Optical assembly, projection system and projection method

Abstract

The application provides an optical assembly, a projection system and a projection method. The optical assembly comprises: a first diffraction element, which is divided into at least two first diffraction regions, each of which comprises a plurality of first microstructures carrying image information, wherein the height distribution of the plurality of first microstructures included in different first diffraction regions on the optical axis is different; and a second diffraction element, which is arranged along the optical axis with the first diffraction element, the second diffraction element is divided into at least two second diffraction regions corresponding to the first diffraction regions, each of the second diffraction regions comprises at least one second microstructure with an inclined surface, wherein the inclined directions of the inclined surfaces of the second microstructures included in different second diffraction regions are different.

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to an optical assembly, a projection system, and a projection method. Background Technology

[0002] Diffractive optical elements (DOEs) are gaining increasing attention in projection systems due to their high diffraction efficiency, small size, light weight, and ease of fabrication.

[0003] The projection angle of a traditional DOE projection system is mainly determined by the size of the DOE's microstructure. The size of the microstructure is usually on the micrometer scale. Larger projection angles require smaller microstructures, resulting in complex designs, difficult actual manufacturing, and higher costs. In practical applications, large-angle projected images are typically projected by stitching together multiple DOEs with microstructures and multiple light sources. However, this method is difficult to assemble and has a high overall cost. Summary of the Invention

[0004] One aspect of this application provides an optical component, comprising: a first diffraction element divided into at least two first diffraction regions, each first diffraction region including a plurality of first microstructures carrying image information, wherein the height distribution of the plurality of first microstructures included in different first diffraction regions is different along the optical axis; and a second diffraction element disposed along the optical axis with the first diffraction element, the second diffraction element being divided into at least two second diffraction regions corresponding to the first diffraction regions, each second diffraction region including at least one second microstructure with a slope, wherein the slope direction of the second microstructure included in different second diffraction regions is different.

[0005] In one embodiment of this application, the first diffraction region and the second diffraction region have the same shape and size, and their centers are aligned.

[0006] In one embodiment of this application, the first diffraction element includes N×M first diffraction regions, and the second diffraction element includes N×M second diffraction regions.

[0007] In one embodiment of this application, the first diffraction region and the second diffraction region are rectangular in shape, and N ≤ 3 and are positive integers, and M ≤ 3 and are positive integers.

[0008] In one embodiment of this application, the first microstructure in each of the first diffraction regions has a height distribution of 2n heights on the optical axis, where n≥3.

[0009] In one embodiment of this application, the first microstructures included in different first diffraction regions have the same 2n height values.

[0010] In one embodiment of this application, the first microstructure has a first size and a second size in a first direction and a second direction perpendicular to the optical axis, respectively, which satisfy the following conditions with respect to the wavelength λ of the light beam projected onto the optical component: the first size ≥ 5λ and the second size ≥ 5λ.

[0011] In one embodiment of this application, the first size is ≥2μm and the second size is ≥2μm.

[0012] In one embodiment of this application, the outline shape of the first microstructure is a prism.

[0013] In one embodiment of this application, the optical component further includes a substrate for supporting at least one of the first diffraction element and the second diffraction element.

[0014] In one embodiment of this application, the substrate includes: a first substrate, wherein the first diffraction element and the second diffraction element are respectively located on opposite sides of the first substrate.

[0015] In one embodiment of this application, the first substrate bondes the first diffraction element and the second diffraction element together as a single unit.

[0016] In one embodiment of this application, the substrate further includes a second substrate located on the side of the first diffraction element opposite to the first substrate.

[0017] In one embodiment of this application, the first diffraction element and the second diffraction element are disposed separately.

[0018] In one embodiment of this application, the substrate comprises at least one of plastic or glass.

[0019] In one embodiment of this application, the first diffraction element and the second diffraction element comprise at least one of glass or resin.

[0020] Another aspect of this application provides a projection system, comprising: an optical component as described in any of the preceding claims; a light source for projecting the light beam onto the surface of the optical component; and a projection surface disposed on the light-emitting side of the optical component, comprising at least two projection areas, wherein the projection areas are used to receive the light beam having a preset deflection angle and carrying the image information diffracted via corresponding first and second diffraction areas.

[0021] In one embodiment of this application, the preset deflection angle is ≤20°.

