] Optionally, the reflective imaging system has positive optical power.

[0084] The technical solution of the embodiment of the present invention is provided in a near-eye display module, wherein the one-dimensional optical waveguide includes a coupling-in region and a coupling-out region, and the coupling-in region and the coupling-out region are arranged in a first direction, and the first direction is the pupil expansion direction of the one-dimensional optical waveguide; the optical machine is arranged toward the coupling-in region of the one-dimensional optical waveguide; the optical machine includes a display screen and a reentrant imaging system, the reentrant imaging system is located on the light emitting side of the display screen, and the display screen is located on the object focal plane of the reentrant imaging system; the reentrant imaging system includes a first reentrant surface and a second reentrant surface arranged along the optical axis, and at least part of the light emitted from any position on the display screen is sequentially transmitted to the second reentrant surface through the first reentrant surface, reflected to the first reentrant surface through the second reentrant surface, reflected to the second reentrant surface through the first reentrant surface, and transmitted to the coupling-in region of the one-dimensional optical waveguide through the second reentrant surface. The embodiments of the present invention solve the problem that the one-dimensional optical waveguide coupled optical machine is incompatible with the advantages of small size, large field of view angle, small aberration, large pupil, etc., and has the problems of being bulky and having a small field of view angle. The light reflection is achieved through a reflection imaging system, which reduces the distance between the display screen and the one-dimensional optical waveguide, reduces the size and weight of the optical machine, and at the same time increases the field of view angle, increases the pupil, reduces the user's eye fatigue, and effectively improves the user's experience during actual use. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is a schematic structural diagram of a near-eye display module provided by an embodiment of the present invention in an XOZ plane;

[0086] Figure 2 yes Figure 1 The schematic diagram of the structure of the near-eye display module in the YOZ plane is shown;

[0087] Figure 3 is a schematic structural diagram of another near-eye display module provided by an embodiment of the present invention in the YOZ plane;

[0088] Figure 4 and Figure 5 is a schematic diagram of the light beam return projection area on two planes provided by an embodiment of the present invention;

[0089] Figure 6-Figure 8 Schematic diagram of three folded size designs of near-eye display modules provided by an embodiment of the present invention;

[0090] Figure 9-13 Schematic diagram of five folded size designs of near-eye display modules provided by an embodiment of the present invention;

[0091] Fig.14 is a schematic diagram of an equivalent structure of another near-eye display module in the YOZ plane provided by an embodiment of the present invention;

[0092] Figure 15-Figure 20 It is a schematic diagram of six folded size designs of a near-eye display module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0093] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0094] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", "right" and the like described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second", etc. are only used for descriptive purposes and do not represent any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0095] The term “including” and its variations used in the present invention are open inclusions, that is, “including but not limited to.” The term “based on” means “based at least in part on.” The term “one embodiment” means “at least one embodiment.”

[0096] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or interdependence.

[0097] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0098] Figure 1 is a schematic structural diagram of a near-eye display module in the XOZ plane provided by an embodiment of the present invention, Figure 2 yes Figure 1 The schematic diagram of the structure of the near-eye display module in the YOZ plane is shown in FIG. Figure 1 and Figure 2 The near-eye display module includes a one-dimensional optical waveguide 10 and an optical machine 20; the one-dimensional optical waveguide 10 includes a coupling-in area 110 and a coupling-out area 120, the coupling-in area 110 and the coupling-out area 120 are arranged in a first direction X, and the first direction X is the pupil expansion direction of the one-dimensional optical waveguide 10; the optical machine 20 is arranged toward the coupling-in area 110 of the one-dimensional optical waveguide 10; the optical machine 20 includes a display screen 21 and a reentrant imaging system 22, the reentrant imaging system 22 is located on the light exit side of the display screen 21, and the display screen 21 is located on the object focal plane of the reentrant imaging system 22.

[0099] The reflective imaging system 22 includes a first reflective surface 221 and a second reflective surface 222 arranged along the optical axis. At least part of the light emitted from any position on the display screen 21 is transmitted through the first reflective surface 221 to the second reflective surface 222, reflected from the second reflective surface 222 to the first reflective surface 221, reflected from the first reflective surface 221 to the second reflective surface 222, and transmitted through the second reflective surface 222 to the coupling-in region 110 of the one-dimensional optical waveguide 10.

[0100] First, for ease of understanding, the three-dimensional space where the near-eye display module in this embodiment is located is defined by a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other, thereby forming an XOZ plane and a YOZ plane. Figure 1 This is a view of the near-eye display module in the XOZ plane. Figure 2 This is a view of the near-eye display module in the YOZ plane. Figure 1 and Figure 2 As shown, in the near-eye display module, the one-dimensional optical waveguide 10 is responsible for proportionally transferring the image projected by the optical machine 20, and then transmitting the image to the human eye, thereby achieving a virtual display effect. Those skilled in the art can understand that the one-dimensional optical waveguide 10 refers to an optical device that constrains the propagation of light in a single dimension, specifically, restricts the propagation of light in the first direction X, but has no restrictions in the second direction Y and the third direction Z. For the near-eye display module, the one-dimensional optical waveguide 10 can increase the field of view angle and the uniformity of the exit pupil, and its pupil expansion direction is the first direction X.

[0101] In the embodiment of the present invention, a display screen 21 and a reentrant imaging system 22 are provided in the optical machine 20. The display screen 21 is responsible for displaying images, while the reentrant imaging system 22 is responsible for projecting the image of the display screen 21 to the coupling region 110 of the one-dimensional optical waveguide 10, and then transmitting the image to the human eye through the one-dimensional optical waveguide 10. In this process, Figure 2At the same time, the reflective propagation mode of the light emitted from the display screen 21 is shown. It can be understood that since the reflective imaging system 22 projects the image into the human eye in a reflective manner, the reflective imaging system 22 can shorten the distance between the display screen 21 and the human eye in the direction of the optical axis compared to the direct transmission imaging system. In other words, it can also be understood that the structure of the imaging system can be reduced, shortening the distance between the display screen 21 and the one-dimensional optical waveguide 10. Specifically, a first returning surface 221 and a second returning surface 222 may be provided in the returning imaging system 22 for realizing the returning of light, wherein the first returning surface 221 may allow the light projected from the display screen 21 to the corresponding position of the first returning surface 221 to be transmitted, and the second returning surface 222 may allow the light projected from the first returning surface 221 to the corresponding area of ​​the second returning surface 222 to be reflected, and at the same time, the first returning surface 221 may also allow the light reflected from the second returning surface 222 to the first returning surface 221 to continue to be reflected, and the second returning surface 222 may also allow the light reflected from the first returning surface 221 to the second returning surface 222 to be transmitted and enter the one-dimensional optical waveguide 10.

