Optical module and head-mounted display device

Abstract

The embodiment of the present application provides an optical module and a head-mounted display device; wherein the optical module comprises an optical machine and a light guide device; the optical machine is used for emitting light rays of multiple different wave bands; the light guide device comprises a transparent substrate and a coupling-in area and a coupling-out area arranged on the transparent substrate; the coupling-in area comprises multiple coupling-in gratings with different grating structures, each of which can be used for coupling in light rays of a corresponding wave band, the coupling-in area is used for coupling at least one wave band of light rays into the transparent substrate and enabling the coupled light rays to totally reflect and propagate in the transparent substrate to the coupling-out area; the coupling-out area is used for coupling out the light rays propagating to the coupling-out area, and the coupling-out area comprises multiple coupling-out gratings, wherein the coupling-out gratings with different grating structures are used for coupling out light rays of different wave bands, and the coupling-out gratings with the same grating structure are used for coupling out light rays of the same wave band. The light waveguide scheme provided by the embodiment of the present application can play a role in transmitting color pictures in augmented reality products.

Description

Technical Field

[0001] This application relates to the field of optical imaging technology, and more specifically, to an optical module and a head-mounted display device. Background Technology

[0002] Transmitting color images in augmented reality (AR) products has always been a challenge for AR manufacturers. Monochromatic light waveguide AR products are limited by their single display effect and applicable scenarios, and are mainly used for light interactive functions such as information reminders, navigation, and translation.

[0003] Currently, most mature full-color AR products on the market use Birdbath and freeform surface solutions. However, full-color waveguide AR products are less mature compared to these two solutions, and their color imaging and color reproduction are not satisfactory, resulting in a poor user visual experience. There is an urgent need to fill this gap in the AR product market. Summary of the Invention

[0004] The purpose of this application is to provide a new technical solution for an optical module and a head-mounted display device, which solves the problem of poor color display effect in existing optical waveguide AR products.

[0005] In a first aspect, this application provides an optical module. The optical module includes:

[0006] Optical engines are used to emit light in various wavelengths.

[0007] A light guiding device includes a transparent substrate and a coupling-in region and a coupling-out region disposed on the transparent substrate;

[0008] The coupling region includes multiple coupling gratings with different grating structures. Each coupling grating can be used to couple light of a wavelength corresponding to that coupling grating. The coupling region is used to couple light of at least one wavelength into the transparent substrate and enables the coupled light to be totally internally reflected within the transparent substrate and propagated to the coupling region.

[0009] The coupling region is used to couple out light propagating to the coupling region. The coupling region includes multiple coupling gratings, wherein coupling gratings with different grating structures are used to couple out light of different wavelengths, and coupling gratings with the same grating structure are used to couple out light of the same wavelength.

[0010] Optionally, the optical engine is configured such that the light emitted by it in multiple different wavelengths can be combined to form multiple imaging light rays with different color mixing ratios, and each color mixing ratio of the imaging light rays corresponds to forming a virtual image of a color combination.

[0011] The optical engine projects imaging light of the target color mixing ratio into the coupling region; at the location of the coupling region, each of the coupling gratings is used to couple in light of the target color mixing ratio containing light of the corresponding wavelength band of the coupling grating, and to make the coupled light propagate to the coupling region by total internal reflection; at the location of the coupling region, the plurality of coupling gratings respectively couple out the light, and all the coupled light rays are converged to form a virtual image with the target color combination.

[0012] Optionally, the imaging light of any of the color mixing ratios includes at least two different wavelengths, wherein the intensity of the light of each wavelength can be adjusted when it is projected onto the coupling region.

[0013] Optionally, the plurality of different coupling gratings are located on the same plane and are arranged in a partitioned manner within the coupling region;

[0014] The coupling gratings are configured in a one-to-one correspondence with the wavelengths of the light emitted by the optomechanical system, so that each coupling grating can couple in a wavelength of light.

[0015] Each of the coupling gratings in the coupling region has at least one coupling grating in the coupling region corresponding to the coupling grating, and light rays coupled in from a coupling grating can be coupled out through at least one coupling grating corresponding to the coupling grating.

[0016] Optionally, the plurality of coupling gratings are located on the same plane and arranged in a matrix within the coupling region;

[0017] The plurality of coupling gratings includes at least two different grating structures, and each grating structure has one or more coupling gratings.

