CN117539059A - Large eye box crosstalk-free holographic optical waveguide augmented reality display device - Google Patents
Large eye box crosstalk-free holographic optical waveguide augmented reality display device Download PDFInfo
- Publication number
- CN117539059A CN117539059A CN202311284667.4A CN202311284667A CN117539059A CN 117539059 A CN117539059 A CN 117539059A CN 202311284667 A CN202311284667 A CN 202311284667A CN 117539059 A CN117539059 A CN 117539059A
- Authority
- CN
- China
- Prior art keywords
- sub
- light
- holographic optical
- optical element
- pdlc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 226
- 230000003190 augmentative effect Effects 0.000 title claims abstract description 26
- 239000004983 Polymer Dispersed Liquid Crystal Substances 0.000 claims abstract description 83
- 230000010076 replication Effects 0.000 claims abstract description 53
- 210000001508 eye Anatomy 0.000 claims abstract description 43
- 238000010168 coupling process Methods 0.000 claims abstract description 17
- 238000005859 coupling reaction Methods 0.000 claims abstract description 17
- 238000002834 transmittance Methods 0.000 claims abstract description 17
- 230000005540 biological transmission Effects 0.000 claims abstract description 10
- 230000000007 visual effect Effects 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims description 15
- 210000001747 pupil Anatomy 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 claims description 6
- 238000002310 reflectometry Methods 0.000 claims description 4
- 229920000106 Liquid crystal polymer Polymers 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 3
- 239000011159 matrix material Substances 0.000 claims description 3
- 230000001902 propagating effect Effects 0.000 claims 1
- 230000008878 coupling Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 35
- 238000010586 diagram Methods 0.000 description 6
- 210000005252 bulbus oculi Anatomy 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- 210000001525 retina Anatomy 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- 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
-
- 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
-
- 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
- G02B2027/0174—Head mounted characterised by optical features holographic
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Diffracting Gratings Or Hologram Optical Elements (AREA)
Abstract
The invention provides a large-eye-box crosstalk-free holographic optical waveguide augmented reality display device which comprises a projection module, a wavefront replication module, an in-coupling module, a waveguide and an out-coupling module. The projection module has the functions of projecting an image source and collimating the projected light waves. The wave front replication module replicates the light waves output by the projection module into six-beam planar light waves. The in-coupling module couples six planar lightwaves generated by the wave front replication module into the waveguide, and realizes the switching of the lightwaves through a PDLC (polymer dispersed liquid crystal, PDLC) module in the in-coupling module. The waveguide provides a total reflection transmission channel for the coupled light waves and has good optical transmittance for ambient light. The decoupling module is used for coupling and converging light waves in the waveguide at a certain diffraction angle to form nine viewpoints which are distributed in a 3 multiplied by 3 mode, and the optical axis of each viewpoint is coincident with the visual axis of eyes at corresponding positions.
Description
Technical Field
The invention belongs to the technical field of near-eye display, and particularly relates to a large-eye-box crosstalk-free holographic optical waveguide augmented reality display device.
Background
Augmented reality is a new display technology that superimposes virtual images in a real scene. The image source projects virtual images onto a transparent medium in front of the human eye, light rays of these virtual images can enter the human eye by reflection or diffraction, etc., and light rays of a real scene can also enter the human eye through the transparent medium without deformation. Therefore, the augmented reality device can acquire real-world information in real time while acquiring virtual image information, so that the immersion of a viewer and the instantaneity of acquiring information are greatly improved.
The holographic optical waveguide is a technical route for realizing augmented reality display, an image source optical wave is coupled into the waveguide through a volume holographic grating or a prism, the optical wave is transmitted in the waveguide by utilizing total reflection, and finally the optical wave is transmitted into eyes through the volume holographic grating in front of pupils. The volume holographic grating is a holographic optical element, can replace one or more elements in an optical system, reduces the volume of the system, reduces the redundancy of the system, is easy to integrate, has the dual functions of imaging and optical perspective, and is widely applied to augmented reality display. However, the conventional holographic optical waveguide augmented reality device can only generate one viewpoint due to only one recorded outcoupling wavefront, so that the eye box is greatly limited. Eye-box expansion is a technical bottleneck that needs to be broken through by the current augmented reality display device.
Disclosure of Invention
The invention provides a large-eye-box crosstalk-free holographic optical waveguide augmented reality display device, which is shown in figure 1 and comprises a projection module (100), a wavefront replication module (200), an in-coupling module (300), a waveguide (400) and an out-coupling module (500). The projection module (100) comprises a projector (101) and a collimating lens (102), and has the functions of projecting an image source and collimating projected light waves. The wavefront replication module (200) comprises a vertical wavefront replication unit (210) and a horizontal wavefront replication unit (220). The wave front replication module (200) replicates the light waves output by the projection module (100) into six-beam planar light waves. The in-coupling module (300) comprises a polymer dispersed liquid crystal (polymer dispersed liquid crystal, PDLC) module (310) and a holographic optical element I (320), and the in-coupling module (300) couples six planar lightwaves generated by the wave front replication module (200) into the waveguide (400). The waveguide (400) provides a total reflection transmission path for the coupled-in light waves and has a good optical transmission for ambient light. The coupling-out module (500) comprises a holographic optical element II (510) and a holographic optical element III (520), the coupling-out module (500) couples and converges light waves in the waveguide (400) at a certain diffraction angle to form nine viewpoints which are distributed in a 3 multiplied by 3 mode, and the optical axis of each viewpoint is coincident with the visual axis of eyes at corresponding positions.
In the projection module (100), a projector (101) projects an image source to be displayed, and a collimator lens (102) collimates the projected light wave into a planar light wave L (700).
The wavefront replication module (200) comprises a vertical wavefront replication unit (210) and a horizontal wavefront replication unit (220). The vertical wavefront copying unit (210) further comprises a beam splitter I (211), a reflector I (212), a beam splitter II (213) and a reflector II (214), as shown in FIG. 2; the horizontal wavefront reproducing unit (220) further includes a beam splitter III (221) and a mirror III (222).
For convenience in describing the structure of the device, a three-dimensional coordinate system shown in fig. 1 is established, wherein the x-axis is the long axis direction of the waveguide, the z-axis is the short axis direction of the waveguide, the z-axis is the direction vertical to the paper surface, and the y-axis is the direction vertical to the waveguide surface.