[0102] Optionally, in the embodiment of the present invention, the reentrant imaging system 22 has a positive optical power. It can be understood that in order to ensure the overall display of the picture, the display screen 21 needs to be arranged on the optical axis, such as Figure 2 As shown, the reflection process of the outgoing light of the reflection imaging system 22 with positive optical focal length in the reflection imaging system 22 is essentially a process of light diffusion and then convergence. Therefore, it can be seen that the light reflection process of the reflection imaging system 22 is also a process of increasing the field of view angle and the pupil.

[0103] The above technical solution is provided in a near-eye display module, wherein the one-dimensional optical waveguide includes a coupling-in area and a coupling-out area, and the coupling-in area and the coupling-out area are arranged in a first direction, and the first direction is the pupil expansion direction of the one-dimensional optical waveguide; the optical machine is arranged toward the coupling-in area of ​​the one-dimensional optical waveguide; the optical machine includes a display screen and a reentrant imaging system, the reentrant imaging system is located on the light emitting side of the display screen, and the display screen is located on the object focal plane of the reentrant imaging system; the reentrant imaging system includes a first reentrant surface and a second reentrant surface arranged along the optical axis, and at least part of the light emitted from any position on the display screen is sequentially transmitted to the second reentrant surface through the first reentrant surface, reflected to the first reentrant surface through the second reentrant surface, reflected to the second reentrant surface through the first reentrant surface, and transmitted to the coupling-in area of ​​the one-dimensional optical waveguide through the second reentrant surface. The embodiments of the present invention solve the problem that the one-dimensional optical waveguide coupled optical machine is incompatible with the advantages of small size, large field of view angle, small aberration, large pupil, etc., and has the problems of being bulky and having a small field of view angle. The light reflection is achieved through a reflection imaging system, which reduces the distance between the display screen and the one-dimensional optical waveguide, reduces the size and weight of the optical machine, and at the same time increases the field of view angle, increases the pupil, reduces the user's eye fatigue, and effectively improves the user's experience during actual use.

[0104] Specifically, the embodiment of the present invention provides two specific implementations for the specific implementation of the reentry imaging system, one is a Cassegrain reentry system, and the other is a polarization reentry system. The specific structures and implementation principles of the two reentry imaging systems are introduced below.

[0105] Figure 3 is a schematic diagram of the structure of another near-eye display module in the YOZ plane provided by an embodiment of the present invention, with reference to Figure 1 and Figure 3 In one embodiment, the reflection imaging system 22 includes a lens subsystem 2200, the lens subsystem 2200 includes at least a first lens 2201, a first reflection surface 221 is located on the object side surface of the first lens 2201, and a second reflection surface 222 is located on the image side surface of the first lens 2201; the first reflection surface 221 includes a first transmission area 2211 and a first reflection area 2212, and the first reflection area 2212 surrounds the first transmission area 2211; the second reflection surface 222 includes a second transmission area 2221 and a second reflection area 2222, and the second transmission area 2221 surrounds the second reflection area 2222.

[0106] Along the optical axis direction, the projection of the display screen 21 is located in the projection of the first transmission area 2211, and the projection of the first transmission area 2211 is located in the projection of the second reflection area 2222; at least part of the light emitted from any position on the display screen 21 is sequentially transmitted through the first transmission area 2211 to the second reflection area 2222, reflected from the second reflection area 2222 to the first reflection area 2212, reflected from the first reflection area 2212 to the second transmission area 2221, and transmitted to the coupling-in area 110 of the one-dimensional optical waveguide 10 through the second transmission area 2221.

[0107] The reflection imaging system 22 in this embodiment is essentially a Cassegrain reflection structure, in which the lens subsystem 2200 is mainly responsible for converging the light for imaging, and at the same time, corresponding transmission areas and reflection areas are set on the lens in the lens subsystem 2200 to control the transmission or reflection process of the lens surface to the light. Among them, there is a first lens 2201 in the optional lens subsystem 2200, and the transmission area and the reflection area are respectively set on the object side surface and the image side surface of the first lens 2201. Of course, in other embodiments of the present invention, the lens subsystem 2200 can also be selected to include more than one lens, so that the first reflection surface 221 and the second reflection surface 222 that form the reflection can be located on the front and back surfaces of the same lens, or can be set on two surfaces of different lenses.

[0108] Specifically, optionally, the first transmission area 2211 of the object side surface of the first lens 2201 is provided with a first transmission film, and the first reflection area 2212 is provided with a first reflection film; the second transmission area 2221 of the image side surface of the first lens 2201 is provided with a second transmission film, and the second reflection area 2222 is provided with a second reflection film. The transmission film refers to an anti-reflection film or an anti-reflection film, which can increase the transmittance of light on the surface. The reflection film can be a metal film, etc., which can avoid the transmission of light and increase the reflectivity.

[0109] In order to ensure effective reflection so that the image displayed on the display screen 21 can effectively enter the human eye, this embodiment also provides a regional range setting scheme for the transmission area and the reflection area on the two reflection surfaces. For a clear understanding, here, according to the projection area of ​​the outgoing light beam at a special position point on the display screen 21 when it is reflected on the two reflection surfaces in theory, it is used as a reference and comparison standard to define the sizes of the two transmission areas and the two reflection areas accordingly. The theoretical definition standard here is that the light is transmitted when it is projected on the first reflection surface 221 for the first time, reflected when it is projected on the second reflection surface 222 for the first time, reflected when it is projected on the first reflection surface 221 for the second time, and transmitted when it is projected on the second reflection surface 222 for the second time. First of all, the light beams emitted from different positions on the display screen 21 all have fixed emission angles. In other words, it can be understood that the light beams emitted from different positions on the display screen 21 according to the cone will form corresponding projection areas during the reflection process on the first reflection surface 221 and the second reflection surface 222. Furthermore, based on a fixed light beam emission angle, a fixed distance between each surface, and the refractive index of each structure in space, the regional position and area of ​​the light beam when projected onto different surfaces can be known. Figure 4 and Figure 5 is a schematic diagram of the beam return projection area on two planes provided by an embodiment of the present invention, and the following reference Figure 4 and Figure 5 , taking the projection area of ​​the edge point on the display screen 21 on the two reentrant surfaces as the edge projection area, the projection areas of each position point twice on the two reentrant surfaces are named as follows:

