CN114217375A - High-brightness-uniformity diffraction light waveguide device and head-mounted AR (augmented reality) display equipment - Google Patents
High-brightness-uniformity diffraction light waveguide device and head-mounted AR (augmented reality) display equipment Download PDFInfo
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- 210000001747 pupil Anatomy 0.000 description 5
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
- G02B6/0031—Reflecting element, sheet or layer
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/017—Head mounted
- G02B27/0172—Head mounted characterised by optical features
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0055—Reflecting element, sheet or layer
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2066—Reflectors in illumination beam
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Abstract
The invention discloses a diffraction light waveguide device with high brightness uniformity and a head-mounted AR display device, wherein the diffraction light waveguide device comprises: the optical waveguide device comprises an optical waveguide device body and at least one transflective film layer in the optical waveguide device body; the optical waveguide device body is provided with an optical wave channel, the optical wave channel is provided with a first reflecting surface and a second reflecting surface which are opposite, incident light is reflected between the first reflecting surface and the second reflecting surface and propagates along the extending direction of the optical wave channel, the transflective film layer is positioned in the optical wave channel and extends in the same direction with the optical wave channel, and the transflective film layer is used for reflecting one part of the light incident on the transflective film layer to the first reflecting surface and transmitting the other part of the light to the second reflecting surface; and reflecting a part of the reflected light of the second reflecting surface to the second reflecting surface and transmitting the other part to the first reflecting surface. Through the mode of gradually increasing light density in the propagation path, the problem that in the prior art, the light is attenuated in the energy in the beam splitting propagation process, so that the brightness is uneven when the pure-color image is displayed on the optical waveguide is solved.
Description
Technical Field
The invention relates to the field of AR equipment, in particular to a diffraction light waveguide device with high brightness uniformity and head-mounted AR display equipment.
Background
A head mounted AR display device enables both real world real scenes and computer generated virtual content images to be imaged on the retina via the human eye simultaneously. The optical waveguide is a device that can confine signal light inside and transmit the signal light in a specific direction, and has good optical transparency. Based on these characteristics, the optical waveguide may serve as a display for an Augmented Reality (AR) near-eye display device. The optical waveguide directionally transmits the signal light projected by the projection light machine to human eyes, so that the human eyes can see the image to be displayed, and because the optical waveguide has good light transmission, the human eyes can clearly see the real environment behind the optical waveguide, so that the human eyes finally see the fusion of the image to be displayed and the real environment.
The existing optical waveguide can cause the attenuation of energy in the beam splitting and propagation process of light rays, and the brightness is weaker along with the longer propagation distance, so that the problem of uneven brightness when the waveguide displays a pure-color image is caused.
Accordingly, the prior art is yet to be improved and developed.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention provides a diffractive light waveguide device with high brightness uniformity and a head-mounted AR display apparatus, which solve the problem of uneven brightness when the light waveguide displays a pure color image due to energy attenuation during the beam splitting propagation process in the prior art.
The technical scheme of the invention is as follows:
a high brightness uniformity diffractive optical waveguide device comprising: the optical waveguide device comprises an optical waveguide device body and at least one transflective film layer in the optical waveguide device body;
the optical waveguide device body is provided with a lightwave channel for light propagation, the lightwave channel is provided with a first reflecting surface and a second reflecting surface which are opposite, and incident light propagates along the extending direction of the lightwave channel by being reflected between the first reflecting surface and the second reflecting surface;
the transflective film layer is positioned in the light wave channel and extends in the same direction as the light wave channel, and is used for reflecting one part of light incident on the transflective film layer to the first reflecting surface and transmitting the other part of the light to the second reflecting surface; and reflecting a part of the reflected light of the second reflecting surface to the second reflecting surface and transmitting the other part to the first reflecting surface.
Furthermore, the transflective film layer comprises a single piece of semi-transparent and semi-reflective film, and the single piece of semi-transparent and semi-reflective film is continuously arranged along the extending direction of the light wave channel.
