CN116400499A - Full-color waveguide display structure and head-mounted display device - Google Patents
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Abstract
The application discloses a full-color waveguide display structure and a head-mounted display device. The full-color waveguide display structure includes: a first waveguide body for propagating a first light source and a second light source; a first polarization grating and a second polarization grating as coupling means of the first waveguide body; the first polarization grating and the second polarization grating are respectively responsive to different polarized light; the second waveguide body is positioned at one side of the first waveguide body and is used for transmitting a third light source; and the third polarization grating is used as a coupling device of the second waveguide body.
Description
Technical Field
The present application relates to the field of optical technology, and more particularly, to a full-color waveguide display structure and a head-mounted display device.
Background
Optical waveguide display is one of transparent display technologies, and has higher light transmittance and more excellent display effect than other transparent display devices.
The existing optical waveguide display often comprises three gratings R+G+B, wherein the three gratings R+G+B are matched with three optical waveguides, so that the optical waveguide display structure becomes relatively heavy, compact and portable. The RGB three-color gratings are integrated into one piece, so that the RGB three-color gratings only need to be matched with one piece of optical waveguide, and the picture displayed by the optical waveguide display structure can have serious color cast.
Disclosure of Invention
An object of the present invention is to provide a full-color waveguide display structure and a new technical solution of a head-mounted display device, so as to solve at least one technical problem set forth in the background art.
According to a first aspect of the present application, a full color waveguide display structure is provided. The full-color waveguide display structure includes:
a first waveguide body for propagating a first light source and a second light source;
a first polarization grating and a second polarization grating as coupling means of the first waveguide body; the first polarization grating and the second polarization grating are respectively responsive to polarized light of different polarization states;
the second waveguide body is positioned at one side of the first waveguide body and is used for transmitting a third light source;
and the third polarization grating is used as a coupling device of the second waveguide body.
Optionally, the first waveguide body includes a first light incident surface and a first light emergent surface;
the first polarization grating includes a first in-coupling polarization grating;
the second polarization grating includes a second in-coupling polarization grating;
the third polarization grating includes a third in-coupling polarization grating;
the first and second in-coupling polarization gratings are disposed between the first and second waveguide bodies, and the third in-coupling polarization grating is disposed on a side of the second waveguide body away from the first waveguide body.
Optionally, the first polarization grating comprises a first out-coupling polarization grating;
the second polarization grating includes a second out-coupling polarization grating;
the third polarization grating includes a third out-coupling polarization grating;
the first and second out-coupling polarization gratings are disposed on a side of the first waveguide body away from the second waveguide body, and the third out-coupling polarization grating is disposed between the first and second waveguide bodies.
Optionally, the first polarization grating and the second polarization grating are respectively prepared from cholesteric liquid crystals with opposite optical rotation.
Optionally, the third polarization grating and the first polarization grating are respectively prepared from cholesteric liquid crystals with the same optical rotation.
Optionally, the first polarization grating, the third polarization grating and the second polarization grating are all reflective polarization gratings.
Optionally, the first light source and the third light source are light with first circular polarization states and different wavelengths, and the second light source is light with second circular polarization states;
the first light source is reflected by the first polarization grating after incidence and propagates in the first waveguide body;
the second light source is reflected by the second polarization grating after being incident and propagates in the first waveguide body;
the third light source is transmitted by the first polarization grating and the second polarization grating after being incident, reflected by the third polarization grating and propagates in the second waveguide body.
Optionally, the period of the first polarization grating is 360-370nm, and the Bragg period is 160-165nm;
the period of the second polarization grating is 410-420nm, and the Bragg period is 185-190nm;
the period of the third polarization grating is 490-500nm, and the Bragg period is 220-225nm.
Optionally, the first waveguide body and the second waveguide body are both transparent flat structures.
Optionally, the full color waveguide display structure has a field angle in the range of 30 ° -45 °.
According to a second aspect of embodiments of the present application, a head mounted display device is provided. The head mounted display device comprises the full color waveguide display structure of the first aspect.
According to one embodiment of the present application, a full-color waveguide display structure is provided. The full-color waveguide display structure includes a first waveguide body, first and second polarization gratings corresponding to the first waveguide body, a second waveguide body, and a third polarization grating corresponding to the second waveguide body. The embodiment of the application can eliminate the influence of color cast and ensure the effect of displaying imaging. On the other hand, the first polarization grating and the second polarization grating correspond to one first waveguide body, so that the full-color waveguide display structure is more compact and lighter.