[0110] The projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the first plane YOZ on the first returning surface 221 is the first edge projection area 311;

[0111] The second projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the first plane YOZ on the first returning surface 221 is the second edge projection area 312;

[0112] The projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the first plane YOZ on the second returning surface 222 is the third edge projection area 313;

[0113] The second projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the first plane YOZ on the second returning surface 222 is the fourth edge projection area 314;

[0114] The projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the second plane XOZ on the first reflecting surface 221 is the fifth edge projection area 315;

[0115] The second projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the second plane XOZ on the first returning surface 221 is the sixth edge projection area 316;

[0116] The projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the second plane XOZ on the second reflecting surface 222 for the first time is the seventh edge projection area 317;

[0117] The second projection area of ​​the outgoing light beam of the display screen 21 at the edge point of the second plane XOZ on the first returning surface 221 is the eighth edge projection area 318 .

[0118] The projection area of ​​the center point on the display screen 21 on the two refraction surfaces is taken as the center projection area, and the projection areas of each position point twice on the two refraction surfaces are named as follows:

[0119] The projection area of ​​the outgoing light beam of the display screen 21 at the center point of the first plane YOZ on the first returning surface 221 is the first central projection area 321;

[0120] The second projection area of ​​the light beam emitted from the display screen 21 at the center point of the first plane YOZ on the first returning surface 221 is the second center projection area 322;

[0121] The projection area of ​​the outgoing light beam of the display screen 21 at the center point of the first plane YOZ on the second reflecting surface 222 is the third center projection area 323;

[0122] The second projection area of ​​the outgoing light beam of the display screen 21 at the center point of the first plane YOZ on the second returning surface 222 is the fourth central projection area 324;

[0123] The projection area of ​​the outgoing light beam of the display screen 21 at the center point of the second plane XOZ on the first reflecting surface 221 is the fifth central projection area 325;

[0124] The projection area of ​​the outgoing light beam of the display screen 21 at the center point of the second plane XOZ on the first reflecting surface 221 for the second time is the sixth central projection area 326;

[0125] The projection area of ​​the outgoing light beam of the display screen 21 at the center point of the second plane XOZ on the second reflecting surface 222 for the first time is the seventh center projection area 327;

[0126] The second projection area of ​​the light beam emitted from the display screen 21 at the center point of the second plane XOZ on the second reflecting surface 222 is the eighth central projection area 328 .

[0127] Specifically, the reflection imaging system 22 includes a first plane YOZ and a second plane XOZ, the first plane YOZ and the second plane XOZ are perpendicular to each other and intersect at the optical axis of the reflection imaging system 22; the first transmission area 2211, the first reflection area 2212, the second transmission area 2221 and the second reflection area 2222 are all symmetrical relative to the first plane YOZ, and are all symmetrical relative to the second plane XOZ.

[0128] Based on this, the sizes of the two transmission areas and the two reflection areas are defined as follows:

[0129] h>A; H21c1<H / 2<H21a2;

[0130] Among them, A is the length of the intersection line between the display screen 21 and the first plane YOZ; h is the length of the intersection line between the first transmission area 2211 and the first plane YOZ, H is the length of the intersection line between the second reflection area 2222 and the first plane YOZ; H21c1 is the distance between the point closest to the optical axis in the third edge projection area 313 in the first plane YOZ and the optical axis, and H21a2 is the distance between the point farthest from the optical axis in the fourth edge projection area 314 in the first plane YOZ and the optical axis.

[0131] Figure 6-Figure 8 Schematic diagram of three foldback size designs of near-eye display modules provided by embodiments of the present invention, with reference to Figure 6 According to the definition of each projection area, in the first plane YOZ, it can be understood that when h>A, it means that the length of the first transmission area 2211 is greater than the length of the display screen 21, thereby ensuring that the light emitted from the display screen 21 can be fully transmitted when it is first projected to the first returning surface 221; and setting H21c1<H / 2<H21a2, that is, taking the position of the optical axis as the origin, the height of the boundary point of the second reflection area 2222 is between H21c1 and H21a2, thereby ensuring that at least part of the light emitted from the edge point of the display screen 21 can be reflected when it reaches the second returning surface 222 for the first time, and transmitted when it reaches the second returning surface for the second time.

[0132] v>B; V21f1<V / 2<V21d2, and D<V<D0; wherein, B is the length of the intersection line between the display screen and the second plane; v is the length of the intersection line between the first transmission area and the second plane, and V is the length of the intersection line between the second reflection area and the second plane; V21f1 is the distance between the point of the seventh edge projection area 317 in the second plane XOZ that is closest to the optical axis and the optical axis, and V21d2 is the distance between the point of the eighth edge projection area 318 in the second plane XOZ that is farthest from the optical axis and the optical axis; D is the diameter of the field of view formed by the outgoing light beam from the edge point farthest from the center point on the display screen through the lens subsystem on the image side focal plane; D0 is the diameter of the field of view formed by the outgoing light beam from the center point on the display screen through the lens subsystem on the image side focal plane.

[0133] refer to Figure 7 Similarly, according to the definition of each projection area, in the second plane XOZ, it can be understood that when v>B, it means that the length of the first transmission area 2211 is also greater than the length of the display screen 21, thereby ensuring that the light emitted from the display screen 21 can be fully transmitted when it is first projected to the first reflecting surface 221; and setting V21f1<V / 2<V21d2 also means that the height of the boundary point of the second reflection area 2222 is between V21f1 and V21d2 with the position of the optical axis as the origin, thereby ensuring that at least part of the light emitted from the edge point of the display screen 21 can be reflected when it reaches the second reflecting surface 222 for the first time, and transmitted when it reaches the second reflecting surface for the second time; refer to Figure 8 In addition, setting D<V<D0 ensures that the size of the second reflection area 2222 is larger than the field of view formed by the outgoing light beam from the edge point farthest from the center point on the display screen through the lens subsystem on the image side focal plane, and smaller than the diameter of the field of view formed by the outgoing light beam from the center point on the display screen through the lens subsystem on the image side focal plane. This ensures that the second reflection area 2222 will not completely block the light beams at these two positions, thereby ensuring that the image of the display screen 21 is completely imaged in the human eye.