[0022] In one embodiment of this application, the center of the light source, the center of the first diffraction element, and the center of the second diffraction element are aligned.

[0023] In one embodiment of this application, the light source includes a laser.

[0024] Another aspect of this application provides a method for projecting an image using the optical component described in any of the preceding claims, comprising: configuring a light source for emitting a light beam; configuring the optical component for receiving the light beam on the light-emitting side of the light source; and configuring a projection surface having at least two projection areas at a predetermined distance from the light-emitting side of the optical component, wherein the projection areas are used to receive the light beam having a predetermined deflection angle and carrying the image information, diffracted via corresponding first and second diffraction areas.

[0025] In one embodiment of this application, the preset deflection angle is ≤20°.

[0026] The optical component provided in this application can enlarge the projected image by stitching together the projected images of each region and expanding the projection angle through a second diffraction region set in the first diffraction region without reducing the pixel size (first microstructure size). Attached Figure Description

[0027] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 A schematic structural diagram of an optical component according to Embodiment 1 of this application is shown;

[0029] Figure 2 A schematic diagram of the first diffraction region according to Embodiment 1 of this application is shown;

[0030] Figure 3 A projection schematic diagram according to Embodiment 1 of this application is shown;

[0031] Figure 4 A schematic structural diagram of a projection system according to Embodiment 1 of this application is shown;

[0032] Figure 5 A schematic diagram of the offset of the projected image according to Embodiment 1 of this application is shown;

[0033] Figure 6 A flowchart of the projection method of Embodiment 1 of the fundamental application is shown.

[0034] Figure 7 A schematic structural diagram of an optical component according to Embodiment 2 of this application is shown;

[0035] Figure 8 A schematic structural diagram of an optical component according to Embodiment 3 of this application is shown. Detailed Implementation

[0036] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first microstructure ring discussed below may also be referred to as a second first microstructure ring, and vice versa.

[0038] In the accompanying drawings, the thickness, dimensions, and shapes of the components have been slightly adjusted for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale. For example, the height of the first microstructure ring relative to the thickness of the substrate is not proportional to actual production. As used herein, the terms “approximately,” “about,” and similar terms are used as expressions of approximation, not as expressions of degree, and are intended to illustrate inherent deviations in measured or calculated values ​​that will be recognized by one of ordinary skill in the art.

[0039] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0040] Unless otherwise specified, all terms used herein (including engineering and technical terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that, unless expressly stated herein, terms defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or overly formalized meaning.

[0041] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Furthermore, unless explicitly limited or contradicted by the context, the specific steps included in the methods described in this application are not limited to the order in which they are described, but can be performed in any order or in parallel. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] This application provides an optical component, including a first diffraction element and a second diffraction element. The first diffraction element is divided into at least two first diffraction regions, each first diffraction region including multiple first microstructures carrying image information, wherein the height distribution of the multiple first microstructures in different first diffraction regions is different along the optical axis. The second diffraction element is disposed along the optical axis with the first diffraction element, and the second diffraction element is divided into at least two second diffraction regions corresponding to the first diffraction regions. Each second diffraction region includes at least one second microstructure with a slope, wherein the slope direction of the second microstructure in different second diffraction regions is different, thereby the second diffraction elements in different second diffraction regions have different phases.

[0043] Optionally, the corresponding first and second diffraction regions have the same shape and size, and their centers are aligned. In some examples, the first diffraction element includes N×M first diffraction regions, and the second diffraction element also includes corresponding N×M second diffraction regions. The shapes of the first and second diffraction regions can be rectangular. Optionally, N ≤ 3 and M ≤ 3 in the aforementioned N×M first and N×M second diffraction regions, and both N and M are positive integers.

[0044] In some examples, the first microstructure within each first diffraction region has 2 on the optical axis. n The height distribution of each height, where n≥3. The different first diffraction regions include first microstructures with 2 n All heights have the same height value.

[0045] In some examples, the first microstructure has a first size and a second size in a first direction and a second direction perpendicular to the optical axis, respectively. The first size and the second size satisfy the following conditions with respect to the wavelength λ of the light beam projected onto the optical component: the first size ≥ 5λ and the second size ≥ 5λ. Optionally, the first size ≥ 2μm and the second size ≥ 2μm.