The arrangement of the elements in the vertical wavefront copying unit (210) is shown in fig. 2, the beam splitting sheet I (211) forms 45 degrees with the z axis and the y axis, and the reflecting mirror I (212) and the beam splitting sheet I (211) are arranged in parallel along the z axis; the beam splitter II (213) forms an angle of 135 degrees with the y-axis, is perpendicular to the beam splitter I (211), and is positioned behind the beam splitter I (211) along the y-axis; the reflecting mirror II (214) and the light splitting sheet II (213) are arranged in parallel along the z axis. The light-splitting sheet I (211) and the light-splitting sheet II (213) have a certain proportion of reflection and transmission effects on incident light waves: the reflectance of the light-splitting sheet I (211) is R I Transmittance T I The method comprises the steps of carrying out a first treatment on the surface of the The reflectance of the light-splitting sheet II (213) is R II Transmittance T II . The intensity of the planar light wave L (700) output by the projection module is I, and the reflected light intensity is I multiplied by R after passing through the light splitting sheet I (211) I The transmitted light intensity is I×T I Wherein the light wave reflected by the beam splitter I (211) propagates along the z-axis to the mirror I (212) and is further reflected to generate a sub-planar light wave L 03 (703) The light wave transmitted by the light-splitting sheet I (211) propagates in the original direction to reach the light-splitting sheet II (213). A part of the light wave reaching the light-splitting sheet II (213) is reflected and a part of the light wave is transmitted, and the reflected light intensity is I x T I ×R II The transmitted light intensity is I×T I ×T II Wherein the light wave reflected by the beam splitter II (213) propagates along the z-axis to the mirror II (214) and is further reflected to generate a sub-planar light wave L 01 (701) The light wave transmitted by the light-splitting sheet II (213) generates a sub-planar light wave L 02 (702). The planar light waves incident into the vertical wavefront copying unit (210) are copied into three planar light waves, i.e. sub-planar light waves L, which are shifted in the z-axis direction 01 (701) Light waves L in sub-plane 02 (702) Light waves L in sub-plane 03 (703)。
The arrangement of the elements in the horizontal wavefront copying unit (220) is shown in fig. 2, the beam splitter plate III (221) forms an included angle of 45 ° with the x-axis and the y-axis, and the reflecting mirror III (222) and the beam splitter plate III (221) are arranged in parallel along the x-axis. The light-splitting sheet III (221) has a certain proportion of reflectivity and transmittance to the incident light wave: reflectance of the light-splitting sheet III (221) is R III Transmittance T III . Three sub-planar lightwaves L with a certain shift in the z-axis direction generated by a vertical wavefront copying unit 01 (701)、L 02 (702)、L 03 (703) Enters the horizontal wave front copying unit to reach the light splitting sheet III (221), the light wave reflected by the light splitting sheet III (221) propagates along the x-axis to reach the reflecting mirror III (222), and is further reflected to generate three sub-planar light waves, namely sub-planar light wave L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713). The sub-planar lightwave L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Has certain displacement along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L (700). The light waves transmitted by the beam-splitting sheet III (221) form three-beam replicated planar light waves, namely sub-planar light waves L 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716). The sub-planar lightwave L 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716) Has certain displacement along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L (700). The wave front copying module (200) is used for flattening the wave front generated by the projection module through two-stage wave front modulation of the vertical wave front copying unit and the horizontal wave front copying unitReplication of the surface light wave L (700) produces six sets of sub-planar light waves carrying the same image information, i.e., sub-planar light waves L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Light waves L in sub-plane 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716) As shown in fig. 2. The six sets of sub-planar lightwaves are arranged in an xz plane in a 2 x 3 array. Wherein the plane light wave is L 11 (711) Is of the intensity I x T I ×R II ×R III Sub-planar lightwave L 12 (712) Is of the intensity I x T I ×T II ×R III Sub-planar lightwave L 13 (713) Is of the intensity of I x R I ×R III Sub-planar lightwave L 14 (714) Is of the intensity I x T I ×R II ×T III Sub-planar lightwave L 15 (715) Is of the intensity I x T I ×T II ×T III Sub-planar lightwave L 16 (716) Is of the intensity of I x R I ×T III 。
In the coupling-in module, the PDLC module (310) is composed of six PDLC subunits, wherein each PDLC subunit has the same size, the length d and the width w, can transmit light under the condition of applying voltage and scatter light under the condition of not applying voltage. The arrangement of 6 PDLC subunits contained by the PDLC module (310) is shown in fig. 3 as being arranged in a 2 x 3 array in the xz-plane.
Six groups of sub-planar light waves generated by the wave front replication module (200) are incident in one-to-one correspondence with six PDLC subunits in the PDLC module (310), namely the sub-planar light waves L 11 (711) Incident PDLC-1 (311), sub-planar lightwave L 12 (712) Incident PDLC-2 (312), sub-planar lightwave L 13 (713) Incident PDLC-3 (313), sub-planar lightwave L 14 (714) Incident PDLC-4 (314), sub-planar lightwave L 15 (715) Incident PDLC-5 (315), sub-planar lightwave L 16 (716) Incident PDLC-6 (316).
As shown in fig. 4, the hologram optical element I (320) includes two sub-areas, i.e., left and right sub-areas of the hologram optical element I (320) having a length d and a width 3w, corresponding to three PDLC sub-units on the left side of the PDLC module (310), i.e., PDLC-4 (314), PDLC-5 (315), and PDLC-6 (316). After passing through the PDLC module (310), the light wave is diffracted on the holographic optical element I (320) and propagates in the xy-plane in a direction at an angle β to the positive y-axis direction. The right sub-region of holographic optical element I (320) is longer d, 3w wider, corresponding to the right three PDLC sub-cells in PDLC module (310), namely PDLC-1 (311), PDLC-2 (312), and PDLC-3 (313). After passing through the PDLC module (310), the light wave is diffracted on the holographic optical element I (320) and propagates in the xy-plane in a direction at an angle alpha to the y-axis. Both angles alpha and beta satisfy the total reflection condition of the waveguide (400).
The holographic optical element II (510) in the outcoupling module includes six sub-regions, as shown in fig. 5, namely, a holographic optical element II sub-region 1 (511), a holographic optical element II sub-region 2 (512), a holographic optical element II sub-region 3 (513), a holographic optical element II sub-region 4 (514), a holographic optical element II sub-region 5 (515) and a holographic optical element II sub-region 6 (516). Each holographic optical element II sub-region has the same size as the sub-cell of the PDLC module (310), and has a length d and a width w. Wherein three parallel light waves with the propagation angle alpha diffracted by the right side of the holographic optical element I (320) respectively reach three sub-areas on the left side of the holographic optical element II (510) to be diffracted, and the diffraction efficiency is eta left Three views on the left side, namely view 1 (801), view 2 (802), and view 3 (803), are generated. The undiffracted light continues to totally reflect within the waveguide (400), propagates to the sub-regions 4, 5 to 6 of the holographic optical element II (510), and diffracts with a diffraction efficiency η right Three viewpoints on the right side, namely, viewpoint 7 (807), viewpoint 8 (808), and viewpoint 9 (809), are generated, and the arrangement of viewpoints generated by the hologram optical element II (510) is shown in fig. 8.
The holographic optical element III (520) comprises three sub-regions, as shown in fig. 6, holographic optical element III sub-region 1 (521), holographic optical element III sub-region 2 (522), and holographic optical element III sub-region 3 (523), respectively. Each holographic optical element III subarea has the same size as the subarea of the holographic optical element II, has a length d and a width w, and three subareas are arranged in a row in the direction of the subareas of the holographic optical element I (320) and the holographic optical element II (510)The directions are the same. Three planar light waves with propagation angles beta diffracted out from the left side of the holographic optical element I (320) respectively reach three sub-areas of the holographic optical element III (520), and are diffracted, and the diffraction efficiency is eta center The three intermediate viewpoints, viewpoint 4 (804), viewpoint 5 (805) and viewpoint 6 (806), are generated, and the arrangement of viewpoints generated by the hologram optical element III (520) is shown in fig. 9.
Preferably, the reflectance of the light-splitting sheet I (211) is set toTransmittance is set to +.>The reflectance of the light-splitting sheet II (213) is set to +.>Transmittance is set to +.>The reflectance of the light-splitting sheet III (221) is set to +.>Transmittance is set to +.>The generated sub-planar lightwave L 11 、L 12 And L 13 The light intensity of (2) is +.>Sub-planar lightwave L 14 、L 15 And L 16 The light intensity of (2) is +.>The optical power of the formed viewpoints 801, 802, 803 are all +.>The optical power of the views 804, 805, 806 are all +.>Optical power of viewpoints 807, 808, 809The rate is +.> At the same time, eta left 、η center And eta max Is satisfied in relation to the (c) of the (c),
(1-η left )×η max ＝η center ＝η left ， (1)
the optical power of the generated nine viewpoints is the same and isSo that the brightness of the images obtained by the human eyes at different viewpoints is equalized.