[0134] Specifically, 2mm<D<8mm, 2mm<D0<8mm can be set. Among them, although the pupil size of the human eye will change due to the influence of the ambient light intensity, it is basically within 2-8mm. By setting the above size range to be not less than 2mm and not more than 8mm, the actual pupil size of the human eye can be adapted to ensure that the human eye can receive the outgoing light of the display screen 21, so that the image is formed in the human eye.

[0135] Further, H21c1<H / 2<H21c2, and h22c1<h / 2<h22c2; wherein, H21c1 is the distance between the point of the third edge projection area 313 in the first plane YOZ that is closest to the optical axis and the optical axis, H21c2 is the distance between the point of the fourth edge projection area 314 in the first plane YOZ that is closest to the optical axis and the optical axis, h22c1 is the distance between the point of the first edge projection area 311 in the first plane YOZ that is closest to the optical axis and the optical axis, and h22c2 is the distance between the point of the second edge projection area 312 in the first plane YOZ that is closest to the optical axis and the optical axis.

[0136] Figure 9-13 Schematic diagram of five folded size designs of near-eye display modules provided by embodiments of the present invention, with reference to Fig. 9 According to the definition of each projection area, in the first plane YOZ, it can be understood that setting H21c1<H / 2<H21c2 means that the height of the boundary point of the second reflection area 2222 is between H21c1 and H21c2 with the position of the optical axis as the origin, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light close to the optical axis can be reflected when it reaches the second returning surface 222 for the first time and transmitted when it reaches the second returning surface 222 for the second time; at the same time, setting h22c1<h / 2<h22c2, That is to say, with the position of the optical axis as the origin, the height of the boundary point of the first transmission area 2211 is between h22c1 and h22c2, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light close to the optical axis can be transmitted when it reaches the first returning surface 221 for the first time, and reflected when it reaches the first returning surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be reflected, thereby entering the human eye for imaging.

[0137] Alternatively, H21a1<H / 2<H21a2, h22a1<h / 2<h22a2; wherein, H21a1 is the distance between the point of the third edge projection area 313 in the first plane YOZ that is closest to the optical axis and the optical axis, and H21a2 is the distance between the point of the fourth edge projection area 314 in the first plane YOZ that is farthest from the optical axis and the optical axis; h22a1 is the distance between the point of the first edge projection area 311 in the first plane YOZ that is farthest from the optical axis and the optical axis; h22a2 is the distance between the point of the second edge projection area 312 in the first plane YOZ that is farthest from the optical axis and the optical axis.

[0138] refer to Fig.10According to the definition of each projection area, in the first plane YOZ, it can be understood that setting H21a1<H / 2<H21a2 means that the height of the boundary point of the second reflection area 2222 is between H21a1 and H21a2 with the position of the optical axis as the origin, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light far from the optical axis can be reflected when it reaches the second returning surface 222 for the first time and transmitted when it reaches the second returning surface 222 for the second time; at the same time, setting h22a1<h / 2<h22a2, That is to say, with the position of the optical axis as the origin, the height of the boundary point of the first transmission area 2211 is between h22a1 and h22a2, thereby ensuring that the light in the light beam emitted from the edge point of the display screen 21, which is far from the optical axis, can be transmitted when it reaches the first returning surface 221 for the first time, and reflected when it reaches the first returning surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light in the light beam emitted from the edge point of the display screen 21, which is far from the optical axis, can be reflected, and thus enter the human eye for imaging.

[0139] Further, V21f1<V / 2<V21f2, and v22f1<v / 2<v22f2; wherein V21f1 is the distance between the point of the seventh edge projection area 317 in the second plane XOZ that is closest to the optical axis and the optical axis; V21f2 is the distance between the point of the eighth edge projection area 318 in the second plane XOZ that is closest to the optical axis and the optical axis; v22f1 is the distance between the point of the fifth edge projection area 315 in the second plane XOZ that is closest to the optical axis and the optical axis; v22f2 is the distance between the point of the sixth edge projection area 316 in the second plane XOZ that is closest to the optical axis and the optical axis.

[0140] refer to Fig.11 According to the definition of each projection area, in the second plane XOZ, it can be understood that setting V21f1<V / 2<V21f2 means that the height of the boundary point of the second reflection area 2222 is between V21f1 and V21f2 with the position of the optical axis as the origin, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light close to the optical axis can be reflected when it reaches the second returning surface 222 for the first time and transmitted when it reaches the second returning surface 222 for the second time; at the same time, setting v22f1<v / 2<v22f2, That is to say, with the position of the optical axis as the origin, the height of the boundary point of the first transmission area 2211 is between v22f1 and v22f2, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light close to the optical axis can be transmitted when it reaches the first returning surface 221 for the first time, and reflected when it reaches the first returning surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be reflected, thereby entering the human eye for imaging.

[0141] Alternatively, V21d1<V / 2<V21d2, and v22d1<v / 2<v22d2; wherein V21d1 is the distance between the point farthest from the optical axis in the seventh edge projection area 317 in the second plane XOZ and the optical axis; V21d2 is the distance between the point farthest from the optical axis in the eighth edge projection area 318 in the second plane XOZ and the optical axis; v22d1 is the distance between the point farthest from the optical axis in the fifth edge projection area 315 in the second plane XOZ and the optical axis; v22d2 is the distance between the point farthest from the optical axis in the sixth edge projection area 316 in the second plane XOZ and the optical axis.

[0142] refer to Fig.12 According to the definition of each projection area, in the second plane XOZ, it can be understood that setting V21d1<V / 2<V21d2 means that the height of the boundary point of the second reflection area 2222 is between V21d1 and V21d2 with the position of the optical axis as the origin, thereby ensuring that in the light beam emitted from the edge point of the display screen 21, the light far from the optical axis can be reflected when it reaches the second returning surface 222 for the first time and transmitted when it reaches the second returning surface 222 for the second time; at the same time, setting v22d1<v / 2<v22d2, That is to say, with the position of the optical axis as the origin, the height of the boundary point of the first transmission area 2211 is between v22d1 and v22d2, thereby ensuring that the light in the light beam emitted from the edge point of the display screen 21, which is far from the optical axis, can be transmitted when it reaches the first returning surface 221 for the first time, and reflected when it reaches the first returning surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light in the light beam emitted from the edge point of the display screen 21, which is far from the optical axis, can be reflected, and thus enter the human eye for imaging.