Other features of the present application and its advantages will become apparent from the following detailed description of exemplary embodiments of the present application, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.
Fig. 1 is a schematic diagram of a reflective polarization grating in the present application.
Fig. 2 is a schematic structural diagram of a full-color waveguide display structure in an embodiment of the present application.
Reference numerals illustrate:
1. a first waveguide body; 11. a first light incident surface; 12. a first light-emitting surface;
2. a second waveguide body; 21. a second light incident surface; 22. a second light-emitting surface;
3. a first polarization grating; 31. a first incoupling polarization grating; 32. a first out-coupling polarization grating;
4. a second polarization grating; 41. a second in-coupling polarization grating; 42. a second out-coupling polarization grating;
5. a third polarization grating; 51. a third in-coupling polarization grating; 52. and third coupling out the polarization grating.
Detailed Description
Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.
The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
According to a first aspect of embodiments of the present application, a full-color waveguide display structure is provided. Referring to fig. 1-2, a full-color waveguide display structure includes:
a first waveguide body 1, said first waveguide body 1 being for propagating a first light source and a second light source.
A first polarization grating 3 and a second polarization grating 4, the first polarization grating 3 and the second polarization grating 4 being coupling means of the first waveguide body 1; the first polarization grating 3 and the second polarization grating 4 are respectively responsive to polarized light of different polarization states.
A second waveguide body 2, the second waveguide body 2 being located below the first waveguide body 1, the second waveguide body 2 being for propagating a third light source.
A third polarization grating 5, said third polarization grating 5 acting as coupling means for said second waveguide body 2.
In the embodiment of the application, the full-color waveguide display structure utilizes the unique polarization characteristic of a polarizer grating (PVG) (selective light splitting is realized based on the polarization state of incident light), so that the first light source and the second light source share one waveguide body, and further full-color waveguide display is realized through the combination of two waveguide bodies (blue-green+red or red-green+blue).
In this embodiment, the first waveguide body 1 is used for propagating a first light source and a second light source. I.e. the first light source and the second light source share a piece of the first waveguide body 1. The full-color waveguide display structure in the prior art needs to adopt three waveguides to realize image display. Compared with the prior art, the implementation makes the structure of the full-color optical waveguide more compact and portable.
In this embodiment, the first polarization grating 3 (e.g. B-PVG) and the second polarization grating 4 (e.g. G-PVG) together act as coupling means for the first waveguide body 1. The first polarization grating 3 and the second polarization grating 4 are respectively responsive to polarized light of different polarization states. Namely, the present embodiment employs the first polarization grating 3 and the second polarization grating 4 having different polarization responses. I.e. the first polarization grating 3 and the second polarization grating 4 respond differently to incident light of different polarization states.
For example, in one embodiment, the first polarization grating 3 has a modulating effect on right-hand circular polarization (RCP) incident light and the second polarization grating 4 has a modulating effect on left-hand circular polarization (LCP) incident light. Or in another embodiment, the first polarization grating 3 has a modulating effect on the left-hand circular polarization (LCP) incident light, and the second polarization grating 4 has a modulating effect on the right-hand circular polarization (RCP) incident light.
In this embodiment, the first light source and the second light source have different polarization states, since the first polarization grating 3 and the second polarization grating 4 are respectively responsive to polarized light of different polarization states. For example, the first light source has a first polarization state and the second light source has a second polarization state.
The first polarization grating 3 is capable of diffracting a first light source having a first polarization state into the first waveguide body 1; the second polarization grating 4 is capable of diffracting a second light source having a second polarization state into the first waveguide body 1.
A first light source, for example of a first polarization state, and a second light source of a second polarization state, pass perpendicularly through the first waveguide body 1 and are diffracted into the first waveguide body 1 by a first polarization grating 3 and a second polarization grating 4, respectively, as incoupling means; in the first waveguide body 1, the first light source and the second light source propagate in a total reflection form to the coupling-out area of the first waveguide body 1, and when reaching the coupling-out area of the first waveguide body 1, the first polarization grating 3 and the second polarization grating 4 serving as the coupling-out devices output emergent parallel light and finally enter the human eyes.