[0018] Optionally, by adjusting at least one of the grating parameters among the grating period, duty cycle, groove depth, and sidewall tilt angle of the coupled-in grating and the coupled-out grating, it is possible to form at least two coupled-in gratings with different grating structures in the coupled-in region, at least two coupled-out gratings with different grating structures in the coupled-out region, and to ensure that each coupled-in grating has at least one coupled-out grating corresponding to it in the coupled-out region.

[0019] Optionally, the light guiding device is a diffractive waveguide device.

[0020] Optionally, the light emitted by the optical engine includes red light, green light, and blue light;

[0021] The coupling region includes a first coupling grating, a second coupling grating, and a third coupling grating;

[0022] The coupling region includes a first coupling grating, a second coupling grating, and a third coupling grating, and the first coupling grating, the second coupling grating, and the third coupling grating are each configured as multiple;

[0023] The first coupling grating is used to couple in red light, and the first coupling grating corresponds to the first coupling out grating;

[0024] The second coupling grating is used to couple in green light, and the second coupling grating corresponds to the second coupling out grating;

[0025] The third coupling grating is used to couple in green light, and the third coupling grating corresponds to the third coupling out grating.

[0026] Optionally, the red light emitted by the optomechanical system is coupled into the transparent substrate through the first coupling grating and propagated to the coupling region by total internal reflection. The light can be coupled out through all of the first coupling gratings at the location of the coupling region.

[0027] The green light emitted by the optomechanical system is coupled into the transparent substrate through the second coupling grating and propagates to the coupling region by total internal reflection. The light can be coupled out through all the second coupling gratings at the position of the coupling region.

[0028] The blue light emitted by the optomechanical system is coupled into the transparent substrate through the third coupling grating and propagates to the coupling region by total internal reflection. The light can be coupled out through all of the third coupling gratings at the location of the coupling region.

[0029] Secondly, this application provides a head-mounted display device. The head-mounted display device includes:

[0030] Casing; and

[0031] The optical module as described in the first aspect.

[0032] Optionally, the head-mounted display device is smart glasses or a smart helmet, which includes:

[0033] A front frame assembly, wherein a left lens mounting portion and a right lens mounting portion are provided on the front frame assembly, and a bridge portion is provided between the left lens mounting portion and the right lens mounting portion;

[0034] The optical module is configured as two:

[0035] One of the optical modules has a transparent substrate disposed within the left lens mounting portion, and the optical engine of the optical module is disposed at the end of the left lens mounting portion away from the bridge of the nose and opposite to the coupling area on the transparent substrate, and the coupling area on the transparent substrate is opposite to the user's left eye.

[0036] Another optical module has a transparent substrate disposed within the right lens mounting portion, and the optical engine of the optical module is disposed at the end of the right lens mounting portion away from the bridge of the nose and opposite to the coupling area on the transparent substrate, and the coupling area on the transparent substrate is opposite to the user's right eye.

[0037] The beneficial effects of this application are as follows:

[0038] The optical module provided in the embodiments of this application mainly consists of an optical engine that can emit colored light and a light guide device for transmitting light. The coupling area on the light guide device can couple in the colored light emitted by the optical engine, and a colored image can be formed in the coupling area. This optical module is applicable to augmented reality products and can play an important role in transmitting colored image light in augmented reality products. The optical solution provided in this application greatly improves the color imaging effect of optical display images.

[0039] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0041] Figure 1 This is a schematic diagram of the structure of the optical module provided in the embodiments of this application;

[0042] Figure 2 This is a schematic diagram of the coupling region on the light guide device provided in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the coupling region on the light guide device provided in an embodiment of this application.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Optical engine; 2. Transparent substrate; 3. Coupled-in region; 31. First coupling-in grating; 32. Second coupling-in grating; 33. Third coupling-in grating; 4. Coupled-out region; 41. First coupled-out grating; 42. Second coupled-out grating; 43. Third coupled-out grating. Detailed Implementation

[0046] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0047] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0048] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0049] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0051] The following is in conjunction with the appendix Figures 1 to 3 The optical module and head-mounted display device provided in the embodiments of this application will be described in detail.