[0143] Moreover, V11d1<V / 2<V11d2, and v12d1<v / 2<v12d2; wherein, V11d1 is the distance between the point farthest from the optical axis and the optical axis in the seventh central projection area 327 in the second plane XOZ; V11d2 is the distance between the point farthest from the optical axis and the optical axis in the eighth central projection area 328 in the second plane XOZ; v12d1 is the distance between the point farthest from the optical axis and the optical axis in the fifth central projection area 325 in the second plane XOZ; v12d2 is the distance between the point farthest from the optical axis and the optical axis in the second plane XOZ.

[0144] refer to Fig.13According to the definition of each projection area, in the second plane XOZ, it can be understood that setting V11d1<V / 2<V11d2 means that the height of the boundary point of the second reflection area 2222 is between V11d1 and V11d2 with the position of the optical axis as the origin, thereby ensuring that in the light beam emitted from the center point of the display screen 21, the light far from the optical axis can be reflected when it reaches the second returning surface 222 for the first time and transmitted when it reaches the second returning surface 222 for the second time; at the same time, setting v12d1<v / 2<v12d2, That is to say, with the position of the optical axis as the origin, the height of the boundary point of the first transmission area 2211 is between v12d1 and v12d2, thereby ensuring that the light in the light beam emitted from the center point of the display screen 21, which is far from the optical axis, can be transmitted when it reaches the first returning surface 221 for the first time, and reflected when it reaches the first returning surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light in the light beam emitted from the center point of the display screen 21, which is far from the optical axis, can be reflected, and thus enter the human eye for imaging.

[0145] In summary, through the size range limitation of the second reflective area 2222 and the first transmission area 2211, it can be ensured that at least part of the light in the light beam emitted from the edge point of the display screen 21 is folded back in the two dimensions of the first plane YOZ and the second plane XOZ, so as to be incident on the human eye for imaging. At the same time, it can also be ensured that at least part of the light in the light beam emitted from the center point of the display screen 21 is also folded back in the dimension of the second plane XOZ, so as to be incident on the human eye for imaging. In other words, in this embodiment, by differentially setting the sizes of the second reflective area 2222 and the first transmission area 2211 in the dimensions of the first plane YOZ and the second plane XOZ, the sizes of the two areas in the dimension of the second plane XOZ are controlled to be smaller than the sizes in the dimension of the first plane YOZ, so that the center point of the display screen 21 can be folded back in the dimension of the second plane XOZ and projected into the human eye, thereby avoiding the problem that the second reflective area 2222 on the second folding surface 222 in the folding structure blocks the light, resulting in the central area of ​​the display screen 21 being unable to be imaged into the human eye.

[0146] Further optionally, in the embodiment of the present invention, the projection shapes of the first transmission area 2211 and the second reflection area 2222 along the optical axis direction may be the same, and both may be rectangular, elliptical or irregular polygonal. In which, taking a rectangle as an example, the long side direction of the first transmission area 2211 and the second reflection area 2222 is the Y-axis direction, and the short side direction is the X-axis direction; taking an ellipse as an example, the long side direction of the first transmission area 2211 and the second reflection area 2222 is the Y-axis direction, and the short side direction is the X-axis direction.

[0147] Fig.14is another schematic diagram of an equivalent structure of a near-eye display module in the YOZ plane provided by an embodiment of the present invention, with reference to Fig.14 , in another embodiment, the folded imaging system 22 includes a transmissive polarizer 2202, a first quarter wave plate 2203, a lens subsystem 2200, a second quarter wave plate 2204 and a reflective polarizer 2205 which are sequentially arranged along the optical axis;

[0148] The lens subsystem 2200 includes at least a first lens 2201, and the first folding surface 221 is located on the object side surface of the first lens 2201; the first folding surface 221 includes a first transmission area 2211 and a first reflection area 2212, and the first reflection area 2212 surrounds the first transmission area 2211; the second folding surface 222 is located on the reflective polarizer 2205; along the optical axis direction, the projection of the display screen 21 is located in the projection of the first transmission area 2211.

[0149] At least part of the light emitted from any position on the display screen 21 is transmitted through the transmission polarizer 2202 in sequence to form horizontally polarized light P, transmitted through the first quarter-wave plate 2203 to form right-handed circularly polarized light R-CPL, transmitted through the first transmission area 2211, transmitted through the second quarter-wave plate 2204 to form horizontally polarized light P, reflected through the reflective polarizer 2205, transmitted through the second quarter-wave plate 2204 to form right-handed circularly polarized light R-CPL, reflected through the first reflection area 2212 to form left-handed circularly polarized light L-CPL, transmitted through the second quarter-wave plate 2204 to form vertically polarized light S, and transmitted through the reflective polarizer 2205 to the coupling-in area 110 of the one-dimensional optical waveguide 10.

[0150] The reflection imaging system 22 in this embodiment is essentially a polarization reflection structure, and the lens subsystem 2200 is also mainly responsible for converging the light for imaging. At the same time, corresponding transmission areas and reflection areas are set on the lens in the lens subsystem 2200, and the polarization and analysis structures are used to control the transmission or reflection process of the lens surface to the light. Among them, there is a first lens 2201 in the optional lens subsystem 2200, and a transmission area and a reflection area are set on the object side surface of the first lens 2201. Of course, in other embodiments of the present invention, the lens subsystem 2200 can also be selected to include more than one lens, so that the first reflection surface 221 forming the reflection can be located on the surface of any lens.

[0151] Specifically, optionally, the first transmission area 2211 of the object side surface of the first lens 2201 is provided with a first transmission film, and the first reflection area 2212 is provided with a first reflection film. The transmission film refers to an anti-reflection film or an anti-reflection film, which can increase the transmittance of light on the surface. The reflection film can be a metal film, etc., which can avoid the transmission of light and increase the reflectivity.

[0152] Similarly, to ensure effective folding so that the image displayed on the display screen 21 can effectively enter the human eye, this embodiment also provides an area range setting scheme for the transmission area and the reflection area on the first folding surface. The corresponding naming rules refer to the previous embodiment and will not be repeated here.

[0153] Specifically, the reflection imaging system 22 includes a first plane YOZ and a second plane XOZ, the first plane YOZ and the second plane XOZ are perpendicular to each other and intersect at the optical axis of the reflection imaging system 22; the first transmission area 2211 and the first reflection area 2212 are both symmetrical relative to the first plane YOZ, and are both symmetrical relative to the second plane XOZ.

[0154] It should be noted that, since the present embodiment adopts the polarization reflection principle, parallel polarized light is reflected and vertical polarized light is transmitted on the second reflection surface 222, i.e., the reflective polarizer 2205, instead of the reflection film and the transmission film being used for reflection and transmission, the light incident on the second reflection surface 222 will not be blocked. Therefore, whether the light is reflected or not mainly depends on the size setting of the transmission area and the reflection area on the first reflection surface 221.