Further, the transflective film layer includes: the light-modulating device comprises a plurality of semi-transparent semi-reflective membranes, wherein the semi-transparent semi-reflective membranes are arranged at intervals along the extending direction of a light wave channel, and a light-modulating channel is formed between adjacent semi-transparent semi-reflective membranes.
Further, the density of the dimming channels near the distal end of the lightwave channel is less than the density of the dimming channels near the proximal end of the lightwave channel.
Further, the transparent and reflective film layer is provided with a plurality of layers, and the plurality of layers of transparent and reflective film layers are arranged between the first reflecting surface and the second reflecting surface at intervals.
Further, the interval distance between the adjacent transflective film layers is the same or different
Further, the number of layers along the transflective film layer near the coupling-in area is smaller than the number of layers along the transflective film layer near the coupling-out area.
Furthermore, the surface of the coupling-out region is parallel to the transflective film layer.
Further, the optical waveguide device body is provided with a coupling-in area and a coupling-out area; the coupling-out region is internally provided with the transflective film layer; or
The optical waveguide device body is provided with a coupling-in area, a coupling-out area and a turning area, the turning area is communicated with the coupling-in area and the coupling-out area, and the coupling-out area and the turning area are internally provided with the transflective film layer.
Further, the boundary contour of the transflective film layer is formed into a curve shape;
the coupling-out area comprises a plurality of corners, and the number of the transflective film layers facing the corners of the coupling-in area is less than that of the transflective film layers far away from the corners of the coupling-in area.
Further, each transflective film layer has a plurality of sub-regions, including a transflective region and a non-transflective region.
Based on the same concept, the present invention also provides a head-mounted AR display device, comprising: the diffraction light waveguide device is used for directionally transmitting the signal light projected by the projection light machine to human eyes.
Has the advantages that: compared with the prior art, the invention provides the diffraction light waveguide device with high brightness uniformity and the head-mounted AR display equipment. When the light in the diffraction light waveguide device passes through the transflective film layer each time, the light is divided into two beams: reflected light and transmitted light. The reflected light is reflected to the first reflecting surface, then is reflected to the transflective film layer from the first reflecting surface, and continues to split the beam; the transmitted light is transmitted to the second reflecting surface, and then is reflected to the transflective film layer from the second reflecting surface, and beam splitting is continued; therefore, as the light propagates along the extending direction of the light wave channel, the more times the light penetrates through the transflective film layer, the more the number of the light is, and the greater the density of the light emitted from the coupling-out region per unit area is. The light density in the waveguide is increased along with the increase of the propagation distance, the original process that the brightness is weaker due to the longer distance is compensated, the light density of an area with weak energy attenuation on the optical waveguide is small, the light density of an area with strong energy attenuation on the optical waveguide is large, and therefore the light emitting brightness of the light emitting area of the whole optical waveguide is uniform, the problem that the display brightness of the optical waveguide is not uniform is compensated.
Drawings
FIG. 1 is a schematic structural view of a conventional optical waveguide device body;
FIG. 2 is a schematic optical path diagram of a conventional optical waveguide device body;
FIG. 3 is a schematic view of the light attenuation of a conventional optical waveguide device body;
FIG. 4 is a comparison graph of a desired display effect and a conventional display effect;
FIG. 5 is a diagram showing the optical path comparison between a diffraction optical waveguide device with high brightness uniformity according to the present invention and a conventional optical waveguide device;
FIG. 6 is an optical diagram of one configuration of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention;
FIG. 7 is a cross-sectional view of an alternative configuration of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention;
FIG. 8 is a cross-sectional view of a preferred construction of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention;
FIG. 9 is a three-dimensional view of a preferred structure of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention;
FIG. 10 is a schematic optical path diagram of an embodiment of a diffractive optical waveguide device of the present invention having high brightness uniformity;
FIG. 11 is a front view of a preferred construction of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention;
FIG. 12 is a front view of another configuration of an embodiment of a high brightness uniformity diffractive optical waveguide device in accordance with the present invention.
The reference numbers in the figures: 100. an optical waveguide device body; 110. a coupling-in region; 120. a turning region; 130. a coupling-out region; 131. a corner; 140. a light wave channel; 141. a first reflective surface; 142. a second reflective surface; 200. a transflective film layer; 210. a semi-permeable and semi-reflective membrane; 220. a dimming channel; 230. a transflective region; 240. no trans-reflection region; 300. a diffractive microstructured layer.
Detailed Description
The present invention provides a diffraction light waveguide device with high brightness uniformity and a head-mounted AR display device, and in order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below by referring to the drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Optical waveguide devices can be classified into geometrical optical waveguides, diffraction optical waveguides, and the like according to different implementation principles. Diffractive optical waveguides have become a preferred choice for displays in Augmented Reality (AR) near-eye display devices because of their advantages such as thin thickness, light weight, and good optical transparency. As shown in fig. 1 a1, a2 and b, the diffractive optical waveguide device is composed of an optical waveguide device body 100 and a diffractive microstructure layer 300 on the surface of the optical waveguide device body 100. The diffractive microstructure layer 300 includes, but is not limited to, surface relief gratings, volume holographic gratings, nanostructured surfaces, and combinations of the aforementioned 3 diffractive microstructures. As shown in a1 in fig. 1, on the surface of the waveguide device body, the area near the optical projector is the coupling-in area 110, the area near the human eye is the coupling-out area 130, and a turning area 120 may exist between the coupling-in area 110 and the coupling-out area 130. As shown in fig. 1 b, there may be only a coupling-in region 110 and a coupling-out region 130. The diffractive microstructure layers 300 of the coupling-in region 110, the turning region 120 and the coupling-out region 130 can be on the same surface of the optical waveguide device body 100, or can be respectively located on two opposite surfaces of the optical waveguide device body 100 (the diffractive microstructures of the coupling-in region 110, the turning region 120 and the coupling-out region 130 of the diffractive optical waveguide shown in fig. 1 are located on the same surface of the optical waveguide device body 100).
The diffractive micro-structure layer 300 of the in-coupling region 110 couples a part of the signal light emitted from the optical engine into the optical waveguide device body 100 by means of diffraction of the light, and the diffractive micro-structure layers 300 of the transition region 120 and the out-coupling region 130 can split and expand a beam of light transmitted therein in two dimensions by means of diffraction of the light, so that the beam of light incident from the in-coupling region 110 is expanded into a plurality of beams of light after being transmitted and coupled out by means of the waveguide, i.e. pupil expansion, and the light propagation process is shown in fig. 2 a and b. As shown in a of fig. 2, for the waveguide with the turning region 120, the light beams are transmitted to the out-coupling region 130 through the turning region 120 and total reflection in the waveguide device body. As shown in b of fig. 2, for the waveguide having only the coupling-in region 110 and the coupling-out region 130, the light beams are transmitted to the coupling-out region 130 through total reflection in the optical waveguide device body 100. The diffractive micro-structure layer 300 of the coupling-out region 130 uses diffraction of light to guide the optical waveguide device bodyThe light transmitted in the light guide device 100 is coupled out of the light guide device body 100, and the light coupled out of the light guide device body 100 is incident to human eyes to form an image to be displayed on a retina. For a light ray of a specific propagation angle and a fixed period of the diffractive microstructure, the diffraction efficiencies of the diffractive microstructure layer 300 of the inflection region 120 and the diffractive microstructure layer 300 of the outcoupling region 130 are fixed, which results in attenuation of the energy of the light ray during the propagation of the beam splitting. Taking the waveguide with the transition region 120 as an example, as shown in fig. 3, where R0 is the incident signal light, and assuming that the energy is 1, the 1 st order diffraction efficiency of the micro-structure layer 300 diffracted by the transition region 120 for the light is α (α)<1) Then, the energies of the turning rays R1, R2 and R3 are respectively alpha, (1-alpha) alpha and (1-alpha)2α, the energy is seen to be decreasing. Similarly, in the coupling-out region 130, the diffraction efficiency of the emergent ray order corresponding to the diffractive micro-structure layer 300 of the coupling-out region 130 is β (β)<1) The energy of the outcoupled light rays R11, R12 and R13 are respectively alpha beta, alpha (1-beta) beta and alpha (1-beta)2β, the energy of which is also decreasing. The relative energy of all the coupled-out light rays is represented by the length of the light rays, and shows a tendency to sequentially decay from the upper left corner of the coupling-out region 130 to the lower right corner of the coupling-out region 130, as shown in the graph b1 in fig. 4, which causes a problem of uneven brightness when the waveguide displays a pure color image. And the image in the ideal state is shown as a1 in fig. 4, and the brightness is uniform.