[0052] According to one aspect of the embodiments of this application, an optical module is provided, which is suitable for application in wearable devices. The wearable device is, for example, a head-mounted display (HMD), such as an AR head-mounted display. Furthermore, the specific form of the head-mounted display device may be, for example, smart glasses or a smart helmet, etc., and the embodiments of this application do not limit the specific form of the head-mounted display device.

[0053] According to one embodiment of this application, an optical module is provided, see [link to relevant documentation]. Figure 1 The optical module includes an optomechanical system 1 and a light guide device. The optomechanical system 1 emits light of various wavelengths. The light guide device includes a transparent substrate 2 and a coupling-in region 3 and a coupling-out region 4 disposed on the transparent substrate 2. See also... Figure 2 The coupling region 3 includes multiple coupling gratings with different grating structures. Each coupling grating is used to couple light of a corresponding wavelength band. The coupling region 3 is used to couple light of at least one wavelength band into the transparent substrate 2, and enables the coupled light to undergo total internal reflection within the transparent substrate 2 to propagate to the coupling region 4. See also Figure 3 The coupling region 4 is used to couple out the light propagating to the coupling region 4. The coupling region 4 includes a plurality of coupling gratings, wherein the coupling gratings with different grating structures are used to couple out light of different wavelengths, and the coupling gratings with the same grating structure are used to couple out light of the same wavelength.

[0054] According to the above embodiments of this application, the optical module mainly consists of an optomechanical unit 1 and a light guide device, and the optical architecture of the entire optical module is simple. The light guide device is, for example, a thin sheet structure, which is relatively thin and light, which helps to reduce the size and weight of the entire optical module.

[0055] For example, the optical module in the above embodiments can be applied to, for example, AR products. The light guide device in the optical module, through a special arrangement of the grating structures in the coupling-in region 3 and the coupling-out region 4, achieves efficient transmission of colored light, enabling the virtual image formed by the optical module to have more realistic colors, thereby enhancing the user's visual experience.

[0056] According to the above embodiments of this application, the optical module includes a light guide device. The structure of the light guide device includes a transparent substrate 2, on which a coupling-in region 3 and a coupling-out region 4 are disposed; wherein, both the coupling-in region 3 and the coupling-out region 4 are divided into multiple independent sub-regions, see [reference]. Figure 2 and Figure 3 .

[0057] Taking the design of the coupling region 3 as an example, a diffraction grating with a specific grating structure is set in each sub-region. This creates multiple coupling gratings with different grating structures within the coupling region 3, and each coupling grating is independently set. Based on this, multiple coupling gratings are also formed in partitioned areas within the coupling region 4. It should be noted that among the multiple coupling gratings set in the coupling region 4, there are both coupling gratings with different grating structures and coupling gratings with the same grating structure. In other words, coupling gratings with different grating structures are set in the coupling region 4, and the number of coupling gratings of each grating structure is not limited to one; multiple gratings can be set.

[0058] The optical module provided in the embodiments of this application employs a specially designed light guide device to transmit colored light. The colored light includes, for example, red, green, and blue light. It should be noted that this application does not limit the wavelength (color) or brightness of the colored light, nor does it limit the number of wavelengths (colors) included in the colored light. For example, the colored light may include two different wavelengths, and of course, it may include three or more different wavelengths.

[0059] In the embodiments of this application, the optomechanical system 1 can emit colored light. The coupling region 3 is pre-divided into multiple coupling gratings with different grating structures, and the grating structure of the coupling grating corresponds to the wavelength of the light. This allows the coupling region 3 to couple light of different wavelengths through coupling gratings with different grating structures, and the coupled light is propagated by total internal reflection within the transparent substrate 2 to the coupling region 4. Then, different coupling gratings in the coupling region 4 couple the light of different wavelengths out. After the light of different wavelengths converges, a colored imaging image can be formed.

[0060] In one example, see Figure 2 The coupling region 3 includes three coupling gratings with different structures, defined as a first coupling grating 31, a second coupling grating 32, and a third coupling grating 33. The colored light emitted by the optomechanical system 1 includes three different wavelengths: a first wavelength, a second wavelength, and a third wavelength. In this example, the first coupling grating 31 is designed to couple the first wavelength, the second coupling grating 32 is designed to couple the second wavelength, and the third coupling grating 33 is designed to couple the third wavelength. That is, the coupling region 3 can couple different wavelengths of light through the first coupling grating 31, the second coupling grating 32, and the third coupling grating 33. The coupled wavelengths of light can propagate within the transparent substrate 2 in a state of total internal reflection.