[0155] Based on this, the sizes of the transmission area and the reflection area on the first folding surface are defined as follows:

[0156] h>A; v>B; wherein h is the length of the intersection line between the first transmission area and the first plane; A is the length of the intersection line between the display screen and the first plane; v is the length of the intersection line between the first transmission area and the second plane; B is the length of the intersection line between the display screen and the second plane.

[0157] Continue to refer Fig.14 , in the first plane YOZ, it can be understood that when h>A, it means that the length of the first transmission area 2211 is greater than the length of the display screen 21, thereby ensuring that the outgoing light on the display screen 21 can be completely transmitted when it is first projected to the first returning surface 221; similarly, in the second plane XOZ, it can be understood that when v>B, it means that the length of the first transmission area 2211 is greater than the length of the display screen 21, thereby ensuring that the outgoing light on the display screen 21 can be completely transmitted when it is first projected to the first returning surface 221.

[0158] Further, h22c1<h / 2<h22c2; wherein, v22c1 is the distance between the point of the first edge projection area 311 closest to the optical axis in the first plane YOZ and the optical axis; h22c2 is the distance between the point of the second edge projection area 312 closest to the optical axis in the first plane YOZ and the optical axis.

[0159] Figure 15-Figure 20 Schematic diagram of six foldback size designs of near-eye display modules provided by embodiments of the present invention, with reference to Fig.15According to the definition of each projection area, in the first plane YOZ, it can be understood that setting h22c1<h / 2<h22c2 means that the height of the boundary point of the first transmission area 2211 is between h22c1 and h22c2 with the position of the optical axis as the origin, thereby ensuring that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be transmitted when it reaches the first turning surface 221 for the first time, and reflected when it reaches the first turning surface 221 for the second time; therefore, the size range of the first transmission area 2211 ensures that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be turned back, thereby entering the human eye for imaging.

[0160] Alternatively, h22a1<h / 2<h22a2; wherein h22a1 is the distance between the point farthest from the optical axis in the first edge projection area 311 in the first plane YOZ and the optical axis; h22a2 is the distance between the point farthest from the optical axis in the second edge projection area 312 in the first plane YOZ and the optical axis.

[0161] refer to Fig.16 According to the definition of each projection area, in the first plane YOZ, it can be understood that setting h22a1<h / 2<h22a2 means that the height of the boundary point of the first transmission area 2211 is between h22a1 and h22a2 with the position of the optical axis as the origin, thereby ensuring that the light rays in the light beam emitted from the edge point of the display screen 21, which are far from the optical axis, can be transmitted when they reach the first reflecting surface 221 for the first time, and reflected when they reach the first reflecting surface 221 for the second time; therefore, the size range of the first transmission area 2211 ensures that the light rays in the light beam emitted from the edge point of the display screen 21, which are far from the optical axis, can be reflected, and thus enter the human eye for imaging.

[0162] Moreover, h12a1<h / 2<h12a2; wherein, h12a1 is the distance between the point farthest from the optical axis in the first central projection area 321 in the first plane YOZ and the optical axis; h12a2 is the distance between the point farthest from the optical axis in the second central projection area 322 in the first plane YOZ and the optical axis.

[0163] refer to Fig.17According to the definition of each projection area, in the first plane YOZ, it can be understood that setting h12a1<h / 2<h12a2 means that the height of the boundary point of the first transmission area 2211 is between h12a1 and h12a2 with the position of the optical axis as the origin, thereby ensuring that the light beam emitted from the center point of the display screen 21, which is far from the optical axis, can be transmitted when it reaches the first reflecting surface 221 for the first time, and reflected when it reaches the first reflecting surface 221 for the second time; therefore, the size range of the second reflection area 2222 and the first transmission area 2211 ensures that the light beam emitted from the edge point of the display screen 21, which is far from the optical axis, can be reflected, thereby entering the human eye for imaging.

[0164] Similarly, v22f1<v / 2<v22f2; wherein v22f1 is the distance between the point of the fifth edge projection area 315 closest to the optical axis in the second plane XOZ and the optical axis; v22f2 is the distance between the point of the sixth edge projection area 316 closest to the optical axis in the second plane XOZ and the optical axis.

[0165] refer to Fig.18 According to the definition of each projection area, in the second plane XOZ, it can be understood that setting v22f1<v / 2<v22f2 means that the height of the boundary point of the first transmission area 2211 is between v22f1 and v22f2 with the position of the optical axis as the origin, thereby ensuring that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be transmitted when it reaches the first turning surface 221 for the first time, and reflected when it reaches the first turning surface 221 for the second time; therefore, the size range of the first transmission area 2211 ensures that the light close to the optical axis in the light beam emitted from the edge point of the display screen 21 can be turned back, thereby entering the human eye for imaging.

[0166] Alternatively, v22d1<v / 2<v22d2; wherein v22d1 is the distance between the point farthest from the optical axis in the fifth edge projection area 315 in the second plane XOZ and the optical axis; v22d2 is the distance between the point farthest from the optical axis in the sixth edge projection area 316 in the second plane XOZ and the optical axis.

[0167] refer to Fig.19According to the definition of each projection area, in the second plane XOZ, it can be understood that setting v22d1<v / 2<v22d2 means that the height of the boundary point of the first transmission area 2211 is between v22d1 and v22d2 with the position of the optical axis as the origin, thereby ensuring that the light rays in the light beam emitted from the edge point of the display screen 21, which are far from the optical axis, can be transmitted when they reach the first reflecting surface 221 for the first time, and reflected when they reach the first reflecting surface 221 for the second time; therefore, the size range of the first transmission area 2211 ensures that the light rays in the light beam emitted from the edge point of the display screen 21, which are far from the optical axis, can be reflected, and thus enter the human eye for imaging.

[0168] Moreover, v12d1<v / 2<v12d2; wherein, v12d1 is the distance between the point farthest from the optical axis in the fifth central projection area 325 in the second plane XOZ and the optical axis; v12d2 is the distance between the point farthest from the optical axis in the eighth central projection area 328 in the second plane XOZ and the optical axis.