In this embodiment, the optical design of orthogonal polarization states is adopted in the input light (the second light source and the first light source) with adjacent wavelengths, so that the crosstalk problem of light in the waveguide can be greatly reduced.
In the full-color waveguide display structure of the prior art, a first light source and a second light source multiplex one polarization grating. Because the wavelengths of the first light source and the second light source are different, the deflection angles of the wavelengths of the first light source and the second light source to the same polarization grating are different, when the first light source and the second light source multiplex one polarization grating, paths of the first light source and the second light source which travel in the same waveguide are different, and a certain chromatic aberration is generated between the first light source and the second light source during imaging. In the embodiment of the application, the first light source with the first polarization state and the second light source with the second polarization state correspond to one piece of polarization grating (PVG), so that the first light source and the second light source can have the same deflection angle, the same propagation path is realized, and the problem of chromatic aberration is avoided.
In this embodiment the full colour waveguide display structure comprises a second waveguide body 2. The second waveguide body 2 is used for propagating a third light source. The third polarization grating 5, e.g. an R-PVG, acts as coupling means for the second waveguide body 2. A third light source, for example having a polarization state, passes perpendicularly through the second waveguide body 2 and is diffracted into said second waveguide body 2 by a third polarization grating 5 as an incoupling means; in the second waveguide body 2, the third light source propagates to the other end of the second waveguide body 2 in a form of total reflection, and when reaching the other end of the second waveguide body 2, the third polarization grating 5 serving as an outcoupling device outputs outgoing parallel light, and finally enters the human eye.
In this embodiment, the second waveguide body 2 is located on one side of the first waveguide body 1, and the full-color waveguide display structure is made more compact and lightweight while ensuring the display imaging effect. Referring to fig. 2, in the thickness direction of the first waveguide body 1, the first waveguide body 1 and the second waveguide body 2 are disposed opposite to each other.
The embodiment of the application provides a full-color waveguide display structure. The full-color waveguide display structure includes a first waveguide body 1, first and second polarization gratings 3 and 4 corresponding to the first waveguide body 1, a second waveguide body 2, and a third polarization grating 5 corresponding to the second waveguide body 2. The embodiment of the application can eliminate the influence of color cast and ensure the effect of displaying imaging. On the other hand, the first polarization grating 3 and the second polarization grating 4 correspond to one first waveguide body 1, so that the full-color waveguide display structure is more compact and lighter.
In one embodiment, referring to fig. 2, the first polarization grating 3 comprises a first incoupling polarization grating 31. The second polarization grating 4 comprises a second incoupling polarization grating 41. The third polarization grating 5 comprises a third in-coupling polarization grating 51.
The first and second in-coupling polarization gratings 31 and 41 are disposed between the first and second waveguide bodies 1 and 2, and the third in-coupling polarization grating 51 is disposed on a side of the second waveguide body 2 away from the first waveguide body 1.
In this embodiment, the first 31 and second 41 incoupled polarization gratings act as incoupler means for the first waveguide body 1. The third incoupling polarization grating 51 acts as incoupling means for the second waveguide body 2.
A first light source having a first polarization state is diffraction-coupled into the first waveguide body 1 via a first incoupling polarization grating 31. A second light source having a second polarization state is diffraction-coupled into the first waveguide body 1 via a second incoupling polarization grating 41.
The first and second in-coupling polarization gratings 31 and 41 are located in the in-coupling region of the first light-emitting surface 12 of the first waveguide body 1, and the first and second in-coupling polarization gratings 31 and 41 are juxtaposed in the thickness direction of the first waveguide body 1. Referring to fig. 2, the first in-coupling polarization grating 31 is disposed closer to the first light exit surface 12 than the second in-coupling polarization grating 41. Or the first incoupling polarization grating 31 is arranged further from the first light exit surface 12 than the second incoupling polarization grating 41.
The present embodiment is described with the first in-coupling polarization grating 31 disposed closer to the first light-emitting surface 12 than the second in-coupling polarization grating 41. For example, a first light source having a first polarization state enters the first waveguide body 1 vertically and is coupled into the first waveguide body 1 via a first coupling-in polarization grating 31; the second light source with the second polarization state enters the first waveguide body 1 vertically and the first incoupling polarization grating 31 (because the first incoupling polarization grating 31 does not have a modulating effect on the second light source with the second polarization state), and is diffracted into the first waveguide body 1 by the second incoupling polarization grating 41.