[0061] Based on the above example, see Figure 3 The coupling region 4 includes three different grating structures for the coupling gratings, defined as a first coupling grating 41, a second coupling grating 42, and a third coupling grating 43, respectively. Multiple copies of each of these grating structures are configured. Specifically, the first coupling grating 41 is used to couple out the first light ray coupled into the first coupling grating 31; the second coupling grating 42 is used to couple out the second light ray coupled into the second coupling grating 32; and the third coupling grating 43 is used to couple out the third light ray coupled into the third coupling grating 33. In other words, within the coupling region 4, the coupling gratings with different structures can couple out light rays of different wavelengths. Finally, the first, second, and third light rays coupled out of the light guide device converge to form a colored image.

[0062] It should be noted that the coupling region 3 includes, but is not limited to, setting three different coupling gratings; two or more different coupling gratings can also be set, as long as they can adapt to the optical transmission requirements of different wavelength bands. Furthermore, the coupling region 4 is not limited to setting three different coupling gratings, and there is no limit to the number of each type of coupling grating; it can be designed according to specific needs.

[0063] One form of the grating arrangement rule in the coupling region 4 is as follows: Figure 3 As shown, coupling gratings corresponding to different wavelengths (colors) of light are arranged in a certain pattern within the coupling region 4 on the transparent substrate 2. Each coupling grating is independent of the others and does not interfere with them. The area of ​​each coupling grating can be freely divided; any side length in the range of hundreds of nanometers to hundreds of micrometers can be defined and divided through grating design. The smaller the side length of each coupling grating, i.e., the area it occupies, the more uniform its arrangement on the transparent substrate 2, resulting in a better display effect.

[0064] According to the optical module provided in the above embodiments of this application, light rays of different wavelengths coupled into the coupling region 3 can be designed to be emitted from the same optomechanical unit 1. See [link to relevant documentation]. Figure 1 In this way, there is no need to increase the number of optical engines, and there is no increase in cost, size, or weight of the entire optical module.

[0065] The optical engine 1, for example, is a display optical engine, which can be used to emit light carrying image information. The light guide device, as a light transmission device, can be used to transmit the light emitted by the optical engine 1 and can couple the light out to form an image in, for example, the human eye. The image is also the virtual image formed after the imaging light passes through the optical module.

[0066] Figure 1 A schematic diagram of the light guide device is shown. Figure 2 The coupling region 3 shown is disposed on the transparent substrate 2 of the light guide device, and the coupling region 4 is also disposed on the transparent substrate 2.

[0067] For example, the coupling-in region 3 and the coupling-out region 4 can be disposed on the same surface of the transparent substrate 2. Of course, the coupling-in region 3 and the coupling-out region 4 can also be disposed on two opposite surfaces of the transparent substrate 2. This application does not impose specific restrictions on the placement of the coupling-in region 3 and the coupling-out region 4 on the transparent substrate 2.

[0068] The optical module provided in this application embodiment can be applied to, for example, AR products, and has a high-efficiency transmission function for colored light, which can make the colors presented by the optical display effect more realistic.

[0069] The optical module provided in the embodiments of this application mainly consists of an optical engine that can emit colored light and a light guide device for transmitting light. The coupling area on the light guide device can couple in the colored light emitted by the optical engine, and a colored image can be formed in the coupling area. This optical module is applicable to augmented reality products and can play an important role in transmitting colored image light in augmented reality products. The optical solution provided in this application greatly improves the color imaging effect of optical display images.

[0070] In some examples of this application, the optomechanism 1 is configured such that the light emitted by it in multiple different wavelengths can be combined to form multiple imaging light rays with different color mixing ratios, and each color mixing ratio imaging light ray corresponds to forming a virtual image of a color combination. The optomechanism 1 projects the imaging light ray with the target color mixing ratio into the coupling region 3; at the location of the coupling region 3, each coupling grating is used to couple in the light rays in the target color mixing ratio imaging light rays that correspond to the wavelength of the coupling grating, and propagates the coupled light rays through total internal reflection to the coupling region 4; at the location of the coupling region 4, the plurality of coupling gratings respectively couple out the light rays, and all the coupled light rays are converged to form a virtual image with the target color combination.

[0071] According to the above example, optionally, the imaging light of each of the color mixing ratios includes at least two different wavelengths; wherein the intensity of the light of each wavelength can be adjusted when it is projected onto the coupling region 3.

[0072] In other words, the optical module also has the function of adjusting the color of the formed image (i.e., virtual image).

[0073] Specifically, when it is necessary to adjust the color of the image formed by the optical module, for example, the optical engine 1 can be controlled to switch to emitting imaging light with a corresponding color mixing ratio and projecting it onto the coupling area 3, that is, the imaging light with the target color mixing ratio. Furthermore, the color and brightness of the light emitted from the corresponding position in the coupling area 4 can be changed by adjusting the intensity of each light beam projected by the optical engine 1 onto three different coupling gratings. The light beams coupled out of the coupling area 4 converge to form a complete color image.

[0074] Based on the above example, the optical module can further enhance the applicable scenarios of augmented reality products, solve the problems of color light image transmission distortion and difficulty in color adjustment that currently exist in augmented reality products, and bring users a more realistic visual experience.

[0075] In some examples of this application, the plurality of different coupling gratings are located on the same plane and are arranged in a partitioned manner within the coupling region 3; the coupling gratings are arranged in a one-to-one correspondence with the wavelength bands of the light emitted by the optomechanical 1, so that each coupling grating can couple in a wavelength band of light; each coupling grating in the coupling region 3 has at least one coupling grating corresponding to the coupling grating in the coupling region 4, so that the light coupled in by the coupling grating can be coupled out by at least one coupling grating corresponding to the coupling grating.

[0076] In some examples of this application, the plurality of coupling gratings are located on the same plane and arranged in a matrix within the coupling region 4; wherein, the plurality of coupling gratings include coupling gratings with at least two different grating structures, and each type of grating structure is provided as one or more coupling gratings.

[0077] See Figure 2 The coupling region 3 includes, for example, three different coupling gratings, namely... Figure 2 The first coupling grating 31, the second coupling grating 32 and the third coupling grating 33 shown in the figure have different grating parameters to form different grating structures, which can couple in three different wavelengths (colors) of light.

[0078] It should be noted that the coupling region 3 includes, but is not limited to, setting three coupling gratings with different grating structures, and the number of coupling gratings can be designed according to actual needs.

[0079] For example, the number of coupling gratings in the coupling region 3 can be set to 2 to 20.

[0080] Preferably, the number of coupling gratings in the coupling region 3 is set to less than 15.

[0081] If too many coupling gratings are set in a coupling region, such as more than 20, the size of each coupling grating will be too small due to the limited size of the coupling region itself, which will affect the imaging.

[0082] According to some examples of this application, by adjusting at least one of the grating parameters of the coupled-in grating and the coupled-out grating, such that at least two coupled-in gratings with different grating structures are formed in the coupled-in region 3, at least two coupled-out gratings with different grating structures are formed in the coupled-out region 4, and each coupled-in grating has at least one coupled-out grating corresponding to it in the coupled-out region 4.

[0083] According to the above example, if the light rays of different wavelengths emitted from the optomechanical 1 can be incident through the input grating and exited through the output grating, then the correspondence between the input grating and the output grating needs to be satisfied.

[0084] Specifically, the correspondence between the grating parameters such as grating period, duty cycle, slot depth, and sidewall tilt angle of the input and output gratings can be found in [reference needed]. Figure 2 and Figure 3The grating parameters of the first coupling grating 31 are designed as D1, and the grating parameters of the first coupling grating 41 are designed as A1. When D1 = A1, it indicates that the first coupling grating 31 and the first coupling grating 41 have a corresponding relationship. Thus, light rays (such as red light) coupled into the transparent substrate 2 through the first coupling grating 31 can be totally internally reflected to the coupling region 4 and coupled out through the first coupling grating 41. Similarly, the grating parameters of the second coupling grating 32 are designed as D2, and the grating parameters of the second coupling grating 42 are designed as A2. When D2 = A2, it indicates that the second coupling grating 32 and the second coupling grating 42 have a corresponding relationship. The grating parameters of the third coupling grating 33 are designed as D3, and the grating parameters of the third coupling grating 43 are designed as A3. When D3 = A3, it indicates that the third coupling grating 33 and the third coupling grating 43 have a corresponding relationship. It is important to emphasize that the equal sign here means that there is a unique correspondence between the grating parameters such as the grating period, duty cycle, slot depth, and sidewall tilt angle of the coupled-in grating and the corresponding coupled-out grating. The grating can only work normally if this correspondence is met. It does not mean that the grating parameters such as the grating period, duty cycle, slot depth, and sidewall tilt angle of the coupled-in grating and the coupled-out grating are equal everywhere.

[0085] According to the above example, within the coupling region 4 on the transparent substrate 2, the coupling grating with the same grating structure or grating parameters is not limited to only one. See also Figure 3 The first coupling grating 41, the second coupling grating 42, and the third coupling grating 43 can each be configured as multiple. In this case, light of the same wavelength (color) can be coupled out through multiple identical coupling gratings, which can improve the display effect.

[0086] According to the above example, the coupling region 3 is composed of three different coupling gratings, namely a first coupling grating 31, a second coupling grating 32, and a third coupling grating 33. See [reference needed] Figure 2 The three coupling gratings have different grating parameters, which can be defined as D1, D2, and D3, respectively. Each coupling grating corresponds to a specific wavelength of light. For example, if the light emitted by the optomechanic includes red, green, and blue light, then D1, D2, and D3 represent the grating parameters of the three coupling gratings corresponding to the red, green, and blue light within the coupling region 3, respectively.

[0087] The light coupled into the coupling region 3 undergoes total internal reflection in the transparent substrate 2, and the position of the coupling region 4 is changed by the corresponding coupling grating to change the deflection angle of the light before it enters the human eye.

[0088] Based on the example above, see Figure 3The coupling region 4 includes multiple coupling gratings, and these coupling gratings include three different types of coupling gratings, namely... Figure 3 The first coupling grating 41, the second coupling grating 42, and the third coupling grating 44 shown are illustrated. The grating parameters corresponding to these three coupling gratings can be represented by A1, A2, and A3, respectively. It should be noted that, due to the characteristics of diffraction gratings, each coupling grating only deflects light rays incident at a specific angle, while not altering the propagation path of other light rays that cannot be affected by the grating. Thus, when totally internally reflected light rays illuminate the coupling region 4 within the light guide device, the light rays may be coupled out only after being acted upon by the corresponding coupling grating.

[0089] The light emitted by the optical engine 1 can cover the coupling region 3. This design allows the light emitted by the optical engine to be projected onto the coupling region 3 without moving the optical engine.

[0090] In some examples of this application, the light guiding device is a diffractive waveguide device.

[0091] Optionally, the transparent substrate 2 of the light guide device may be made of glass, resin, or ceramic.

[0092] Optionally, the coupling-in grating and the coupling-out grating are thin-film diffraction gratings.

[0093] The coupled-in grating and the coupled-out grating can be designed as extremely thin grating film layers, which makes the formed light guide device thin and light, which is conducive to realizing the thin and light design of optical modules.

[0094] Optionally, the thickness of a single coupled grating can range from 3 micrometers to hundreds of micrometers.

[0095] For example, the thickness of a single coupled grating ranges from 3 micrometers to 150 micrometers.

[0096] Optionally, the coupled-in grating and the coupled-out grating can be thin-film diffraction gratings such as surface relief gratings or volume holographic gratings.

[0097] The optical module provided in this application is a diffractive waveguide augmented reality optical solution, which can be applied to, for example, head-mounted display devices, especially head-mounted display products. The optical module provided in this application can further expand the applicable scenarios of waveguide-based augmented reality products, solve the problems of color image transmission distortion and difficulty in color adjustment in waveguide-based augmented reality products, and provide users with a more realistic augmented reality experience.