[0046] In some examples, the outline shape of the first microstructure is a prism.

[0047] In some examples, the optical assembly further includes a substrate for supporting at least one of the first and second diffraction elements. Optionally, the substrate may include a first substrate, with the first and second diffraction elements located on opposite sides of the first substrate, respectively. In examples where the optical assembly includes only the first substrate, the first substrate may be used to bond the first and second diffraction elements together.

[0048] Optionally, the substrate may further include a second substrate. In an example where the optical component includes a first substrate and a second substrate, the second substrate may be located on the side of the first diffraction element opposite to the first substrate, so that the first substrate and the second substrate can be used to support the second diffraction element and the first diffraction element, respectively, and the first diffraction element and the second diffraction element can be disposed separately. In this example, the second diffraction element and the first diffraction element are located on the same side of the second substrate, and substrates are provided on both sides of the first diffraction element, thereby protecting the first microstructure of the first diffraction element.

[0049] Optionally, the substrate described above includes at least one of plastic or glass. Optionally, the first and second diffraction elements described above include at least one of glass or resin.

[0050] Embodiments of this application also provide a projection system, including a light source, a projection surface, and the optical components described above. The light source projects a light beam onto the area of ​​a first diffraction element carrying image information. The projection surface is disposed on the light-emitting side of the optical component and is used to receive the light beam carrying image information projected by the optical component, thereby forming a projected image. The centers of the light source, the first diffraction element, and the second diffraction element are aligned with each other to improve the clarity of the projected image.

[0051] In some examples, the projection surface may include at least two projection regions corresponding to the first and second diffraction regions. Each projection region can receive a beam of light diffracted from the corresponding first and second diffraction regions, having a preset deflection angle and carrying image information. The optical component provided in this application includes regionalized first and second diffraction elements. The first diffraction element carries image information, and the inclination directions of the inclined surfaces of the second microstructures included in different second diffraction regions are different, resulting in different phases of the second diffraction elements in different second diffraction regions. This causes a change in the direction of the projected image after the beam passes through the first diffraction element and different second diffraction regions. Therefore, the embodiments of this application can increase the projection angle without reducing the pixel size (first microstructure size), thereby increasing the size of the projected image. Furthermore, the optical component provided in this application can ensure that the projected image size meets requirements when a large pixel unit is required by setting a second diffraction region corresponding to the first diffraction region.

[0052] The following combination Figures 1-8 The implementation methods provided in this application are described in detail.

[0053] Implementation Method 1

[0054] Figure 1 This is a schematic structural diagram of the optical components according to this embodiment. (Reference) Figure 1 The optical component 1 in this embodiment includes a first diffraction element 10. The first diffraction element 10 is divided into two first diffraction regions, namely a first diffraction region 11 and a first diffraction region 12, and the shape of each first diffraction region can be... Figure 2 The rectangle shown. Optionally, each first diffraction region may include multiple first microstructures 101 carrying image information. The outline shape of the first microstructure 101 may be a prism, and the sides of adjacent first microstructures 101 are closely fitted.

[0055] Those skilled in the art should understand that the first diffraction element 10 can be divided into more than two first diffraction regions according to N×M, where N≤3 and is a positive integer, and M≤3 and is a positive integer.

[0056] For example, the height distribution and phase distribution of the first microstructure 101 in each first diffraction region along the optical axis are related. The phase distribution of the first microstructure 101 in the first diffraction regions 11 and 12 can be obtained by a phase retrieval algorithm, such as the GS algorithm and the simulated annealing algorithm. The phase gradient is 2. n n≥3 and a positive integer, the phase pairs of each microstructure 101 are 2π / 2 n Rounding down. Taking n=3 as an example, the phase of the first microstructure 101 has eight gradients, as shown in equation (1):

[0057]

[0058] Where x and y are the spatial coordinate distributions of the surface of the first diffraction element 10. The phase distribution obtained through the phase retrieval algorithm, The phase is the gradient, and mod is the modulo operation.

[0059] The height distribution of the first microstructure 101 can be obtained from the phase calculated in equation (1), as shown in equation (2):

[0060]

[0061] Where λ is the wavelength of the incident light projected onto optical component 1, and n(λ) is the refractive index of the first microstructure 101. Correspondingly, the height of the first microstructure 101 along the optical axis of the incident light can have eight gradient height values, which can balance diffraction efficiency while satisfying manufacturability. The height distribution of the first microstructure 101 with eight gradient height values ​​is different in the first diffraction region 11 and the first diffraction region 12.