In this embodiment, the third incoupled polarization grating 51 acts as incoupler for the second waveguide body 2. The third coupling-in polarization grating 51 is located in the coupling-in region of the second light-emitting surface 22 of the second waveguide body 2. A third light source having a polarization state is transmitted through the first polarization grating 3, the second polarization grating 4, reflected by the third polarization grating 5 and propagates in the second waveguide body 2.
In this embodiment, the first polarization grating 3 and the second polarization grating 4 have different responses to the polarization states of the incident light, respectively, and thus crosstalk of the first light source and the second light source can be effectively reduced or avoided. On the other hand, the first light source and the second light source share one piece of the first waveguide body 1, so that the full-color waveguide display is more compact and lightweight in structure.
In one embodiment, referring to fig. 2, the first polarization grating 3 comprises a first out-coupling polarization grating 32. The second polarization grating 4 comprises a second out-coupling polarization grating 42. The third polarization grating 5 comprises a third out-coupling polarization grating 52;
the first and second out-coupling polarization gratings 32 and 42 are disposed on a side of the first waveguide body 1 remote from the second waveguide body 2, and the third out-coupling polarization grating 52 is disposed between the first waveguide body 1 and the second waveguide body 2.
In this embodiment, the first out-coupling polarization grating 32 and the second out-coupling polarization grating 42 are located in the out-coupling region of the first light-incident surface 11 of the first waveguide body 1, and the first out-coupling polarization grating 32 and the second out-coupling polarization grating 42 are juxtaposed in the thickness direction along the first waveguide body 1.
The first light source with the first polarization state diffracts into diffracted light through the first coupling-in polarization grating 31, enters the first waveguide body 1, propagates in total reflection until parallel light is output by diffraction of the first coupling-out polarization grating 32, and enters the human eye.
The second light source with the second polarization state diffracts into diffracted light through the second coupling-in polarization grating 41, enters the first waveguide body 1, propagates in total reflection until parallel light is output by diffraction of the second coupling-out polarization grating 42, and enters the human eye.
The third outcoupling polarization grating 52 serves as outcoupling means for the second waveguide body 2. The third out-coupling polarization grating 52 is located in the out-coupling region of the second light incident surface 21 of the second waveguide body 2.
The third light source with polarization state is diffracted by the third coupling-in polarization grating 51 to form diffracted light, which enters the second waveguide body 2 and propagates in total reflection until the third coupling-out polarization grating 52 diffracts the output parallel light into the human eye.
In one embodiment, the first polarization grating 3 and the second polarization grating 4 are each made of cholesteric liquid crystals having opposite optical rotation.
In this embodiment, the first polarization grating 3 and the second polarization grating 4 are prepared using cholesteric liquid crystals of opposite handedness, respectively, such that the first polarization grating 3 and the second polarization grating 4 are responsive to light of specifically different polarization states. The first polarization grating 3 and the second polarization grating 4 have different responses to the polarization state of the incident light, so that crosstalk between the first light source and the second light source can be effectively reduced or avoided.
For example, referring to fig. 1, the first polarization grating 3 and the second polarization grating 4 are both reflective polarization gratings. A schematic of the optical effects of two types of reflective polarizer gratings (r-PVG) is given in fig. 1. When right-hand circular polarization (RCP) and left-hand circular polarization (LCP) are used as incident light, the optical effect of the first reflective polarization grating (r-PVGI) is shown as (a) (b), and the optical effect of the second reflective polarization grating (r-PVGII) is shown as (c) (d).
As can be seen from fig. (a) (b), the first reflective polarization grating (r-PVGI) has a modulating effect on the right-hand circular polarization (RCP) incident light; the first reflective polarization grating (r-PVGI) has no modulating effect on the left-hand circular polarization state (LCP). As can be seen from the figures (c) and (d), the second reflective polarization grating (r-PVGII) has a modulating effect on the light incident in the left-hand circular polarization (LCP), and the second reflective polarization grating (r-PVGII) has no modulating effect on the light incident in the right-hand circular polarization (RCP). I.e. the reflective polarizer grating has a modulating effect on incident light of only one circular polarization state
Referring to fig. 2, the first polarization grating 3 employs a first reflective polarization grating (r-PVGI). Specifically, the first in-coupling polarization grating 31 employs a first type of reflective polarization grating (r-PVGI), and the first out-coupling polarization grating 32 employs a first type of reflective polarization grating (r-PVGI).