[0098] See some examples in this application. Figures 1 to 3The light emitted by the optical engine 1 includes red light, green light, and blue light; the coupling region 3 includes a first coupling grating 31, a second coupling grating 32, and a third coupling grating 33; the coupling region 4 includes a first coupling grating 41, a second coupling grating 42, and a third coupling grating 43, and the first coupling grating 41, the second coupling grating 42, and the third coupling grating 43 are respectively configured as multiple; the first coupling grating 31 is used to couple red light, and the first coupling grating 31 corresponds to the first coupling grating 41; the second coupling grating 32 is used to couple green light, and the second coupling grating 32 corresponds to the second coupling grating 42; the third coupling grating 33 is used to couple green light, and the third coupling grating 33 corresponds to the third coupling grating 43.

[0099] According to the above example, the red light emitted by the optomechanical 1 is coupled into the transparent substrate 2 via the first coupling grating 31 and propagates to the coupling region 4 via total internal reflection. At the position of the coupling region 4, it can be coupled out via all the first coupling gratings 41. The green light emitted by the optomechanical 1 is coupled into the transparent substrate 2 via the second coupling grating 32 and propagates to the coupling region 4 via total internal reflection. At the position of the coupling region 4, it can be coupled out via all the second coupling gratings 42. The blue light emitted by the optomechanical 1 is coupled into the transparent substrate 2 via the third coupling grating 33 and propagates to the coupling region 4 via total internal reflection. At the position of the coupling region 4, it can be coupled out via all the third coupling gratings 43.

[0100] According to another aspect of the embodiments of this application, a head-mounted display device is also provided, the head-mounted display device including a housing and an optical module as described above.

[0101] The head-mounted display device is, for example, an AR head-mounted device, including AR glasses or an AR helmet, etc., and this application embodiment does not impose specific limitations on it.

[0102] In some examples of this application, the head-mounted display device is a smart glasses or a smart helmet, which includes: a front frame assembly, on which a left lens mounting portion and a right lens mounting portion are provided, and a bridge portion is provided between the left lens mounting portion and the right lens mounting portion.

[0103] The optical modules are configured in two parts. One optical module has a transparent substrate 2 located within the left lens mounting portion, and its optical engine 1 is located at the end of the left lens mounting portion away from the bridge of the nose, opposite to the coupling area 3 on the transparent substrate 2. The coupling area 4 on the transparent substrate 2 is opposite to the user's left eye. The other optical module has a transparent substrate 2 located within the right lens mounting portion, and its optical engine 1 is located at the end of the right lens mounting portion away from the bridge of the nose, opposite to the coupling area 3 on the transparent substrate 2. The coupling area 4 on the transparent substrate 2 is opposite to the user's right eye.

[0104] According to the above example, the head-mounted display device may further include: a head-mounted wearing component and a frame-type wearing component, wherein the head-mounted wearing component and the frame-type wearing component are detachably connected to the front frame component so that the head-mounted wearing component and the frame-type wearing component can be interchangeably fitted to the front frame component.

[0105] The specific implementation of the head-mounted display device in this application can refer to the above-described embodiments of the optical module. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0106] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0107] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An optical module, characterized in that, include: Optical mechanism (1), used to emit light in various different wavelengths; The light guide device includes a transparent substrate (2) and a coupling region (3) and a coupling region (4) disposed on the transparent substrate (2). The coupling region (3) includes multiple coupling gratings with different grating structures. Each coupling grating can be used to couple light of the corresponding wavelength band. The coupling region (3) is used to couple light of at least one wavelength band into the transparent substrate (2) and enables the coupled light to be totally internally reflected in the transparent substrate (2) and propagated to the coupling region (4). The coupling region (4) is used to couple out the light propagating to the coupling region (4). The coupling region (4) includes a plurality of coupling gratings, wherein the coupling gratings with different grating structures are used to couple out light of different wavelengths, and the coupling gratings with the same grating structure are used to couple out light of the same wavelength. The optical engine (1) is configured such that the light emitted by it in various different wavelengths can be combined to form imaging light with various different color mixing ratios, and each color mixing ratio of the imaging light corresponds to forming a virtual image of a color combination. The optical engine (1) projects the imaging light of the target color mixing ratio into the coupling area (3); at the position of the coupling area (3), each of the coupling gratings is used to couple in the light of the target color mixing ratio containing the light of the corresponding wavelength band of the coupling grating, and to make the coupled light propagate to the coupling area (4) by total internal reflection; at the position of the coupling area (4), the plurality of coupling gratings couple out the light respectively, and all the coupled light rays are converged to form a virtual image with the target color combination; The plurality of different coupling gratings are located on the same plane of the transparent substrate (2) in the coupling region (3) and are arranged in a partitioned manner. The plurality of coupling gratings are located on the same plane in the coupling region (4) and are arranged in a matrix. The plurality of coupling gratings include at least two different grating structures, and each grating structure has a plurality of coupling gratings.