The holographic optical element II (510) is bonded to the waveguide by an index matching fluid, and the holographic optical element III (520) is bonded to the holographic optical element II (510) by an index matching fluid. The light waves diffracted by the hologram optical element II (510) and the hologram optical element III (520) form a 3×3 viewpoint matrix, and the positional relationship of the respective viewpoints is shown in fig. 13.
Preferably, in order to make the images obtained by the human eye at the various viewpoints clearer, the images are imaged in the fovea of the retina of the human eye, the central points of the various viewpoints and the diffracted light waves thereof are arranged on the visual axis of the human eye, and particularly as shown in fig. 7, dh represents the distances between the left and right side viewpoints and the central viewpoint in the x-axis direction. The Dh is the number of the components,
Dh＝Rh×sinθ xy ， (2)
Wherein Rh is the horizontal rotation radius of eyeball, θ xy The rotation angles of the eyes are corresponding to the left and right side viewpoints in the xy plane. Similarly, the distance Dv between the upper and lower side view points and the central view point in the z-axis direction is,
Dv＝Rv×sinθ yz ， (3)
wherein Rv is the vertical radius of rotation of the eyeball, θ yz The rotation angles of the eyes are corresponding to the viewpoints at the upper side and the lower side in the yz plane.
In the xy planeChange theta xy After the angle, the exit pupil distance change delta Erh of the left and right side view points is,
ΔErh＝Rh×(1-sinθ xy )， (4)
human eyes rotate theta in yz plane yz After the angle, the change amount delta Erv of the exit pupil distance of the view points at the upper side and the lower side is,
ΔErv＝Rv×(1-sinθ yz )， (5)
the working principle of the large-eye-box crosstalk-free holographic optical waveguide augmented reality display device is as shown in fig. 1, the projector (101) projects divergent spherical light waves containing image information, and the collimating lens (102) collimates the divergent spherical light waves into planar light waves containing original image information; the planar light wave (700) is transmitted to the wave front replication unit (200), and is subjected to two-stage wave front replication by the vertical wave front replication unit (210) and the horizontal wave front replication unit (220) to generate six beams of planar light waves containing the same image information, namely sub-planar light waves L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Light waves L in sub-plane 14 (714) Light waves L in sub-plane 15 (715) Sub-planar lightwave L 16 (716) The method comprises the steps of carrying out a first treatment on the surface of the When the light wave passes through the PDLC and reaches the right area of the holographic optical element I (320), the holographic optical element I (320) diffracts the light wave to the alpha direction, the light wave is transmitted to the left side of the holographic optical element II (510) at the decoupling module through the waveguide (400), at the moment, part of the light wave is diffracted into convergent light at the left side of the holographic optical element II (510), the rest of the planar light wave is continuously totally reflected to the right side of the holographic optical element II (510), at the moment, the right side of the holographic optical element II (11) diffracts the incident light wave into convergent light; when the light wave passes through the PDLC to the left of the holographic optical element I (320), the holographic optical element I (320) diffracts it in the β direction, and the light wave passes through the waveguide (400) to reach the middle region of the holographic optical element II (510) at the outcoupling module. Since the Bragg condition corresponding to the holographic optical element II (510) is not satisfied, the light wave is transmitted through the holographic optical element II (510) to reach the surface of the holographic optical element III (520), the Bragg condition corresponding to the holographic optical element III (520) is satisfied, and the light wave is diffracted into convergent light; nine bundles are formed at the decoupling positionThe nine converging light beams respectively form a view point 1 (801), a view point 2 (802), a view point 3 (803), a view point 4 (804), a view point 5 (805), a view point 6 (806), a view point 7 (807), a view point 8 (808) and a view point 9 (809), a 3×3 view point array is formed, and the human eyes watch the same image information at the nine view points, so that the expansion of the eye box is realized.
Preferably, the absolute value of α - β is greater than the half-angle bandwidth Δθ of the holographic optical element II (510) 2 And is greater than half angle bandwidth delta theta of holographic optical element III (520) 3 I.e.
|α-β|>Δθ 2 ， (6)
|α-β|>Δθ 3 ， (7)
To avoid the light waves from creating image crosstalk on holographic optical element II (510) and holographic optical element III (520). Preferably, the voltage on-off of six subunits of the PDLC module (310) is controlled, and four voltage on states are total: state (1), voltages of PDLC-1 (311) and PDLC-3 (312) are on, voltages of the remaining PDLC subcells are off, and view 1 (801), view 3 (803), view 7 (807), and view 9 (809) are open; state (2), voltage of PDLC-2 (312) turned on, voltage of the remaining PDLC subcells turned off, and view 2 (802) and view 8 (808) are turned on; state (3), voltages of PDLC-4 (314) and PDLC-6 (316) are on, voltages of the rest of PDLC subcells are off, and view point 4 (804) and view point 6 (806) are opened; state (4), voltage of PDLC-5 (315) is on, voltage of the remaining PDLC subcells is off, and view 5 is opened (805). Under the four voltage conducting states, the view points are respectively opened at intervals, so that adjacent view points are not opened at the same time, and light crosstalk between the adjacent view points can be effectively avoided when the distance between the adjacent view points is smaller than that of the pupils of the human eyes.
According to the large eye box crosstalk-free holographic optical waveguide augmented reality display device, on one hand, 3 multiplied by 3 viewpoint array arrangement is generated through wavefront replication and diffraction of holographic optical elements, so that eye box expansion is realized; on the other hand, through the different voltage on states of the PDLC module, the time-sharing opening of the view points is realized, and the light crosstalk of the adjacent view points is effectively avoided.
Drawings
Fig. 1 is a schematic structural diagram of a large eye-box crosstalk-free holographic optical waveguide augmented reality display device.
Fig. 2 is a three-dimensional optical path diagram of parallel light passing through a wavefront replication module.
Fig. 3 is a PDLC module.
Fig. 4 is a schematic diagram of the composition of the subunits of the holographic optical element I.
Fig. 5 is a schematic diagram of the composition of subunits of holographic optical element II.
FIG. 6 is a schematic diagram of the composition of subunits III of a holographic optical element
Fig. 7 shows the positional relationship between the eye point formed by the hologram optical element II and the hologram optical element III and the human eye.
Fig. 8 is a view point formed by the hologram optical element II.
Fig. 9 is a view point formed by the hologram optical element III.
Fig. 10 is a schematic view of an exposure light path of the hologram optical element I.
Fig. 11 is a schematic diagram of an exposure light path of the hologram optical element II.
Fig. 12 is a schematic view of an exposure apparatus for the hologram optical element III.
Fig. 13 is a 3×3 viewpoint arrangement generated by the apparatus.
Fig. 14 is a view of the PDLC module in state (1) corresponding to open.
Fig. 15 is a view of the PDLC module in state (2) corresponding to open.
Fig. 16 is a view of the PDLC module in state (3) corresponding to open.
Fig. 17 is a view of the PDLC module in state (4) corresponding to open.