The second polarization grating 4 employs a second type of reflective polarization grating (r-PVGII). Specifically, the second in-coupling polarization grating 41 employs a second reflective polarization grating (r-PVGII), and the second out-coupling polarization grating 42 employs a second reflective polarization grating (r-PVGII).
In one embodiment, the third polarization grating 5 and the first polarization grating 3 are each made of cholesteric liquid crystals having the same optical rotation.
In this embodiment, the first polarization grating 3 and the second polarization grating 4 serve as coupling means for the first waveguide body 1, and the first polarization grating 3 and the second polarization grating 4 modulate incident light of different polarization states, respectively. The third polarization grating 5 serves as coupling means for the second waveguide body 2, the third polarization grating 5 modulating a third light source having a polarization state. Therefore, in this embodiment, the optical design of orthogonal polarization states is adopted in the input light (such as the third light source and the second light source, and the second light source and the first light source) with adjacent wavelengths, so that the crosstalk problem between the waveguide layers can be greatly reduced. In the prior art, the incident light is white light, and no polarization state design is performed, so that crosstalk problem may exist in the waveguide layer. In particular, there is a crosstalk problem between the red and green waveguide layers.
In this embodiment, the third polarization grating 5 and the first polarization grating 3 are each made of cholesteric liquid crystals having the same optical rotation. I.e. the third polarization grating 5 and the first polarization grating 3 have a modulating effect on the same type of polarized light. Referring to fig. 2, the third polarization grating 5 employs a first reflective polarization grating (r-PVGI). Specifically, the third in-coupling polarization grating 51 employs a first reflective polarization grating (r-PVGI), and the third out-coupling polarization grating 52 employs a first reflective polarization grating (r-PVGI). I.e. the third polarization grating 5 (r-PVGI) has a modulating effect on the right-hand circular polarization (RCP) incident light.
Thus in this embodiment the third light source is incident light of the same polarization as the first light source and the third light source is incident light of a different polarization than the second light source.
In this embodiment, the third light source is separately provided with one waveguide body, and the incident light of the third light source polarization state identical to the first light source polarization state is used, so that the crosstalk between the third light source and the second light source and the crosstalk between the third light source and the first light source can be avoided. In a specific embodiment, the third light source wavelength (620-630 nm) is different from the first light source wavelength (455-465 nm), and the first light source reflective polarization grating (r-PVG) is not responsive to the third light source, so that crosstalk of the third light source to the first light source can be avoided; the incident polarization states of the third light source and the second light source are different, so that mutual crosstalk between the third light source and the second light source can be avoided; the third light source reflective polarization grating (r-PVG) is responsive to the first light source with a small fringe field of view, and the first light source reflective polarization grating (r-PVG) itself has extremely high diffraction efficiency and can reach the third polarization grating 5 with negligible first light source, so that the first light source is also substantially free of crosstalk to the third light source.
In this embodiment, the full-color waveguide display structure has the characteristics of high efficiency, and can effectively correct color cast, and can realize high-efficiency color image transmission.
In one embodiment, the first polarization grating 3, the third polarization grating 5, and the second polarization grating 4 are all reflective polarization gratings.
Specifically, the first polarization grating 3, the third polarization grating 5 and the second polarization grating 4 all adopt reflection polarization gratings (r-PVGs), so that the field angle of the full-color waveguide display structure can be improved, and further, color image transmission with a large viewing angle is realized.
The first light source, the second light source and the third light source can be any one of red light, blue light and green light respectively. For example, in one embodiment, the first light source is red light, the second light source is blue light, and the third light source is green light; or in yet another embodiment, the first light source is red light, the second light source is green light, and the third light source is blue light; or the first light source is green light, the second light source is red light, and the third light source is blue light; or the first light source is green light, the second light source is blue light, and the third light source is red light; or the first light source is blue light, the second light source is red light, and the third light source is green light; or the first light source is blue light, the second light source is green light, and the third light source is red light.