To solve the problem of brightness non-uniformity when the waveguide displays a pure color image, as shown in fig. 5, wherein a in fig. 5 is an optical path diagram of a conventional optical waveguide, and b in fig. 5 is an optical path diagram of a diffractive light waveguide device with high brightness uniformity according to this embodiment, the diffractive light waveguide device includes: the optical waveguide device body 100 and the at least one transflective film layer 200 in the optical waveguide device body 100 form an optical wave channel 140 between the coupling-in region 110 and the coupling-out region 130 of the optical waveguide device body 100, and the optical wave channel 140 extends into the coupling-out region 130, that is, the coupling-out region 130 has the optical wave channel 140 therein, in this embodiment, the optical wave channel 140 located in the coupling-out region 130 is mainly used for description. The optical wave channel 140 has a first reflective surface 141 and a second reflective surface opposite to each other, and incident light propagates from the coupling-in region 110 to the coupling-out region 130 by being reflected between the first reflective surface 141 and the second reflective surface, so that the extending direction of the optical wave channel 140 is the propagation direction of the incident light, one end of the optical wave channel 140 close to the coupling-in region 110 is a proximal end, and one end facing the coupling-out region 130 is a distal end; incident light is transmitted from the proximal end of the lightwave channel 140 to the distal end of the lightwave channel 140. The transflective film layer 200 is located in the light wave channel 140 and extends in the same direction as the light wave channel 140, so that the transflective film layer 200 extends along the light propagation direction (diffusion direction). The transflective film layer 200 in this embodiment may be a transflective film, and the transflective film layer 200 is used to reflect a part of light incident thereon to the first reflecting surface 141 and transmit another part to the second reflecting surface 142; and reflecting a part of the light reflected by the second reflecting surface 142 to the second reflecting surface 142 and transmitting another part to the first reflecting surface 141, so that the light continuously passes through the transflective film layer 200 in the propagation direction.
As shown in fig. 5 and 6, when the light in the diffractive light waveguide device is split into two beams by passing the light through the transflective film layer 200 each time: reflected light and transmitted light. The reflected light is reflected to the first reflecting surface 141, and then reflected to the transflective film layer 200 from the first reflecting surface 141, and continues to split the beam; the transmitted light is emitted to the second reflecting surface 142, and then is reflected to the transflective film layer 200 from the second reflecting surface 142 to continue beam splitting; therefore, as the light propagates along the extending direction of the light wave channel 140, the more times the light penetrates the transflective film layer 200, the greater the amount of the light, and the greater the density of the light emitted from the coupling-out region 130 per unit area. The light density in the waveguide is increased along with the increase of the propagation distance (the light at the near end is sparse, the light at the far end is dense), the original process that the brightness is weaker due to the longer distance is compensated, the light density of an area with weak energy attenuation on the optical waveguide is small, the light density of an area with strong energy attenuation on the optical waveguide is large, the light-emitting brightness of the light-emitting area of the whole optical waveguide is uniform, the problem of nonuniform display brightness of the optical waveguide is compensated, and the structural scheme of the diffraction light waveguide device can realize the display effect with higher brightness uniformity.
As shown in fig. 6, in one structure, the transflective film layer 200 includes a single piece of transflective film 210, and the single piece of transflective film 210 is continuously disposed along the extending direction of the optical wave channel 140. The transflective film 210 is integrally disposed, and a single integral transflective film 210 is disposed between the first reflective surface 141 and the second reflective surface, so that light continuously passes through the single transflective film 210, and the longer the light extends in the transmission direction, the denser the emergent light is, thereby realizing the function of uniform brightness. Moreover, the monolithic transflective film 210 is easy to process, so that the cost of the whole optical waveguide device is low.
As shown in fig. 7, in another structure, the transflective film layer 200 includes: the transflective films 210 are arranged at intervals along the extending direction of the light wave channel 140, and a light modulation channel 220 is formed between adjacent transflective films 210, so that light rays directly pass through the light modulation channel 220 without being influenced. The plurality of semi-transparent and semi-reflective membranes 210 on one layer are arranged at intervals, and the size of the intervals is adjusted according to the shape of the coupling-out region 130 or the turning region 120. Therefore, the transflective film layer 200 can be applied to the structures of the coupling-out region 130 or the turning region 120 with various shapes, and the size of the interval is adjusted to form different regions with different brightness enhancement effects, thereby finally achieving the purpose of uniform overall brightness.
For the spaced apart transflective membranes 210, the density of the dimming channels 220 near the distal end of the lightwave channel 140 is less than the density of the dimming channels 220 near the proximal end of the lightwave channel 140. The density of the dimming channels 220 refers to the occupied area of the dimming channels 220 in a certain area, and the small density of the dimming channels 220 refers to the small number of the dimming channels 220 or/and the small area of the dimming channels 220. The density of the light modulation channels 220 close to the coupling-in region 110 is high, so that the light passes through the light modulation channels 220 at the position close to the coupling-in region 110, and the transmission and reflection parts on the transflective film 210 are low, so that the light density at the position close to the coupling-in region 110 is low, and the brightness compensation amount is small; the dimming channel 220 near the coupling-out region 130 has a small density, so that the light passing through the dimming channel 220 at a position near the coupling-out region 130 has a small amount, and the light passing through the transflective film 210 has a large amount of light passing through the dimming channel 220, so that the light passing through the coupling-out region 130 has a large density, and the luminance compensation amount is large, thereby making the overall brightness uniform.
As shown in fig. 7 and 8, the two structures may be combined, for example, the transflective film layer 200 in this embodiment is provided with multiple layers, and the multiple layers of the transflective film layer 200 are spaced between the first reflective surface 141 and the second reflective surface. Each transflective film 210 can modulate the light intensity in both continuous and discontinuous states. The light guide with the structure can increase the density of the outcoupled light along the propagation path by special design, and uniformly distribute the light energy to the diffraction light in the pupil expansion direction to compensate the energy of the light which is reduced along with the increase of the propagation path.
The multi-layer transflective film layer 200 in this embodiment is at least provided with two layers, and the distance between two layers of transflective film layers 200, the distance between one transflective film layer 200 and the first reflective surface 141, and the distance between the other transflective film layer 200 and the second reflective surface may be set to be equal, so that the multi-layer transflective film layer 200 is uniformly distributed between the first reflective surface 141 and the second reflective surface, and uniform light distribution can be achieved. The multilayer transflective film layers 200 in this embodiment are unevenly distributed, and the distance between the transflective film layers 200 can be used as an optimization variable matched with the characteristics of the optical waveguide device body, and can be optimized along with the overall performance of the waveguide, so as to obtain a distance capable of optimizing the indexes such as waveguide uniformity and brightness.
In the multi-layer transflective film layer 200 of the present embodiment, the number of layers along the transflective film layer 200 near the proximal end of the optical wave channel 140 is smaller than the number of layers of the transflective film layer 200 near the distal end of the optical wave channel 140. Each time the light passes through the partially transflective film, the light is split into two beams. Therefore, as the light propagates, the more partial transflective films are encountered, the greater the number of light rays, and the greater the density of light rays emitted per unit area of the outcoupling region 130. As shown in fig. 9 (fig. 9, a is a front view of the optical waveguide device body 100, b is a bottom view of the optical waveguide device body 100, and c is a left view of the optical waveguide device body 100), wherein an area surrounded by dotted lines is a transflective film layer 200, taking the coupling-out area 130 in this embodiment as an example, the coupling-out area 130 is provided with two transflective film layers 200, and one transflective film layer 200 is added each time along the pupil expansion direction of the coupling-out area 130, and the area thereof is gradually reduced. As shown in fig. 10, therefore, the amount of light gradually increases in the pupil expansion direction of the turning region 120 and the coupling-out region 130, and thus the light thereof gradually increases.
The optical waveguide device body 100, in one form, has only a coupling-in region 110 and a coupling-out region 130. The coupling-out region 130 is disposed on a surface parallel to the transflective film layer 200. Thereby enabling the transflective film layer 200 in the coupling-out region 130 to compensate for the display brightness of the optical waveguide according to the region with strong energy attenuation on the optical waveguide.
In one form of the optical waveguide device body 100, the optical waveguide device body 100 further has a turning region 120, the turning region 120 connects the coupling-in region 110 and the coupling-out region 130, and the turning region 120 is used for changing the direction of the optical wave channel 140; the turning region 120 is also provided with a transflective film layer 200.
The amount of light in the optical waveguide device body 100 varies with the propagation path as shown in fig. 10. The incident light ray R0 enters from the coupling-in region, and is diffracted every time the surface of the diffractive micro-structure layer 300 incident on the inflection region 120 or the coupling-out region 130, so as to generate the inflection light ray R1 or the coupling-out light ray R2. Therefore, the quantity of the inflected light and the outcoupled light is directly related to the quantity of the light incident on the surface of the diffractive micro-structure layer 300 of the inflection region 120 and the outcoupled region 130. The greater the amount of light diffracted at the locations of the transflective film layer 200 having the greater number of layers, the greater the density of pupil expansion there at the turning region 120 and the outcoupling region 130. This waveguide arrangement ensures that the light density is greater where the energy of a single light ray is weaker in the outcoupling region 130. Therefore, the brightness difference of the waveguide display area can be reduced, and the brightness uniformity is improved.
In another embodiment, as shown in fig. 11, each transflective film layer 200 may have a plurality of sub-regions having two states, a transflective region 230 and an unpermeable region 240, as shown in fig. 10. By optimally designing the number, position and shape of the transflective regions 230, an optical waveguide with high brightness uniformity can be obtained. When the optical waveguide device body 100 only has the coupling-in region and the coupling-out region, the coupling-out region only has the plurality of layers of the transflective film layers 200 with the plurality of sub-regions, so that the effect of uniform light brightness of the optical waveguide device body 100 is achieved.
As shown in fig. 12, the boundary profile of the transflective film layer 200 is formed in a curved shape according to the attenuation characteristics of the transferred energy of the optical waveguide device body 100, the coupling-out region 130 includes a plurality of corners 131, and the number of layers of the transflective film layer 200 toward the corners 131 of the coupling-in region 110 is less than the number of layers of the transflective film layer 200 away from the corners of the coupling-in region 110. That is, the number of transflective film layers 200 disposed at the corners of the proximal end of the optical wave channel 140 is less than the number of transflective film layers 200 disposed at the corners of the distal end of the optical wave channel 140. Specifically, as shown in fig. 11, the shape of each layer of the partially transparent and reflective film in the optical waveguide device body 100 may be any shape, and each curve in the turning region 120 and the coupling-out region 130 is a boundary of each layer of the partially transparent and reflective film, and the boundary may be a straight line or a broken line, which is not limited herein. In this embodiment, the turning region 120 has three transflective film layers 200, and the coupling-out region 130 has five transflective film layers 200. Therefore, relatively more transflective film layers 200 can be disposed at the corners of the coupling-out region 130 or the turning region 120 to compensate for the attenuation of the light energy at the corners.