[0169] refer to Fig. 20 According to the definition of each projection area, in the second plane XOZ, it can be understood that setting v12d1<v / 2<v12d2 means that the height of the boundary point of the first transmission area 2211 is between v12d1 and v12d2 with the position of the optical axis as the origin, thereby ensuring that the light rays far from the optical axis in the light beam emitted from the center point of the display screen 21 can be transmitted when it reaches the first reflecting surface 221 for the first time, and reflected when it reaches the first reflecting surface 221 for the second time; therefore, the size range of the first transmission area 2211 ensures that the light rays far from the optical axis in the light beam emitted from the center point of the display screen 21 can be reflected, thereby entering the human eye for imaging.

[0170] Alternatively, in the above embodiments, the first lens 2201 in the lens subsystem 2200 may be a meniscus lens convex toward the display screen. The meniscus lens with positive focal length can meet the requirements of converging the light emitted from the display screen 21 and completing the internal folding.

[0171] Alternatively, in each of the above embodiments, the object side surface or the image side surface of the first lens 2201 in the lens subsystem 2200 may be set to be a spherical surface, an aspherical surface, a free-form surface, or a diffractive surface. By setting the specific surface morphology of the first lens 2201, various aberrations that are easily generated by the lens, such as distortion, field curvature, chromatic aberration, etc., can be corrected through the spherical surface, the aspherical surface, the free-form surface, or the diffractive surface, so as to ensure the imaging quality of the near-eye display module and avoid distortion of the displayed image.

[0172] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection 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, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A near-eye display module, characterized in that: include: A one-dimensional optical waveguide, the one-dimensional optical waveguide comprising an incoupling region and an outcoupling region, the incoupling region and the outcoupling region are arranged in a first direction, and the first direction is a pupil expansion direction of the one-dimensional optical waveguide; An optical machine is arranged toward the coupling-in region of the one-dimensional optical waveguide; the optical machine comprises a display screen and a reentrant imaging system, the reentrant imaging system is located at the light-emitting side of the display screen, and the display screen is located on the object focal plane of the reentrant imaging system; The refraction imaging system comprises a first refraction surface and a second refraction surface arranged along the optical axis, and at least part of the light emitted from any position on the display screen is sequentially transmitted through the first refraction surface to the second refraction surface, reflected through the second refraction surface to the first refraction surface, reflected through the first refraction surface to the second refraction surface, and transmitted through the second refraction surface to the coupling-in region of the one-dimensional optical waveguide.

2. The near-eye display module according to claim 1, characterized in that: The folding imaging system comprises a lens subsystem, wherein the lens subsystem comprises at least a first lens, wherein the first folding surface is located on the object side surface of the first lens, and the second folding surface is located on the image side surface of the first lens; The first folding surface includes a first transmission area and a first reflection area, and the first reflection area surrounds the first transmission area; the second folding surface includes a second transmission area and a second reflection area, and the second transmission area surrounds the second reflection area; Along the optical axis direction, the projection of the display screen is located in the projection of the first transmission area, and the projection of the first transmission area is located in the projection of the second reflection area; At least part of the light emitted from any position on the display screen is sequentially transmitted through the first transmission area to the second reflection area, reflected through the second reflection area to the first reflection area, reflected through the first reflection area to the second transmission area, and transmitted through the second transmission area to the coupling-in area of ​​the one-dimensional optical waveguide.

3. The near-eye display module according to claim 2, characterized in that: The first transmission area of ​​the object side surface of the first lens is provided with a first transmission film, and the first reflection area is provided with a first reflection film; The second transmission area of ​​the image-side surface of the first lens is provided with a second transmission film, and the second reflection area is provided with a second reflection film.

4. The near-eye display module according to claim 2, characterized in that: The reentry imaging system comprises a first plane and a second plane, wherein the first plane and the second plane are perpendicular to each other and intersect at the optical axis of the reentry imaging system; The first transmission area, the first reflection area, the second transmission area and the second reflection area are all self-symmetrical relative to the first plane, and are all self-symmetrical relative to the second plane; wherein: h>A; H21c1<H / 2<H21a2; Wherein, A is the length of the intersection line between the display screen and the first plane; h is the length of the intersection line between the first transmission area and the first plane, and H is the length of the intersection line between the second reflection area and the first plane; H21c1 is the distance between the point of the third edge projection area in the first plane that is closest to the optical axis and the optical axis, and the third edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface for the first time; H21a2 is the distance between the point of the fourth edge projection area in the first plane that is farthest from the optical axis and the optical axis; the fourth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface; v>B;V21f1<V / 2<V21d2,and D<V<D0; Wherein, B is the length of the intersection line between the display screen and the second plane; v is the length of the intersection line between the first transmission area and the second plane, and V is the length of the intersection line between the second reflection area and the second plane; V21f1 is the distance between the point of the seventh edge projection area in the second plane that is closest to the optical axis and the optical axis, and the seventh edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time; V21d2 is the distance between the point of the eighth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the eighth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface; D is the diameter of the field of view formed by the outgoing light beam from the edge point on the display screen farthest from the center point through the lens subsystem on the image side focal plane; D0 is the diameter of the field of view formed by the outgoing light beam from the center point on the display screen through the lens subsystem on the image side focal plane.

5. The near-eye display module according to claim 4, characterized in that: H21c1<H / 2<H21c2, and h22c1<h / 2<h22c2; or, H21a1<H / 2<H21a2, h22a1<h / 2<h22a2; H21c1 is the distance between the point of the third edge projection area in the first plane that is closest to the optical axis and the optical axis, and the third edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface for the first time; H21c2 is the distance between the point of the fourth edge projection area in the first plane that is closest to the optical axis and the optical axis, and the fourth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the second returning surface; h22c1 is the distance between the point of the first edge projection area in the first plane that is closest to the optical axis and the optical axis, and the first edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the first returning surface for the first time; h22c2 is the distance between the point of the second edge projection area in the first plane that is closest to the optical axis and the optical axis, and the second edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the first plane on the first returning surface for the second time; H21a1 is the distance between the point closest to the optical axis in the third edge projection area in the first plane and the optical axis; H21a2 is the distance between the point farthest from the optical axis in the fourth edge projection area in the first plane and the optical axis; h22a1 is the distance between the point farthest from the optical axis in the first edge projection area in the first plane and the optical axis; h22a2 is the distance between the point farthest from the optical axis in the second edge projection area in the first plane and the optical axis.

6. The near-eye display module according to claim 4, characterized in that: V21f1<V / 2<V21f2, and v22f1<v / 2<v22f2; or, V21d1<V / 2<V21d2, and v22d1<v / 2<v22d2; V21f1 is the distance between the point of the seventh edge projection area in the second plane that is closest to the optical axis and the optical axis; the seventh edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time; V21f2 is the distance between the point of the eighth edge projection area in the second plane that is closest to the optical axis and the optical axis; the eighth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface for the first time; v22f1 is the distance between the point of the fifth edge projection area in the second plane that is closest to the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time; v22f2 is the distance between the point of the sixth edge projection area in the second plane that is closest to the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface; V21d1 is the distance between the point farthest from the optical axis in the seventh edge projection area in the second plane and the optical axis; V21d2 is the distance between the point farthest from the optical axis in the eighth edge projection area in the second plane and the optical axis; v22d1 is the distance between the point farthest from the optical axis in the fifth edge projection area in the second plane and the optical axis; v22d2 is the distance between the point farthest from the optical axis in the sixth edge projection area in the second plane and the optical axis; V11d1<V / 2<V11d2, and v12d1<v / 2<v12d2; V11d1 is the distance between the point of the seventh central projection area in the second plane that is farthest from the optical axis and the optical axis; the seventh central projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second reflecting surface for the first time; V11d2 is the distance between the point of the eighth central projection area in the second plane that is farthest from the optical axis and the optical axis; the eighth central projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the second returning surface; v12d1 is the distance between the point of the fifth central projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth central projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time; v12d2 is the distance between the point farthest from the optical axis in the eighth central projection area in the second plane and the optical axis.

7. The near-eye display module according to claim 4, characterized in that: 2mm<D<8mm, 2mm<D0<8mm.

8. The near-eye display module according to claim 2, characterized in that: The projection shapes of the first transmission area and the second reflection area along the optical axis are the same, and are both rectangular, elliptical or irregular polygonal.

9. The near-eye display module according to claim 1, characterized in that: The folded imaging system comprises a transmissive polarizer, a first quarter wave plate, a lens subsystem, a second quarter wave plate and a reflective polarizer which are sequentially arranged along the optical axis; The lens subsystem at least includes a first lens, the first folding surface is located on the object side surface of the first lens; the first folding surface includes a first transmission area and a first reflection area, the first reflection area surrounds the first transmission area; the second folding surface is located on the reflective polarizer; Along the optical axis direction, the projection of the display screen is located in the projection of the first transmission area; At least part of the light emitted from any position on the display screen is sequentially transmitted through the transmission polarizer to form horizontal polarized light, transmitted through the first quarter-wave plate to form right-handed circularly polarized light, transmitted through the first transmission area, transmitted through the second quarter-wave plate to form horizontal polarized light, reflected through the reflective polarizer, transmitted through the second quarter-wave plate to form right-handed circularly polarized light, reflected through the first reflection area to form left-handed circularly polarized light, transmitted through the second quarter-wave plate to form vertically polarized light, and transmitted through the reflective polarizer to the coupling-in area of ​​the one-dimensional optical waveguide.

10. The near-eye display module according to claim 9, characterized in that: The first transmission area of ​​the object-side surface of the first lens is provided with a first transmission film, and the first reflection area is provided with a first reflection film.

11. The near-eye display module according to claim 9, characterized in that: The reentry imaging system comprises a first plane and a second plane, wherein the first plane and the second plane are perpendicular to each other and intersect at the optical axis of the reentry imaging system; The first transmission area and the first reflection area are both symmetrical relative to the first plane, and are also symmetrical relative to the second plane; wherein: h>A; v>B; Wherein, h is the length of the intersection line between the first transmission area and the first plane; A is the length of the intersection line between the display screen and the first plane; v is the length of the intersection line between the first transmission area and the second plane; B is the length of the intersection line between the display screen and the second plane.

12. The near-eye display module according to claim 11, characterized in that: h22c1<h / 2<h22c2; or, h22a1<h / 2<h22a2; v22c1 is the distance between the point of the first edge projection area in the first plane that is closest to the optical axis and the optical axis; the first edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen on the first plane on the first returning surface for the first time; h22c2 is the distance between the point of the second edge projection area in the plane closest to the optical axis and the optical axis; the second edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane on the first return surface for the second time; h22a1 is the distance between the point of the first edge projection area in the plane that is farthest from the optical axis and the optical axis; the first edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane on the first returning surface for the first time; h22a2 is the distance between the point of the second edge projection area in the plane that is farthest from the optical axis and the optical axis; the second edge projection area is the projection area of ​​the outgoing light beam at the edge point of the display screen in the plane on the first return surface for the second time; h12a1<h / 2<h12a2; h12a1 is the distance between the point of the first central projection area in the plane that is farthest from the optical axis and the optical axis; the first central projection area is the projection area of ​​the outgoing light beam at the center point of the display screen in the plane on the first reflecting surface for the first time; h12a2 is the distance between the point farthest from the optical axis in the second central projection area in the plane and the optical axis; the second central projection area is the second projection area of ​​the outgoing light beam from the center point of the display screen in the plane on the first returning surface.

13. The near-eye display module according to claim 11, characterized in that: v22f1<v / 2<v22f2; or, v22d1<v / 2<v22d2; v22f1 is the distance between the point of the fifth edge projection area in the second plane that is closest to the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time; v22f2 is the distance between the point of the sixth edge projection area in the second plane that is closest to the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface; v22d1 is the distance between the point of the fifth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth edge projection area is the projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface for the first time; v22d2 is the distance between the point of the sixth edge projection area in the second plane that is farthest from the optical axis and the optical axis; the sixth edge projection area is the second projection area of ​​the outgoing light beam from the edge point of the display screen on the second plane on the first returning surface; v12d1<v / 2<v12d2; v12d1 is the distance between the point of the fifth central projection area in the second plane that is farthest from the optical axis and the optical axis; the fifth central projection area is the projection area of ​​the outgoing light beam from the center point of the display screen on the second plane on the first returning surface for the first time; v12d2 is the distance between the point farthest from the optical axis in the eighth central projection area in the second plane and the optical axis; the eighth central projection area is the second projection area of ​​the outgoing light beam from the center point of the display screen on the second plane on the first returning surface.

14. The near-eye display module according to claim 2 or 9, characterized in that: The first lens is a meniscus lens convex toward the display screen.

15. The near-eye display module according to claim 2 or 9, characterized in that: The object side surface or the image side surface of the first lens is a spherical surface, an aspherical surface, a free-form surface or a diffractive surface.

16. The near-eye display module according to claim 1, characterized in that: The catadioptric imaging system has positive optical power.

Images