Since the first polarization grating and the third polarization grating respond to polarized light of the same polarization state, the first polarization grating needs to respond differently to the first light source and the third light source having the same polarization state. Therefore, the first polarization grating and the third polarization grating need to reflect light with the same polarization state but different wavebands respectively to implement the scheme.
Therefore, in order to ensure that the third light source does not interfere when passing through the first polarization grating, it is preferable that the wavelengths of the first light source and the third light source differ greatly. Therefore, the first light source and the third light source are preferably red light or blue light, respectively. For example, in a preferred embodiment, the first light source is blue light, the second light source is green light, and the third light source is red light; or in a preferred embodiment the first light source is red light, the second light source is green light and the third light source is blue light.
In one embodiment, the period of the first polarization grating 3 is 360-370nm, and the Bragg period is 160-165nm; the period of the second polarization grating 4 is 410-420nm, and the Bragg period is 185-190nm; the period of the third polarization grating 5 is 490-500nm, and the Bragg period is 220-225nm.
In this embodiment, taking the example of a polarization angle of 53 °: the wavelength range of the first light source is 455-465nm, the corresponding period of the first polarization grating 3 (for example, B-PVG) is 360-370nm, and the Bragg period is 160-165nm, so that the first light source polarization grating has high diffraction efficiency on the first light source. The wavelength of the second light source ranges from 520 nm to 530nm, and the second polarization grating 4 (for example, may be G-PVG) corresponds to a period of 410 nm to 420nm and a bragg period of 185 nm to 190nm, so that the second light source polarization grating has high diffraction efficiency for the second light source. The wavelength range of the third light source is 620-630nm, and the third light source polarization grating (for example, R-PVG) corresponds to 490-500nm period and 220-225nm Bragg period, so that the red polarization grating has high diffraction efficiency on the third light source.
In one embodiment, the first waveguide body 1 and the second waveguide body 2 are both transparent slab structures.
In this embodiment, the first waveguide body 1 and the second waveguide body 2 are both transparent slab structures. For example, the first waveguide body 1 and the second waveguide body 2 are both transparent glass plates or transparent plastic plates. In this embodiment, high-transparency color image transmission can be realized.
In one embodiment, the full color waveguide display structure has a field angle in the range of 30 ° -45 °.
In this embodiment, the first light source with the first polarization state corresponds to the first light source polarization state grating, the second light source with the second polarization state corresponds to the second light source polarization state grating, and the designs of the independent first light source polarization state grating and the independent second light source polarization state grating can improve the field angle of the full-color waveguide display structure. In the prior art, blue-green light is multiplexed with a piece of blue-green polarization grating, but the field angle of blue-green light is reduced. In the embodiment, the full-color waveguide display structure has an angle of view ranging from 30 degrees to 45 degrees, and can realize color image transmission with a large angle of view.
According to a second aspect of embodiments of the present application, a head mounted display device is provided. The head mounted display device comprises the full color waveguide display structure of the first aspect. In particular, the full-color waveguide display structure is applied to the head-mounted display device, so that on one hand, the imaging effect of the head-mounted display device is improved, and on the other hand, the structure of the head-mounted display device is more compact and lighter. The head mounted display device is for example an augmented reality display device, which may be for example AR glasses or an AR head mounted device.
The foregoing embodiments mainly describe differences between the embodiments, and as long as there is no contradiction between different optimization features of the embodiments, the embodiments may be combined to form a better embodiment, and in consideration of brevity of line text, no further description is given here.
Although specific embodiments of the present application have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present application. The scope of the application is defined by the appended claims.
Claims (11)
1. A full-color waveguide display structure, comprising: the first and third gratings are of the same type and the corresponding first and third light sources are of the same polarization state, in which case,
a first waveguide body (1), the first waveguide body (1) being for propagating a first light source and a second light source;
a first polarization grating (3) and a second polarization grating (4), wherein the first polarization grating (3) and the second polarization grating (4) are used as coupling devices of the first waveguide body (1) and respectively respond to polarized light with different polarization states;
a second waveguide body (2), the second waveguide body (2) being located at one side of the first waveguide body (1), the second waveguide body (2) being used for propagating a third light source;
-a third polarization grating (5), said third polarization grating (5) acting as coupling means for said second waveguide body (2).