The graphic reference numerals in the above figures are: 100 projection module, 101 projector, 102 collimator lens, 200 wavefront replication module 210 vertical wavefront replication unit, 211 beam splitter I,212 mirror I,213 beam splitter II,214 mirror II,220 horizontal wavefront replication unit, 221 beam splitter III,222 mirror III,300 incoupling module, 310PDLC module, 311PDLC-1, 312PDLC-2, 313PDLC-3, 314PDLC-4, 315PDLC-5, 316PDLC-6, 320 hologramOptical element I,400 waveguide, 500 outcoupling module, 510 holographic optical element II,511 holographic optical element II 1, 512 holographic optical element II 2, 513 holographic optical element II 3, 514 holographic optical element II 4, 515 holographic optical element II 5, 516 holographic optical element II sub-area 6, 520 holographic optical element III,521 holographic optical element III sub-area 1, 522 holographic optical element III sub-area 2, 523 holographic optical element III sub-area 3, 600 human eyes, 700 plane light wave L,701 sub-plane light wave L 01 Sub-planar lightwave L of 702 02 703 sub-planar lightwave L 03 711 sub-planar lightwave L 11 Sub-planar lightwave L of 712 12 713 sub-planar lightwave L 13 714 sub-planar lightwave L 14 715 sub-planar lightwave L 15 716 sub-planar lightwaves L 16 An array of 800 viewpoints, 801 viewpoints 1, 802 viewpoints 2, 803 viewpoints 3, 804 viewpoints 4, 805 viewpoints 5, 806 viewpoints 6, 807 viewpoints 7, 808 viewpoints 8, 809 viewpoints 9,9 left side converging light axis, a rotation center of 10 human eyes, 11 trapezoidal prism I,12 trapezoidal prism II,13 holographic material I,14 refractive index matching liquid, 15 signal light of holographic material I, 16 holographic material I reference light I,17 holographic material I reference light II,18 isosceles diameter triangle prism, 19 convex lens, 20 holographic material II,21 holographic material II signal light, 22 holographic material II reference light, 23 holographic material III,24 holographic material III signal light, 25 holographic material III reference light. It should be understood that the above-described figures are merely schematic and are not drawn to scale.
Detailed Description
The present invention will be described in further detail with reference to an exemplary embodiment of a large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of the present invention. It is noted that the following examples are given for the purpose of illustration only and are not to be construed as limiting the scope of the invention, since numerous insubstantial modifications and adaptations of the invention will be within the scope of the invention as viewed by one skilled in the art from the foregoing disclosure.
The invention provides a large-eye-box crosstalk-free holographic optical waveguide augmented reality display device, which is shown in figure 1 and comprises a projection module (100), a wavefront replication module (200), an in-coupling module (300), a waveguide (400) and an out-coupling module (500). The projection module (100) comprises a projector (101) and a collimating lens (102), and has the functions of projecting an image source and collimating projected light waves. The wavefront replication module (200) comprises a vertical wavefront replication unit (210) and a horizontal wavefront replication unit (220). The wave front replication module (200) replicates the light waves output by the projection module (100) into six-beam planar light waves. The in-coupling module (300) comprises a polymer dispersed liquid crystal (polymer dispersed liquid crystal, PDLC) module (310) and a holographic optical element I (320), and the in-coupling module (300) couples six planar lightwaves generated by the wave front replication module (200) into the waveguide (400). The waveguide (400) provides a total reflection transmission path for the coupled-in light waves and has a good optical transmission for ambient light. The coupling-out module (500) comprises a holographic optical element II (510) and a holographic optical element III (520), the coupling-out module (500) couples and converges light waves in the waveguide (400) at a certain diffraction angle to form nine viewpoints which are distributed in a 3 multiplied by 3 mode, and the optical axis of each viewpoint is coincident with the visual axis of eyes at corresponding positions.
In the projection module (100), a projector (101) projects an image source to be displayed, and a collimator lens (102) collimates the projected light wave into a planar light wave L (700).
The wavefront replication module (200) comprises a vertical wavefront replication unit (210) and a horizontal wavefront replication unit (220). The vertical wavefront copying unit (210) further comprises a beam splitter I (211), a reflector I (212), a beam splitter II (213) and a reflector II (214), as shown in FIG. 2; the horizontal wavefront reproducing unit (220) further includes a beam splitter III (221) and a mirror III (222).
For convenience in describing the structure of the device, a three-dimensional coordinate system shown in fig. 1 is established, wherein the x-axis is the long axis direction of the waveguide, the z-axis is the short axis direction of the waveguide, the z-axis is the direction vertical to the paper surface, and the y-axis is the direction vertical to the waveguide surface.
The arrangement of the elements in the vertical wavefront copying unit (210) is shown in fig. 2, the beam splitting sheet I (211) forms 45 degrees with the z axis and the y axis, and the reflecting mirrorI (212) and the light splitting sheet I (211) are arranged in parallel along the z axis; the beam splitter II (213) forms an angle of 135 degrees with the y-axis, is perpendicular to the beam splitter I (211), and is positioned behind the beam splitter I (211) along the y-axis; the reflecting mirror II (214) and the light splitting sheet II (213) are arranged in parallel along the z axis. The light-splitting sheet I (211) and the light-splitting sheet II (213) have a certain proportion of reflection and transmission effects on incident light waves: the reflectance of the light-splitting sheet I (211) is 30% and the transmittance is 70%; the reflectance of the light-splitting sheet II (213) was 50%, and the transmittance was 50%. The intensity of the planar light wave L (700) output by the projection module is I, the reflected light intensity is 0.3I and the transmitted light intensity is 0.7I after passing through the light splitting sheet I (211), wherein the light wave reflected by the light splitting sheet I (211) propagates along the z-axis to reach the reflecting mirror I (212) and is further reflected to generate the sub-planar light wave L 03 (703) The light wave transmitted by the light-splitting sheet I (211) propagates in the original direction to reach the light-splitting sheet II (213). A part of the light wave reaching the light splitting sheet II (213) is reflected and a part of the light wave is transmitted, the reflected light intensity is 0.35I, and the transmitted light intensity is 0.35I, wherein the light wave reflected by the light splitting sheet II (213) propagates along the z-axis to reach the reflecting mirror II (214) and is further reflected to generate a sub-planar light wave L 01 (701) The light wave transmitted by the light-splitting sheet II (213) generates a sub-planar light wave L 02 (702). The planar light waves incident into the vertical wavefront copying unit (210) are copied into three planar light waves, i.e. sub-planar light waves L, which are shifted in the z-axis direction 01 (701) Light waves L in sub-plane 02 (702) Light waves L in sub-plane 03 (703)。
The arrangement of the elements in the horizontal wavefront copying unit (220) is shown in fig. 2, the beam splitter plate III (221) forms an included angle of 45 ° with the x-axis and the y-axis, and the reflecting mirror III (222) and the beam splitter plate III (221) are arranged in parallel along the x-axis. The light-splitting sheet III (221) has a certain proportion of reflectivity and transmittance to the incident light wave: the reflectance of the light-splitting sheet III (221) was 70% and the transmittance was 30%. Three sub-planar lightwaves L with a certain shift in the z-axis direction generated by a vertical wavefront copying unit 01 (701)、L 02 (702)、L 03 (703) Enters the horizontal wave front copying unit to reach the light splitting sheet III (221), the light wave reflected by the light splitting sheet III (221) propagates along the x-axis to reach the reflecting mirror III (222), and is further reflected to generate three sub-planar light waves, namely sub-planar light wave L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713). The sub-planar lightwave L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Has certain displacement along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L (700). The light waves transmitted by the beam-splitting sheet III (221) form three-beam replicated planar light waves, namely sub-planar light waves L 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716). The sub-planar lightwave L 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716) Has certain displacement along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L (700). The wavefront copying module (200) copies the planar light wave L (700) generated by the projection module to generate six groups of sub-planar light waves carrying the same image information, namely, the sub-planar light waves L, through two-stage wavefront modulation of the vertical wavefront copying unit and the horizontal wavefront copying unit 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Light waves L in sub-plane 14 (714) Light waves L in sub-plane 15 (715) Light waves L in sub-plane 16 (716) As shown in fig. 2. The six sets of sub-planar lightwaves are arranged in an xz plane in a 2 x 3 array. Wherein the plane light wave is L 11 (711) The light intensity of the light is 0.245I, and the light waves L are sub-planar 12 (712) The light intensity of the light is 0.245I, and the light waves L are sub-planar 13 (713) The light intensity of the light is 0.21I, and the light waves L are sub-planar 14 (714) The light intensity of the light is 0.105I, and the light waves L are sub-planar 15 (715) The light intensity of the light is 0.105I, and the light waves L are sub-planar 16 (716) Is 0.09I.