[0062] Continue to refer to Figure 1 For example, the first microstructure 101 has a first size and a second size in a first direction (e.g., the x direction) and a second direction (e.g., the y direction) perpendicular to the optical axis (e.g., the z direction), respectively. The second size and the second size satisfy the following conditions with respect to the wavelength λ of the incident light: the first size ≥ 5λ, and the second size ≥ 5λ. Specifically, the second size ≥ 2μm, and the second size ≥ 2μm, can achieve diffraction efficiency ≥ 95% while improving the allowable range of processing errors.

[0063] The relationship between the pixel size of each first diffraction region (e.g., diffraction region 11 or diffraction region 12) of the first diffraction element 10 and the pixel size of the projected image is shown in equation (3):

[0064]

[0065]

[0066] Where z is the projection distance (i.e., the distance between the center of the optical component 10 and the center of the projection surface 5), n1×m1 is the number of pixels (i.e., the number of first microstructures in each first diffraction region 10, such as first diffraction region 11 or first diffraction region 12) of the first diffraction element 10, pixel_targe_x is the pixel size of the projected image in the x direction, pixel_targe_y is the pixel size of the projected image in the y direction, pixel_DOE_x is the pixel size of each first diffraction region of the first diffraction element 10 in the x direction (i.e., the first dimension of the first microstructure 101 in the x direction), and pixel_DOE_y is the pixel size of each first diffraction region of the first diffraction element 10 in the y direction (i.e., the second dimension of the first microstructure 101 in the y direction).

[0067] Continue to refer to Figure 1 The optical component 1 further includes a second diffraction element 20, which is arranged along the optical axis with the first diffraction element 10. The second diffraction element can be divided into two second diffraction regions corresponding to the first diffraction region. For example, the two second diffraction regions include a second diffraction region 21 corresponding to the first diffraction region 11 and a second diffraction region 22 corresponding to the first diffraction region 12. Optionally, the first diffraction region 11 and the second diffraction region 21 have the same shape and size, and their centers are aligned. Optionally, the first diffraction region 12 and the second diffraction region 22 have the same shape and size, and their centers are aligned. Each second diffraction region may include multiple second microstructures 102 with inclined surfaces, wherein the inclination directions of the inclined surfaces of the second microstructures 102 included in the second diffraction region 21 and the second diffraction region 22 are different. Optionally, the second diffraction element 20 may be a grating, which may further be a blazed grating.

[0068] Figure 3 This is a projected schematic diagram of this embodiment. (Reference) Figure 3 The incident light is projected from the light source 4 toward the optical component 1 in the direction indicated by the arrow, and the beam of incident light passes sequentially through the first diffraction element 10 and the second diffraction element 20. In the example where the second diffraction element 20 is a blazed grating, the second microstructure 102 of the second diffraction region 21 and the second diffraction region 22 may have blaze angles with different tilt directions (i.e., the tilt directions of the inclined planes described above are different).

[0069] Since the second microstructures 102 in different second diffraction regions can have different blaze angles, the phases of different second diffraction regions are different, and the projected images of each region of the second diffraction element 20 are deflected toward their respective target directions. Optionally, in such cases... Figure 3In the projection schematic shown, the second diffraction element 20 is, for example, a blazed grating. The projected images diffracted from different second diffraction regions can produce a deflection angle with the same magnitude as the blaze angle of their respective regions (e.g., Figure 5 The deflection angle θ in the image allows for the stitching of projected images from different projection regions, and also increases the size of the projected image. Optionally, the inclined surfaces of the second microstructure 102 included in the second diffraction region 21 and the second diffraction region 22 can be perpendicular to the direction of the projected image projected from their respective regions.

[0070] Those skilled in the art should understand that the second diffraction element 20 can be divided into more than two second diffraction regions according to N×M, where N≤3, M≤3, and N and M are both positive integers. Furthermore, those skilled in the art should also understand that the incident light can be projected from one side of the second diffraction element 20 onto the optical assembly 1, and sequentially pass through the second diffraction element 20 and the first diffraction element 10; this application does not limit this.