2. The full-color waveguide display structure of claim 1, wherein,
the first polarization grating (3) comprises a first incoupling polarization grating (31);
the second polarization grating (4) comprises a second incoupling polarization grating (41);
the third polarization grating (5) comprises a third incoupling polarization grating (51);
the first coupling-in polarization grating (31) and the second coupling-in polarization grating (41) are arranged between the first waveguide body (1) and the second waveguide body (2), and the third coupling-in polarization grating (51) is arranged on one side, far away from the first waveguide body (1), of the second waveguide body (2).
3. The full-color waveguide display structure according to claim 1 or 2, wherein,
the first polarization grating (3) comprises a first out-coupling polarization grating (32);
the second polarization grating (4) comprises a second out-coupling polarization grating (42);
the third polarization grating (5) comprises a third out-coupling polarization grating (52);
the first and second out-coupling polarization gratings (32, 42) are arranged on one side of the first waveguide body (1) away from the second waveguide body (2), and the third out-coupling polarization grating (52) is arranged between the first waveguide body (1) and the second waveguide body (2).
4. A full colour waveguide display structure according to claim 1, characterized in that the first polarization grating (3) and the second polarization grating (4) are each made of cholesteric liquid crystals of opposite optical rotation.
5. A full colour waveguide display structure according to claim 1 or 4, characterized in that the third polarization grating (5) and the first light polarization grating (3) are each made of cholesteric liquid crystals of the same optical rotation.
6. The full-color waveguide display structure according to claim 1, characterized in that the first polarization grating (3), the third polarization grating (5) and the second polarization grating (4) are all reflective polarization gratings.
7. The full-color waveguide display structure according to claim 1, wherein the first light source and the third light source are light of a first circular polarization state having different wavelengths, and the second light source is light of a second circular polarization state;
the first light source is reflected by the first polarization grating after incidence and propagates in the first waveguide body;
the second light source is reflected by the second polarization grating after being incident and propagates in the first waveguide body;
the third light source is transmitted by the first polarization grating and the second polarization grating after being incident, reflected by the third polarization grating and propagates in the second waveguide body.
8. The full-color waveguide display structure of claim 1, wherein,
the period of the first polarization grating (3) is 360-370nm, and the Bragg period is 160-165nm;
the period of the second polarization grating (4) is 410-420nm, and the Bragg period is 185-190nm;
the period of the third polarization grating (5) is 490-500nm, and the Bragg period is 220-225nm.
9. The full-color waveguide display structure according to claim 1, characterized in that the first waveguide body (1) and the second waveguide body (2) are both transparent slab structures.
10. The full-color waveguide display structure of claim 1, wherein the full-color waveguide display structure has a field angle in the range of 30 ° -45 °.
11. A head-mounted display device comprising a full color waveguide display structure as claimed in any one of claims 1-10.
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| CN202111613341.2A CN116400499A (en) | 2021-12-27 | 2021-12-27 | Full-color waveguide display structure and head-mounted display device |
| PCT/CN2022/100378 WO2023123922A1 (en) | 2021-12-27 | 2022-06-22 | Full-color waveguide display structure and head-mounted display device |
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| JP6895451B2 (en) * | 2016-03-24 | 2021-06-30 | ディジレンズ インコーポレイテッド | Methods and Devices for Providing Polarized Selective Holography Waveguide Devices |
| EP3602156A4 (en) * | 2017-03-21 | 2020-12-23 | Magic Leap, Inc. | Display system with spatial light modulator illumination for divided pupils |
| CN208314330U (en) * | 2018-02-13 | 2019-01-01 | 成都理想境界科技有限公司 | A kind of nearly eye display optical system of simple eye big visual field and head-mounted display apparatus |
| US11092808B1 (en) * | 2018-03-20 | 2021-08-17 | Facebook Technologies, Llc | Waveguide with multilayer waveplate |
| CN110824613A (en) * | 2019-11-13 | 2020-02-21 | 东南大学 | Polarization multiplexing waveguide display device |
| CN110727116A (en) * | 2019-11-13 | 2020-01-24 | 东南大学 | Two-dimensional pupil expanding method based on polarizer holographic grating |
| CN212846017U (en) * | 2020-09-25 | 2021-03-30 | 歌尔股份有限公司 | Optical waveguide lens, augmented reality display module and augmented reality display glasses |
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