In the coupling-in module, the PDLC module (310) consists of six PDLC subunits, wherein each PDLC subunit has the same size, the length of 15mm and the width of 7.5mm, can transmit light under the condition of applying voltage and scatter light under the condition of not applying voltage. The arrangement of 6 PDLC subunits contained by the PDLC module (310) is shown in fig. 3 as being arranged in a 2 x 3 array in the xz-plane.
Six groups of sub-planar light waves generated by the wave front replication module (200) and six PDLC sub-units in the PDLC module (310)Incident in one-to-one correspondence, i.e. sub-planar lightwave L 11 (711) Incident PDLC-1 (311), sub-planar lightwave L 12 (712) Incident PDLC-2 (312), sub-planar lightwave L 13 (713) Incident PDLC-3 (313), sub-planar lightwave L 14 (714) Incident PDLC-4 (314), sub-planar lightwave L 15 (715) Incident PDLC-5 (315), sub-planar lightwave L 16 (716) Incident PDLC-6 (316).
As shown in fig. 4, the hologram optical element I (320) includes left and right sub-regions, and the left sub-region of the hologram optical element I (320) is 15mm long and 30mm wide, corresponding to the left three PDLC sub-units in the PDLC module (310), namely, PDLC-4 (314), PDLC-5 (315), and PDLC-6 (316). After passing through the PDLC module (310), the light wave is diffracted on the holographic optical element I (320) and propagates in the xy-plane in a direction at an angle β to the positive y-axis direction. The right sub-region of holographic optical element I (320) is 15mm long and 30mm wide, corresponding to the right three PDLC sub-cells in PDLC module (310), namely PDLC-1 (311), PDLC-2 (312), and PDLC-3 (313). After passing through the PDLC module (310), the light wave is diffracted on the holographic optical element I (320) and propagates in the xy-plane in a direction at an angle alpha to the y-axis. Both angles alpha and beta satisfy the total reflection condition of the waveguide (400).
The difference between α and β needs to be greater than the half-angle bandwidth Δθ of the holographic optical element II (510) 2 And is greater than half angle bandwidth delta theta of holographic optical element III (520) 3 I.e.
|α-β|>Δθ 2 ， (6)
|α-β|>Δθ 3 ， (7)
The light waves are prevented from generating image crosstalk on the holographic optical element II (510) and the holographic optical element III (520). In this embodiment, α takes a value of 45 °, and β takes a value of 60 °, which satisfies the above requirements.
The holographic optical element II (510) in the outcoupling module includes six sub-regions, as shown in fig. 5, namely, a holographic optical element II sub-region 1 (511), a holographic optical element II sub-region 2 (512), a holographic optical element II sub-region 3 (513), a holographic optical element II sub-region 4 (514), a holographic optical element II sub-region 5 (515) and a holographic optical element II sub-region 6 (516). Each holographic optical element II sub-region is the same size as the sub-cell of the PDLC module (310), 15mm long and 7.5mm wide. Three parallel light waves with the propagation angle alpha, which are diffracted out from the right side of the holographic optical element I (320), reach three sub-areas on the left side of the holographic optical element II (510) to be diffracted, so that three left viewpoints, namely a viewpoint 1 (801), a viewpoint 2 (802) and a viewpoint 3 (803), are generated. The undiffracted light intensity continues to totally reflect within the waveguide (400), propagates to the sub-areas 4, 5 to 6 of the holographic optical element II (510), and diffracts, creating three viewpoints on the right, viewpoint 7 (807), viewpoint 8 (808) and viewpoint 9 (809), the arrangement of viewpoints created by the holographic optical element II (510) being shown in fig. 8.
The holographic optical element III (520) comprises three sub-regions, as shown in fig. 6, holographic optical element III sub-region 1 (521), holographic optical element III sub-region 2 (522), and holographic optical element III sub-region 3 (523), respectively. Each holographic optical element III subarea has the same size as the subarea of the holographic optical element II, has a length of 15mm and a width of 7.5mm, and three subareas are arranged in a row in the same direction as the holographic optical element I (320) and the holographic optical element II (510) subareas. Three planar light waves with the propagation angle beta diffracted out of the left side of the holographic optical element I (320) respectively reach three sub-areas of the holographic optical element III (520) and are diffracted to generate three middle viewpoints, namely a viewpoint 4 (804), a viewpoint 5 (805) and a viewpoint 6 (806), and the viewpoint arrangement generated by the holographic optical element III (520) is shown in fig. 9.
The holographic optical element II (510) is bonded to the waveguide by an index matching fluid, and the holographic optical element III (520) is bonded to the holographic optical element II (510) by an index matching fluid. The light waves diffracted by the hologram optical element II (510) and the hologram optical element III (520) form a 3×3 viewpoint matrix, and the positional relationship of the respective viewpoints is shown in fig. 13.
Preferably, in order to make the images obtained by the human eye at the various viewpoints clearer, the images are imaged in the fovea of the retina of the human eye, the central points of the various viewpoints and the diffracted light waves thereof are arranged on the visual axis of the human eye, and particularly as shown in fig. 9, dh represents the distances between the left and right side viewpoints and the central viewpoint in the x-axis direction. The Dh is the number of the components,
Dh＝Rh×sinθ xy ， (2)
wherein Rh is the horizontal rotation radius of eyeball, θ xy The rotation angles of the eyes are corresponding to the left and right side viewpoints in the xy plane. Similarly, the distance Dv between the upper and lower side view points and the central view point in the z-axis direction is,
Dv＝Rv×sinθ yz ， (3)
wherein Rv is the vertical radius of rotation of the eyeball, θ yz The rotation angles of the eyes are corresponding to the viewpoints at the upper side and the lower side in the yz plane. The vertical distance Dv and the horizontal distance Dh between the eye viewpoints are both smaller than one time the pupil diameter of the eye and larger than half the pupil diameter of the eye.
Rotation θ in xy plane xy After the angle, the exit pupil distance change delta Erh of the left and right side view points is,
ΔErh＝Rh×(1-cosθ xy )， (4)
human eyes rotate theta in yz plane yz After the angle, the change amount delta Erv of the exit pupil distance of the view points at the upper side and the lower side is,
ΔErv＝Rv×(1-cosθ yz )， (5)
in this embodiment, rh=13 mm, rv=13 mm, θ xy =13.3° and θ yz =13.3°, and dh=3 mm, dv=3 mm, Δ Erh =0.3 mm, Δerfv=0.3 mm were calculated according to formulas (2) - (5).
The holographic optical element I (320) is a reflective volume holographic grating and is prepared by holographic exposure, and the exposure device comprises a trapezoidal prism I (11), a trapezoidal prism II (12), a holographic material I (13) and an index matching liquid (14). The angles of the trapezoid prism I (11) and the trapezoid prism II (12) are 45 degrees, and the refractive index is 1.5 the same as that of the optical waveguide. The two trapezoidal prisms are precisely attached to the two sides of the holographic material I (13) through the refractive index matching liquid (14). Wherein the holographic material I (13) has a length of 30mm and a width of 22.5mm.