[0071] Continue to refer to Figure 1 The optical assembly 1 further includes a first substrate 30 for supporting the second diffraction element 20 and the first diffraction element 10, with the first diffraction element 10 and the second diffraction element 20 located on opposite sides of the first substrate 30. The material of the first substrate 30 may include, for example, plastic or glass. The material of the first diffraction element 10 may include, for example, glass or resin, and the material of the second diffraction element 20 may be the same as that of the first diffraction element 10. The first diffraction element 10, the second diffraction element 20, and the first substrate 30 may be an integral structure.

[0072] In some manufacturing processes, a first diffraction element 10 and a second diffraction element 20 can be formed on opposite sides of a glass substrate or resin substrate by sequential photolithography and etching processes. Optionally, the first diffraction element 10 and the second diffraction element 20 can also be formed on opposite sides of a glass substrate or resin substrate by nanoimprint lithography.

[0073] In other manufacturing processes, a first diffraction element 10 and a second diffraction element 20 can be formed separately, and then the center of the first diffraction region included in the first diffraction element 10 and the center of the second diffraction region included in the second diffraction element 20 are aligned one by one and attached to the first substrate 101 to form an optical component 1.

[0074] This embodiment also provides a projection system. Figure 4 This is a schematic diagram of the projection system 100 according to this embodiment. (Reference) Figure 4The projection system 100 includes a light source 4, a projection surface 5, and the optical component 1 described above. The light source 4 includes, for example, a laser, which can be used to project a light beam onto the surface of the optical component 1 carrying image information. The projection surface 5 is positioned at a predetermined distance (i.e., the projection distance z described below) from the light-emitting side of the optical component 1 and is used to receive the light beam carrying image information projected by the optical component, thereby forming a projected image. Optionally, the centers of the light source 4 and the optical component 1 (the centers of the first diffraction element 10 and the second diffraction element 20) are aligned to improve the sharpness of the projected image.

[0075] In some examples, the projection surface 5 may include the first diffraction region and the second diffraction region (collectively referred to as the projection region, e.g.) Figure 4 The projection areas 14 and 15 shown correspond to at least two projection areas, such as projection area 51 and projection area 52. Projection area 51 and projection area 52 can respectively receive light beams with preset deflection angles and carrying image information diffracted through the corresponding first and second diffraction areas.

[0076] In the example where the second diffraction element 20 is a grating, taking the second diffraction element 20 as having two second diffraction regions as an example, the phase of the second diffraction element 20 is as shown in equation (4):

[0077]

[0078] Where T is the period of the second diffraction element 20, mod is the remainder operation, b and c are the vectors of the second diffraction element, and x and y are the planar coordinate distributions of the second diffraction element 20. T satisfies the relationship T = λ / sinθ with the preset deflection angle θ. Therefore, by setting a reasonable period T through a preset deflection angle θ (e.g., θ ≤ 20°), the manufacturability of the second diffraction element 20 can be ensured, and splicing stripes can be avoided while realizing the splicing and magnification of the projected image.

[0079] For each projection region, the phase change of the incident light after passing through that region satisfies equation (5):

[0080]

[0081] As can be seen from equation (5), the phase of the incident light changes after passing through the first diffraction element 10 and the second diffraction element 20.

[0082] Figure 5 This is a schematic diagram of the projected image offset in this embodiment. (Reference) Figure 5 The center O of projection area 51 11The optical axis is deflected by a deflection angle θ relative to the center O1 of the projection area 14. The deflection angle θ is calculated as shown in equation (6):

[0083]

[0084] Where Dx is the dimension of optical component 1 in the x-direction, Lx is the dimension of projection surface 5 in the x-direction, and z is the projection distance. As shown in equation (6), the deflection angle θ is determined by the dimension of projection surface 5, the projection distance z, and the dimension of the projection area. Given a fixed dimension of optical component 1, the dimension of the projection area is related to the number of regions it is divided into. The number of regions in the projection area is consistent with the number of regions in the first and second diffraction areas.