Based on the same concept, the present invention also provides a head-mounted AR display device, comprising: the diffraction light waveguide device is used for directionally transmitting the signal light projected by the projection light machine to human eyes.
In summary, the invention provides a diffraction light waveguide device with high brightness uniformity and a head-mounted AR display device. The one or more layers of the transflective film layers are arranged in the optical waveguide device body, and the transflective film layers are used for splitting light and expanding the quantity of the light, so that the light density in the optical waveguide device body is increased along with the increase of the propagation distance, the attenuation of the display brightness of the optical waveguide along with the lengthening of the propagation distance is compensated, and the display effects of higher brightness and uniform luminescence of the diffraction light waveguide device can be realized.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.
Claims (10)
1. A diffractive light waveguide device of high brightness uniformity, comprising: the optical waveguide device comprises an optical waveguide device body and at least one transflective film layer in the optical waveguide device body;
the optical waveguide device body is provided with a lightwave channel for light propagation, the lightwave channel is provided with a first reflecting surface and a second reflecting surface which are opposite, and incident light propagates along the extending direction of the lightwave channel by reflecting between the first reflecting surface and the second reflecting surface;
the transflective film layer is positioned in the light wave channel and extends in the same direction as the light wave channel, and is used for reflecting one part of light incident on the transflective film layer to the first reflecting surface and transmitting the other part of the light to the second reflecting surface; and reflecting a part of the reflected light of the second reflecting surface to the second reflecting surface and transmitting another part to the first reflecting surface.
2. The diffractive optical waveguide device according to claim 1, wherein said transflective film layer includes a single piece of transflective film, and said single piece of transflective film is continuously disposed along an extending direction of said optical wave channel.
3. A high brightness uniformity diffractive optical waveguide device according to claim 1, wherein said transflective film layer comprises: the light wave channel is formed by a plurality of semi-transparent semi-reflective membranes, a plurality of semi-transparent semi-reflective membranes are arranged at intervals along the extending direction of the light wave channel, and the semi-transparent semi-reflective membranes are adjacent to each other to form a light modulation channel.
4. The high brightness uniformity diffractive optical waveguide device according to claim 3, wherein the density of said dimming channels near the distal end of said lightwave channel is less than the density of said dimming channels near the proximal end of said lightwave channel.
5. A high brightness uniformity diffractive light waveguide device according to any of claims 1-4, wherein said transflective film layer is provided in a plurality of layers, said plurality of layers being spaced apart between said first reflective surface and said second reflective surface.
6. The diffractive optical waveguide device according to claim 5, characterized in that the distance between adjacent transflective film layers is the same or different.
7. The high brightness uniformity diffractive optical waveguide device according to claim 5, wherein the number of layers along said transflective film layer near the proximal end of said light channel is less than the number of layers near the distal end of said light channel.
8. A high brightness uniformity diffractive light waveguide device according to claim 1 wherein said light waveguide device body has a coupling-in region, a coupling-out region; the coupling-out region is internally provided with the transflective film layer; or
The optical waveguide device body is provided with a coupling-in area, a coupling-out area and a turning area, the turning area is communicated with the coupling-in area and the coupling-out area, and the coupling-out area and the turning area are internally provided with the transflective film layer.
9. The high brightness uniformity diffractive optical waveguide device according to claim 8, wherein the boundary profile of the transflective film layer is formed in a curved shape;
the coupling-out area comprises a plurality of corners, and the number of the transparent and reflective film layers at the corners facing the coupling-in area is less than that at the corners far away from the coupling-in area;
or
Each of the transflective film layers has a plurality of sub-regions including a transflective region and a non-transflective region.
10. A head-mounted AR display device, comprising: a projector engine, and a diffractive optical waveguide device according to any one of claims 1 to 9 for directionally transmitting signal light projected by the projector engine to the human eye.
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| CN116609036A (en) * | 2023-05-15 | 2023-08-18 | 南方科技大学 | Method and device for measuring uniformity of AR optical waveguide |
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