2. The optical module according to claim 1, characterized in that, The imaging light of any of the color mixing ratios includes at least two different wavelengths, wherein the intensity of each wavelength can be adjusted when it is projected onto the coupling region (3).

3. The optical module according to claim 1, characterized in that, The coupling gratings are configured in a one-to-one correspondence with the wavelengths of the light emitted by the optomechanical unit (1), so that each coupling grating can couple in a wavelength of light. Any one of the coupling gratings in the coupling region (3) has at least one coupling grating in the coupling region (4) corresponding to the coupling grating, and light rays coupled in from one of the coupling gratings can be coupled out through at least one coupling grating corresponding to the coupling grating.

4. The optical module according to claim 1, characterized in that, By adjusting at least one of the grating parameters, such as the grating period, duty cycle, groove depth, and sidewall tilt angle of the coupled-in grating and the coupled-out grating, it is possible to form at least two coupled-in gratings with different grating structures in the coupled-in region (3), at least two coupled-out gratings with different grating structures in the coupled-out region (4), and to ensure that each coupled-in grating has at least one coupled-out grating corresponding to it in the coupled-out region (4).

5. The optical module according to claim 1, characterized in that, The light guiding device is a diffractive waveguide device.

6. The optical module according to claim 1, characterized in that, The light emitted by the optical engine (1) includes red light, green light and blue light; The coupling region (3) includes a first coupling grating (31), a second coupling grating (32) and a third coupling grating (33); The coupling region (4) includes a first coupling grating (41), a second coupling grating (42) and a third coupling grating (43), and the first coupling grating (41), the second coupling grating (42) and the third coupling grating (43) are respectively configured as multiple; The first coupling grating (31) is used to couple in red light, and the first coupling grating (31) corresponds to the first coupling out grating (41); The second coupling grating (32) is used to couple in green light, and the second coupling grating (32) corresponds to the second coupling out grating (42); The third coupling grating (33) is used to couple in blue light, and the third coupling grating (33) corresponds to the third coupling out grating (43).

7. The optical module according to claim 6, characterized in that, The red light emitted by the optical engine (1) is coupled into the transparent substrate (2) through the first coupling grating (31) and propagated to the coupling region (4) by total internal reflection. The light can be coupled out through all the first coupling gratings (41) at the position of the coupling region (4). The green light emitted by the optical engine (1) is coupled into the transparent substrate (2) through the second coupling grating (32) and propagated to the coupling region (4) by total internal reflection. The light can be coupled out through all the second coupling gratings (42) at the position of the coupling region (4). The blue light emitted by the optical engine (1) is coupled into the transparent substrate (2) through the third coupling grating (33) and propagated to the coupling region (4) by total internal reflection. The light can be coupled out through all the third coupling gratings (43) at the position of the coupling region (4).

8. A head-mounted display device, characterized in that, include: case; as well as The optical module as described in any one of claims 1-7.

9. The head-mounted display device according to claim 8, characterized in that, The head-mounted display device is smart glasses or a smart helmet, and includes: A front frame assembly, wherein a left lens mounting portion and a right lens mounting portion are provided on the front frame assembly, and a bridge portion is provided between the left lens mounting portion and the right lens mounting portion; The optical module is configured as two: One of the optical modules has a transparent substrate (2) disposed in the left lens mounting portion, and the optical engine (1) of the optical module is disposed at the end of the left lens mounting portion away from the bridge of the nose and is opposite to the coupling area (3) on the transparent substrate (2), and the coupling area (4) on the transparent substrate (2) is opposite to the user's left eye. Another transparent substrate (2) of the optical module is disposed in the right lens mounting part, and the optical engine (1) of the optical module is disposed at one end of the right lens mounting part away from the bridge of the nose and opposite to the coupling area (3) on the transparent substrate (2), and the coupling area (4) on the transparent substrate (2) is opposite to the user's right eye.

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