[0085] In some examples, the wavelength λ of the incident light can be 633 nm. The first diffraction region 11 and the first diffraction region 12 can each include 500 × 500 first microstructures 101, that is, each first diffraction region includes 500 × 500 pixels, and the size of each pixel is 2 μm × 2 μm (that is, the size of the first microstructure 101 in the x and y directions is 2 μm respectively). The refractive index n of the first diffraction element 10 is 1.5. The period T of the second diffraction element is 4.075, the projection distance z is 500 mm, Dx is 2 mm, Dy is 1 mm; Lx is 316.5 mm, Ly is 158.25 mm.

[0086] For projection area 14 (including, as shown in the image) Figure 1 The first diffraction region 11 and the second diffraction region 21 shown are given. In equation (4), b = 1 and c = 0. For the projection region 15 (including the first diffraction region 11 and the second diffraction region 21 shown), b = 1 and c = 0. Figure 1 The first diffraction region 12 and the second diffraction region 22 are shown. In equation (4), b = -1 and c = 0. Therefore, the images of projection region 51 and projection region 52 have opposite deflections in the x-direction. This allows the projected images to be stitched together into a larger image, which can double the projection angle in the x-direction while keeping the size of the first microstructure 101 of the first diffraction element 10 unchanged.

[0087] This embodiment also provides a method for projecting images. Figure 6 This is a flowchart of the projection method in this embodiment. (Reference) Figure 6 The method 300 for projecting images in this embodiment includes:

[0088] 310. Configure a light source for emitting a beam of light;

[0089] 320. An optical component for receiving the light beam is disposed on the light-emitting side of the light source;

[0090] 330. A projection surface having at least two projection areas is disposed at a preset distance from the light-emitting side of the optical component, wherein the projection areas are used to receive light beams with preset deflection angles and carrying image information diffracted through corresponding first and second diffraction areas.

[0091] Implementation Method 2

[0092] Figure 7 This is a schematic structural diagram of the optical component 2 in this embodiment. (Reference) Figure 7 The optical component 2 in this embodiment includes a first diffraction element 10. The first diffraction element 10 is divided into two rectangular first diffraction regions, such as first diffraction region 11 and first diffraction region 12. Optionally, each first diffraction region may include a plurality of first microstructures 101 carrying image information. The outline shape of the first microstructures 101 may be prism, and the sides of adjacent first microstructures 101 are closely fitted.

[0093] For example, the height of the first microstructure 101 along the optical axis of the incident light can have eight gradient height values, which can balance diffraction efficiency while satisfying processability. The height distribution of the first microstructure 101 with eight gradient height values ​​is different in the first diffraction region 11 and the first diffraction region 12.

[0094] Continue to refer to Figure 7 The optical component 2 further includes a second diffraction element 20, which is arranged along the optical axis with the first diffraction element 10. The second diffraction element 20 can be divided into two second diffraction regions corresponding to the first diffraction region. The two second diffraction regions include, for example, a second diffraction region 21 corresponding to the first diffraction region 11 and a second diffraction region 22 corresponding to the first diffraction region 12. The second diffraction element 20 is, for example, a wedge prism.

[0095] Unlike embodiment one, in the example where the second diffraction element 20 is a wedge prism, each second diffraction region of the second diffraction element 20 may include a second microstructure 201. The inclined surfaces of the second microstructure 201 included in the second diffraction regions 21 and 22 may have different tilt angles. Thus, the phases of different second diffraction regions are different, and the projected images projected from different second diffraction regions of the second diffraction element 20 are deflected toward their respective target directions, achieving the stitching of projected images from different regions and having the effect of enlarging the projected image. The phase of the second diffraction element 20 is shown in equation (7):

[0096]

[0097] Where T is the period of the second diffraction element, b and c are the vectors of the second diffraction element, and x and y are the planar coordinate distributions of the diffraction optical element.

[0098] Continue to refer to Figure 7 The optical assembly 1 further includes a first substrate 30 for supporting the second diffraction element 20 and the first diffraction element 10, with the first diffraction element 10 and the second diffraction element 20 located on opposite sides of the first substrate 30. The material of the first substrate 30 may include, for example, plastic or glass. The material of the first diffraction element 10 may include, for example, glass or resin, and the material of the second diffraction element 20 may be the same as that of the first diffraction element 10. Optionally, the first diffraction element 10, the second diffraction element 20, and the first substrate 30 may be an integral structure.

[0099] In some manufacturing processes, a first diffraction element 10 and a second diffraction element 20 can be formed on opposite sides of a glass substrate or resin substrate by sequentially performing photolithography and etching processes. Optionally, the aforementioned first diffraction element 10 and second diffraction element 20 can also be formed on opposite sides of a glass substrate or resin substrate by nanoimprint lithography.

[0100] In other manufacturing processes, a first diffraction element 10 and a second diffraction element 20 can be formed separately, and then the center of the first diffraction region included in the first diffraction element 10 and the center of the second diffraction region included in the second diffraction element 20 are aligned one by one and attached to the first substrate 101 to form an optical component 1.

[0101] Since the description of the construction and design of the first microstructure 101 of the first diffraction element 10 and the second microstructure 201 of the second diffraction element 20 in Embodiment 1, as well as the principle of realizing the deflection angle θ, can be partially or completely applied to this embodiment, the same or similar content as Embodiment 1 will not be repeated again.

[0102] Implementation Method 3

[0103] Figure 8 This is a schematic structural diagram of the optical component 3 in this embodiment. (Reference) Figure 8 The optical component 3 in this embodiment includes a first diffraction element 10. The first diffraction element 10 is divided into two rectangular first diffraction regions, such as first diffraction region 11 and first diffraction region 12. Optionally, each first diffraction region may include a plurality of first microstructures 101 carrying image information. The outline shape of the first microstructure 101 may be prism, and the sides of adjacent first microstructures 101 are closely fitted.

[0104] For example, the height of the first microstructure 101 along the optical axis of the incident light can have eight gradient height values, which can balance diffraction efficiency while satisfying processability. The height distribution of the first microstructure 101 with eight gradient height values ​​is different in the first diffraction region 11 and the first diffraction region 12.

[0105] Continue to refer to Figure 8 The optical component 2 further includes a second diffraction element 20, which is arranged along the optical axis with the first diffraction element 10. The second diffraction element 20 can be divided into two second diffraction regions corresponding to the first diffraction region. The two second diffraction regions include, for example, a second diffraction region 21 corresponding to the first diffraction region 11 and a second diffraction region 22 corresponding to the first diffraction region 12. The second diffraction element 20 is, for example, a grating, which can be further described as a blazed grating. Each second diffraction region of the second diffraction element 20 may include multiple second microstructures 201. The second microstructures 201 included in the second diffraction regions 21 and 22 have inclined surfaces (blaze angles) tilted in different directions. As a result, the phases of the different second diffraction regions are different, and the projected images of the different second diffraction regions are deflected towards their respective target directions, realizing the stitching of projected images of different regions and having the effect of increasing the size of the projected image.

[0106] Continue to refer to Figure 8 Unlike embodiment one, the optical component 3 includes a first substrate 30 and a second substrate 40, wherein the first substrate 30 is used to support the second diffraction element 20, and the second substrate 40 is used to support the first diffraction element 10. In other words, the second diffraction element 20 and the first diffraction element 10 are fabricated on different substrates, and the first diffraction element 10 and the second diffraction element 20 are disposed separately. Figure 8 As shown, the side of the first diffraction element 10 away from the second substrate 40 is attached to the first substrate 30, that is, both sides of the first diffraction element 10 are provided with substrates, thereby protecting the first microstructure 101 of the first diffraction element 10.

[0107] For example, the material of the first substrate 30 includes, for example, plastic or glass. The material of the first diffraction element 10 includes, for example, glass or resin, and the material of the second diffraction element 20 may be the same as the material of the first diffraction element 10.

[0108] In actual manufacturing processes, a first diffraction element 10 and a second diffraction element 20 can be formed on two substrates respectively using photolithography and etching processes. Then, the side of the first diffraction element 10 away from the second substrate 40 is bonded to the first substrate 30. During bonding, the center of the first diffraction region of the first diffraction element 10 is aligned with the center of the second diffraction region of the second diffraction element 20. Optionally, the first diffraction element 10 and the second diffraction element 20 can also be formed on opposite sides of a glass substrate or a resin substrate using nanoimprint lithography.

[0109] Since the description of the construction and design of the first microstructure 101 of the first diffraction element 10 and the second microstructure 201 of the second diffraction element 20 in Embodiment 1, as well as the principle of realizing the deflection angle θ, can be applied to this embodiment without distinction or completely, the same or similar content as Embodiment 1 will not be repeated again.

[0110] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of protection involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the described technical concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions in this application.

Claims

1. An optical component, characterized in that, include: A first diffraction element is divided into at least two first diffraction regions. Each first diffraction region includes multiple first microstructures carrying image information. The height distribution of the multiple first microstructures in different first diffraction regions along the optical axis is different. Different first diffraction regions respectively load different sub-image information of the complete projected image. A second diffraction element is disposed along the optical axis with the first diffraction element. The second diffraction element is divided into at least two second diffraction regions corresponding to the first diffraction region. Each second diffraction region includes at least one second microstructure with a slope. The slope of the second microstructure included in different second diffraction regions has a different inclination direction, so as to deflect the sub-image beam emitted from the first diffraction region to different projection regions of the projection surface, so that the sub-images are stitched together into the complete projection image. The light beam passes sequentially through the first diffraction element and the second diffraction element.

2. The optical component according to claim 1, wherein, The first diffraction region and the second diffraction region have the same shape and size, and their centers are aligned.

3. The optical component according to claim 1, wherein, The first diffraction element includes N×M first diffraction regions, and the second diffraction element includes N×M second diffraction regions.

4. The optical component according to claim 1, wherein, The first diffraction region and the second diffraction region are rectangular in shape, and N≤3 and are positive integers, M≤3 and are positive integers.

5. The optical component according to claim 1, wherein, The first microstructure within each of the first diffraction regions has 2 on the optical axis. n The height distribution of n is given by n ≥ 3.

6. The optical component according to claim 5, wherein, The different first diffraction regions include the first microstructure having 2 n All heights have the same height value.

7. The optical component according to claim 1, wherein, The first microstructure has a first dimension and a second dimension in a first direction and a second direction perpendicular to the optical axis, respectively, which satisfy the following conditions with respect to the wavelength λ of the light beam projected onto the optical component: the first dimension ≥ 5λ and the second dimension ≥ 5λ.

8. The optical component according to claim 7, wherein, The first dimension is ≥2μm, and the second dimension is ≥2μm.

9. The optical component according to claim 1, wherein, The outline shape of the first microstructure is a prism.

10. The optical component according to claim 1, further comprising: A substrate for supporting at least one of the first diffraction element and the second diffraction element.

11. The optical component according to claim 10, wherein, The substrate includes: A first substrate, wherein the first diffraction element and the second diffraction element are respectively located on opposite sides of the first substrate.

12. The optical component according to claim 11, wherein, The first substrate bondes the first diffraction element and the second diffraction element together as one unit.

13. The optical component according to claim 11, wherein, The substrate also includes: The second substrate is located on the side of the first diffraction element opposite to the first substrate.

14. The optical component according to claim 13, wherein, The first diffraction element and the second diffraction element are set separately.

15. The optical component according to claim 11, wherein, The substrate includes at least one of plastic or glass.

16. The optical component according to any one of claims 1-15, wherein, The first diffraction element and the second diffraction element comprise at least one of glass or resin.

17. A projection system, characterized in that, include: Optical components according to any one of claims 1-16; A light source for projecting the light beam onto the area of ​​the optical component; as well as The projection surface is located on the light-emitting side of the optical component and includes at least two projection areas. The projection area is used to receive the light beam with a preset deflection angle and carrying the image information, which is diffracted through the corresponding first diffraction area and the second diffraction area.

18. The projection system according to claim 17, wherein, The preset deflection angle is ≤20°. o .

19. The projection system according to claim 17, wherein, The center of the light source, the center of the first diffraction element, and the center of the second diffraction element are aligned.

20. The projection system according to claim 17, wherein, The light source includes a laser.

21. A method for projecting an image using an optical component as described in any one of claims 1-16, characterized in that, include: Configure a light source for emitting a beam of light; The optical component for receiving the light beam is configured on the light-emitting side of the light source; as well as A projection surface with at least two projection areas is configured at a predetermined distance from the light-emitting side of the optical component. The projection area is used to receive the light beam with a preset deflection angle and carrying the image information, which is diffracted through the corresponding first diffraction area and the second diffraction area.

22. The method according to claim 21, wherein, The preset deflection angle is ≤20°. o .

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