The exposure process of the holographic material I (13) is shown in fig. 10. The signal light (14) is perpendicularly incident on the plane of the holographic material I (13). The reference light I (16) is incident on the left side of the holographic material I (13) at α through the hypotenuse of the trapezoidal prism I (11). The reference light II (17) is incident on the right side of the surface of the holographic material I (13) at β through the hypotenuse of the trapezoidal prism I (11).
The holographic optical element II (510) is a reflective volume holographic grating and is prepared by holographic exposure, and the exposure device comprises a holographic material II (20), an isosceles right prism (18), a convex lens (19) and an index matching liquid (14). The isosceles right prism (18) has a refractive index equal to that of the waveguide (400) of 1.5. The isosceles right prism (18) is precisely attached to the holographic material II (20) through the refractive index matching liquid (14), wherein the effective exposure area of the holographic material II (20) is 30mm long and 22.5mm wide.
In the exposure process of the holographic material II (20), as shown in fig. 11, the exposure area of the holographic material II (20) is divided into six sub-areas, the division mode is the same as that of the sub-areas of the holographic optical element II (510), the six sub-areas of the holographic material II (20) are exposed one by one, each time one sub-area is exposed, the signal light (21) is incident on the surface of the holographic material II (20) through the oblique side of the isosceles right prism (18) in alpha, and the reference light (22) of the holographic material II is incident on the surface of the holographic material II (20) through the lens.
The holographic optical element III (520) is a reflective volume holographic grating and is prepared by holographic exposure, and the exposure device comprises an isosceles right prism (18), a convex lens (19), a holographic material III (23) and an index matching liquid (14). The isosceles right prism (18) is precisely attached to the surface of the holographic material III (23) through the matching liquid (14), and the effective exposure area of the holographic material III (23) is 15mm long and 22.5mm wide.
In the exposure process of the holographic material III (23), as shown in fig. 12, the exposure area of the holographic material III (25) is divided into three sub-areas, the division mode is the same as that of the sub-areas of the holographic optical element III (520), the three sub-areas of the holographic material III (25) are exposed one by one, each time one sub-area is exposed, the signal light (24) is incident on the surface of the holographic material III (23) in beta through the isosceles right prism (18), and the reference light (25) of the holographic material III is incident on the surface of the holographic material III (23) after passing through the convex lens (19).
The working principle of the large-eye-box crosstalk-free holographic optical waveguide augmented reality display device is as shown in fig. 1, the projector (101) projects divergent spherical light waves containing image information, and the collimating lens (102) collimates the divergent spherical light waves into planar light waves containing original image information; the planar light wave (700) is transmitted to the wave front replication unit (200), and is subjected to two-stage wave front replication by the vertical wave front replication unit (210) and the horizontal wave front replication unit (220) to generate six beams of planar light waves containing the same image information, namely sub-planar light waves L 11 (711) Light waves L in sub-plane 12 (712) Light waves L in sub-plane 13 (713) Light waves L in sub-plane 14 (714) Light waves L in sub-plane 15 (715) Sub-planar lightwave L 16 (716) The method comprises the steps of carrying out a first treatment on the surface of the When the light wave passes through the PDLC and reaches the right area of the holographic optical element I (320), the holographic optical element I (320) diffracts the light wave to the alpha direction, the light wave is transmitted to the left side of the holographic optical element II (510) at the decoupling module through the waveguide (400), at the moment, part of the light wave is diffracted into convergent light at the left side of the holographic optical element II (510), the rest of the planar light wave is continuously totally reflected to the right side of the holographic optical element II (510), at the moment, the right side of the holographic optical element II (11) diffracts the incident light wave into convergent light; when the light wave passes through the PDLC to the left of the holographic optical element I (320), the holographic optical element I (320) diffracts it in the β direction, and the light wave passes through the waveguide (400) to reach the middle region of the holographic optical element II (510) at the outcoupling module. Since the Bragg condition corresponding to the holographic optical element II (510) is not satisfied, the light wave is transmitted through the holographic optical element II (510) to reach the surface of the holographic optical element III (520), the Bragg condition corresponding to the holographic optical element III (520) is satisfied, and the light wave is diffracted into convergent light; nine converging light beams are formed at the decoupling position, the nine converging light beams respectively form a view point 1 (801), a view point 2 (802), a view point 3 (803), a view point 4 (804), a view point 5 (805), a view point 6 (806), a view point 7 (807), a view point 8 (808) and a view point 9 (809), a 3×3 view point array is formed, and the human eyes watch the same image information at the nine view points, so that the expansion of the eye box is realized.
Preferably, the voltage on-off of six sub-areas of the PDLC module (310) is controlled, and four voltage on states are total: state (1), voltages of PDLC-1 (311) and PDLC-3 (312) are on, voltages of the remaining PDLC subcells are off, and view 1 (801), view 3 (803), view 7 (807), and view 9 (809) are open; state (2), voltage of PDLC-2 (312) turned on, voltage of the remaining PDLC subcells turned off, and view 2 (802) and view 8 (808) are turned on; state (3), voltages of PDLC-4 (314) and PDLC-6 (316) are on, voltages of the rest of PDLC subcells are off, and view point 4 (804) and view point 6 (806) are opened; state (4), voltage of PDLC-5 (315) is on, voltage of the remaining PDLC subcells is off, and view 5 is opened (805). Under the four voltage conducting states, the view points are respectively opened at intervals, so that adjacent view points are not opened at the same time, and light crosstalk between the adjacent view points can be effectively avoided when the distance between the adjacent view points is smaller than that of the pupils of the human eyes.
According to the large eye box crosstalk-free holographic optical waveguide augmented reality display device, on one hand, 3 multiplied by 3 viewpoint array arrangement is generated through wavefront replication and diffraction of holographic optical elements, so that eye box expansion is realized; on the other hand, through the different voltage on states of the PDLC module, the time-sharing opening of the view points is realized, and the light crosstalk of the adjacent view points is effectively avoided.
Claims (8)
1. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device is characterized by comprising a projection module, a wavefront replication module, an in-coupling module, a waveguide and an out-coupling module; the projection module comprises a projector and a collimating lens, and has the functions of projecting an image source and collimating projected light waves; the wave front replication module comprises a vertical wave front replication unit and a horizontal wave front replication unit, and the wave front replication module replicates the light waves output by the projection module into six-beam planar light waves; the in-coupling module comprises a polymer dispersed liquid crystal (polymer dispersed liquid crystal, PDLC) module and a holographic optical element I, and couples six planar lightwaves generated by the wave front replication module (200) into a waveguide; the waveguide provides a total reflection transmission channel for the coupled light waves, and has better optical transmittance for ambient light; the coupling-out module comprises a holographic optical element II and a holographic optical element III, the coupling-out module couples and converges light waves in the waveguide at a certain diffraction angle to form nine viewpoints which are distributed in a 3 multiplied by 3 mode, and the optical axis of each viewpoint is coincident with the visual axis of eyes at corresponding positions.
2. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of claim 1, wherein in the projection module the projector projects an image source to be displayed, and the collimating lens collimates the projected light wave into a planar light wave L.
3. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of claim 1, wherein the wavefront replication module comprises a vertical wavefront replication unit and a horizontal wavefront replication unit; the vertical wavefront copying unit comprises a light splitting sheet I, a reflecting mirror I, a light splitting sheet II and a reflecting mirror II; the horizontal wave front copying unit comprises a light splitting sheet III and a reflecting mirror III; establishing a three-dimensional coordinate system, wherein an x-axis is the long axis direction of the waveguide, a z-axis is the short axis direction of the waveguide, the z-axis is the direction vertical to the paper surface, and the y-axis is the direction vertical to the waveguide surface; in the vertical wavefront copying unit, a beam splitting sheet I forms 45 degrees with a z axis and a y axis, and a reflecting mirror I and the beam splitting sheet I are arranged in parallel along the z axis; the beam splitter II forms an angle of 135 degrees with the y-axis, is perpendicular to the beam splitter I and is positioned behind the beam splitter I along the y-axis; the reflecting mirror II and the light splitting sheet II are arranged in parallel along the z axis; the light-splitting sheet I and the light-splitting sheet II have certain proportion of reflection and transmission effects on incident light waves: the reflectivity of the light-splitting sheet I is R I Transmittance T I The method comprises the steps of carrying out a first treatment on the surface of the The reflectance of the light-splitting sheet II (213) is R II Transmittance T II The method comprises the steps of carrying out a first treatment on the surface of the The intensity of the planar light wave L output by the projection module is I, and the reflected light intensity is I multiplied by R after passing through the light splitting sheet I I The transmitted light intensity is I×T I Wherein the light wave reflected by the beam splitter I propagates along the z-axis to the reflector I and is further reflected to generate a sub-planar light wave L 03 The light wave transmitted by the light-splitting sheet I propagates along the original direction to reach the light-splitting sheet II; the light wave reaching the light-splitting sheet II is partially reflected and partially transmitted, and is reflectedThe light intensity is I×T I ×R II The transmitted light intensity is I×T I ×T II Wherein the light wave reflected by the beam splitter II propagates along the z-axis to reach the reflector II, and is further reflected to generate a sub-planar light wave L 01 The light wave transmitted by the light-splitting sheet II generates a sub-planar light wave L 02 The method comprises the steps of carrying out a first treatment on the surface of the The planar light wave incident into the vertical wavefront copying unit is copied into three planar light waves, i.e. sub-planar light waves L, which are shifted in the z-axis direction 01 Light waves L in sub-plane 02 Light waves L in sub-plane 03 The method comprises the steps of carrying out a first treatment on the surface of the In the horizontal wave front copying unit, a beam splitting sheet III forms an included angle of 45 degrees with an x axis and a y axis, and a reflecting mirror III and the beam splitting sheet III are arranged in parallel along the x axis; the light-splitting sheet III has a certain proportion of reflectivity and transmittance to incident light waves: the reflectance of the light-splitting sheet III is R III Transmittance T III The method comprises the steps of carrying out a first treatment on the surface of the Three sub-planar lightwaves L with a certain shift in the z-axis direction generated by the vertical wavefront copying unit 01 、L 02 、L 03 Enters the horizontal wave front replication unit to reach the light splitting sheet III, light waves reflected by the light splitting sheet III propagate along the x-axis to reach the reflecting mirror III, and are further reflected to generate three sub-planar light waves, namely sub-planar light waves L 11 Light waves L in sub-plane 12 Light waves L in sub-plane 13 The method comprises the steps of carrying out a first treatment on the surface of the The sub-planar lightwave L 11 Light waves L in sub-plane 12 Light waves L in sub-plane 13 Certain displacement is arranged along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L; the light waves transmitted by the beam-splitting sheet III form three-beam replicated planar light waves, namely sub-planar light waves L 14 Light waves L in sub-plane 15 Light waves L in sub-plane 16 The method comprises the steps of carrying out a first treatment on the surface of the The sub-planar lightwave L 14 Light waves L in sub-plane 15 Light waves L in sub-plane 16 Has certain displacement along the z-axis direction, and the propagation directions of the three are the same as the propagation direction of the planar lightwave L.
4. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of claim 1, wherein in the in-coupling module, the PDLC module is composed of six PDLC subunits, wherein each PDLC subunit is the same size, has a length d and a width w,light can be transmitted under the condition of voltage application, and light can be scattered under the condition of no voltage application; the PDLC module comprises 6 PDLC subunits which are arranged in an xz plane in a 2 x 3 array; the six groups of sub-planar light waves generated by the wave front replication module are incident in one-to-one correspondence with the six PDLC subunits in the PDLC module, namely the sub-planar light waves L 11 Incident PDLC-1, sub-planar lightwave L 12 Incident PDLC-2, sub-planar lightwave L 13 Incident PDLC-3, sub-planar lightwave L 14 Incident PDLC-4, sub-planar lightwave L 15 Incident PDLC-5, sub-planar lightwave L 16 Incident PDLC-6; the holographic optical element I comprises a left sub-area and a right sub-area, the left sub-area of the holographic optical element I is long d and wide 3w, and the left sub-areas correspond to three PDLC sub-units on the left side in the PDLC module, namely PDLC-4, PDLC-5 and PDLC-6; when the sub-planar light wave passes through the PDLC module, the sub-planar light wave is diffracted on the holographic optical element I and propagates in the xy plane in the direction forming an angle beta with the positive direction of the y axis; the right side subarea of the holographic optical element I is long d and wide 3w, and corresponds to three PDLC subunits on the right side in the PDLC module, namely PDLC-1, PDLC-2 and PDLC-3; after passing through the PDLC module, the light wave is diffracted on the holographic optical element I, propagating in the xy-plane in a direction at an angle α to the y-axis; the included angles alpha and beta both meet the total reflection condition of the waveguide; the absolute value of the alpha-beta is larger than the half angle bandwidth delta theta of the holographic optical element II 2 And is larger than the half angle bandwidth delta theta of the holographic optical element III 3 The method comprises the steps of carrying out a first treatment on the surface of the I.e. |alpha-beta|>Δθ 2 ，|α-β|>Δθ 3 To avoid the light waves from creating image crosstalk on the holographic optical elements II and III.
5. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device according to claim 1, characterized in that the holographic optical element II in the outcoupling module comprises six sub-areas in total, namely holographic optical element II sub-area 1, holographic optical element II sub-area 2, holographic optical element II sub-area 3, holographic optical element II sub-area 4, holographic optical element II sub-area 5 and holographic optical element II sub-area 6; each holographic optical element II subarea has the same size as the subunits of the PDLC moduleThe length is d, and the width is w; wherein three parallel light waves with the propagation angle alpha diffracted on the right side of the holographic optical element I respectively reach three sub-areas on the left side of the holographic optical element II to be diffracted, and the diffraction efficiency is eta left Three views on the left side, namely view 1, view 2 and view 3, are generated; the undiffracted light continues to totally reflect in the waveguide, propagates to the subregions 4, 5 to 6 of the holographic optical element II and diffracts with a diffraction efficiency eta right Three views on the right side, namely view 7, view 8 and view 9, are generated; the holographic optical element III comprises three sub-areas which are respectively a holographic optical element III sub-area 1, a holographic optical element III sub-area 2 and a holographic optical element III sub-area 3; the size of each subarea of the holographic optical element III is the same as that of the subarea of the holographic optical element II, the length is d, the width is w, and the three subareas are arranged in a row, and the direction of the row is the same as that of the subareas of the holographic optical element I and the holographic optical element II; three planar light waves with the propagation angle beta diffracted out from the left side of the holographic optical element I respectively reach three sub-areas of the holographic optical element III, and diffraction occurs, and the diffraction efficiency is eta center Generating three intermediate viewpoints, namely viewpoint 4, viewpoint 5 and viewpoint 6; the holographic optical element II is bonded with the waveguide through the refractive index matching liquid, and the holographic optical element III is bonded with the holographic optical element II through the refractive index matching liquid; the light waves diffracted by the holographic optical elements II and III form a 3×3 viewpoint matrix.
6. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of claim 1, wherein the projector projects divergent spherical light waves containing image information, the collimating lens collimates the divergent spherical light waves into planar light waves containing original image information; the planar light wave is transmitted to the wave front replication unit, and six planar light waves containing the same image information, namely sub-planar light wave L, are generated through two-stage wave front replication of the vertical wave front replication unit and the horizontal wave front replication unit 11 Light waves L in sub-plane 12 Light waves L in sub-plane 13 Light waves L in sub-plane 14 Planar lightwaveL 15 Sub-planar lightwave L 16 The method comprises the steps of carrying out a first treatment on the surface of the When light waves penetrate PDLC to reach the right area of the holographic optical element I, the holographic optical element I diffracts the light waves to the alpha direction, the light waves are transmitted to the left side of the holographic optical element II at the position of the decoupling module through the waveguide, at the moment, part of the light waves are diffracted into convergent light at the left side of the holographic optical element II, the rest of the planar light waves continue to be totally reflected to the right side of the holographic optical element II, at the moment, the right side of the holographic optical element II diffracts the incident light waves into convergent light; when light waves penetrate PDLC to the left side of the holographic optical element I, the holographic optical element I diffracts the light waves to the beta direction, and the light waves reach the middle area of the holographic optical element II at the position of the decoupling module through the transmission of the waveguide, and as the Bragg condition corresponding to the holographic optical element II is not met, the light waves penetrate through the holographic optical element II to reach the surface of the holographic optical element III, the Bragg condition corresponding to the holographic optical element III is met, and the light waves are diffracted into convergent light; nine converging light beams are formed at the decoupling position, the nine converging light beams respectively form a view point 1, a view point 2, a view point 3, a view point 4, a view point 5, a view point 6, a view point 7, a view point 8 and a view point 9, a 3×3 view point array is formed, and the human eyes watch the same image information at the nine view points, so that the expansion of the eye box is realized.
7. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device of claim 1, wherein voltage on-off of six subunits of the PDLC module is controlled, for a total of four voltage on-states: state (1), voltage of PDLC-1 and PDLC-3 is conducted, voltage of other PDLC sub-units is closed, and view point 1, view point 3, view point 7 and view point 9 are opened; state (2), voltage of PDLC-2 is conducted, voltage of other PDLC sub-units is closed, and view point 2 and view point 8 are opened; state (3), the voltages of PDLC-4 and PDLC-6 are conducted, the voltages of the rest PDLC subunits are closed, and view point 4 and view point 6 are opened; a state (4) in which the voltage of the PDLC-5 is turned on, the voltages of the rest PDLC subcells are turned off, and the viewpoint 5 is opened; under the four voltage conducting states, the view points are respectively opened at intervals, so that adjacent view points are not opened at the same time, and light crosstalk between the adjacent view points can be effectively avoided when the distance between the adjacent view points is smaller than that of the pupils of the human eyes.
8. The large-eye-box crosstalk-free holographic optical waveguide augmented reality display device according to claim 1, characterized in that it realizes eye-box expansion by generating 3 x 3 viewpoint array arrangement through wavefront replication and holographic optical element diffraction on the one hand; on the other hand, through the different voltage on states of the PDLC module, the time-sharing opening of the view points is realized, and the light crosstalk of the adjacent view points is effectively avoided.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311284667.4A CN117539059A (en) | 2023-10-07 | 2023-10-07 | Large eye box crosstalk-free holographic optical waveguide augmented reality display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311284667.4A CN117539059A (en) | 2023-10-07 | 2023-10-07 | Large eye box crosstalk-free holographic optical waveguide augmented reality display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117539059A true CN117539059A (en) | 2024-02-09 |
Family
ID=89788759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311284667.4A Pending CN117539059A (en) | 2023-10-07 | 2023-10-07 | Large eye box crosstalk-free holographic optical waveguide augmented reality display device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117539059A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104656259A (en) * | 2015-02-05 | 2015-05-27 | 上海理湃光晶技术有限公司 | Conjugated narrow-band tri-phosphor staggered volume holographic grating waveguide near-to-eye optical display device |
| WO2023068456A1 (en) * | 2021-10-22 | 2023-04-27 | 인하대학교 산학협력단 | Waveguide-type see-through maxwellian near-to-eye display having eyebox enlarged using pin mirror holographic optical element array |
| KR20230085043A (en) * | 2021-12-06 | 2023-06-13 | 고려대학교 세종산학협력단 | Super multi-view augmented reality display for 3d object representation, and operating method of the same |
| CN116381949A (en) * | 2023-05-31 | 2023-07-04 | 杭州光粒科技有限公司 | Display module |
| CN116699837A (en) * | 2022-03-04 | 2023-09-05 | 恩维世科斯有限公司 | Light engine |
| CN219657952U (en) * | 2023-04-13 | 2023-09-08 | 合肥英睿系统技术有限公司 | Two-dimensional pupil expansion module and optical display system |
-
2023
- 2023-10-07 CN CN202311284667.4A patent/CN117539059A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104656259A (en) * | 2015-02-05 | 2015-05-27 | 上海理湃光晶技术有限公司 | Conjugated narrow-band tri-phosphor staggered volume holographic grating waveguide near-to-eye optical display device |
| WO2023068456A1 (en) * | 2021-10-22 | 2023-04-27 | 인하대학교 산학협력단 | Waveguide-type see-through maxwellian near-to-eye display having eyebox enlarged using pin mirror holographic optical element array |
| KR20230085043A (en) * | 2021-12-06 | 2023-06-13 | 고려대학교 세종산학협력단 | Super multi-view augmented reality display for 3d object representation, and operating method of the same |
| CN116699837A (en) * | 2022-03-04 | 2023-09-05 | 恩维世科斯有限公司 | Light engine |
| CN219657952U (en) * | 2023-04-13 | 2023-09-08 | 合肥英睿系统技术有限公司 | Two-dimensional pupil expansion module and optical display system |
| CN116381949A (en) * | 2023-05-31 | 2023-07-04 | 杭州光粒科技有限公司 | Display module |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6736695B2 (en) | Waveguide structure | |
| JP6867999B2 (en) | Imaging light guide with reflective conversion array | |
| JP6720315B2 (en) | Imaging light guide with reflective conversion array | |
| CA2456907C (en) | Flat-panel projection display | |
| US20200341280A1 (en) | Waveguide image combiners for augmented reality displays | |
| JP2021528688A (en) | Waveguide rotary grid design for optimum efficiency | |
| CN107015368A (en) | A kind of nearly eye binocular display devices | |
| TWI785677B (en) | Near-eye image projection system and wearable device comprising said near-eye image projection system | |
| US20230213770A1 (en) | Image light guide with zoned diffractive optic | |
| CN114355502B (en) | Diffraction grating waveguide and AR display device | |
| US11853006B2 (en) | Light engine | |
| CN113325505A (en) | Optical waveguide lens and three-dimensional display device | |
| CN217443725U (en) | Optical-mechanical system | |
| CN117930423A (en) | Light guide device, light guide assembly and display device | |
| CN218675520U (en) | Waveguide-based holographic imaging system and electronic display device | |
| CN117539059A (en) | Large eye box crosstalk-free holographic optical waveguide augmented reality display device | |
| EP4050401A1 (en) | Optical system and mixed reality device | |
| CN214846067U (en) | Grating waveguide element and near-to-eye display equipment | |
| JP3483274B2 (en) | Image display device | |
| US20230367115A1 (en) | Compact head-up display and waveguide therefor | |
| CN219737894U (en) | Optical waveguide display device for increasing field angle and AR display equipment | |
| JP7508514B2 (en) | Compact Head-Up Display | |
| CN219625814U (en) | Head-up display module assembly and vehicle | |
| GB2616306A (en) | System and device | |
| CN116609947A (en) | Holographic display system with large eye movement range |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |