Diffuser Plate Devices and Their Fabrication Methods

Abstract

The application provides a diffusion plate device. The diffusion plate device comprises a substrate and a microlens array, the microlens array comprises multiple rows and multiple columns of microlenses arranged on the surface of the substrate, the microlenses comprise a first axis and a second axis perpendicular to each other, and the first axis and the second axis are located in a plane parallel to the substrate, wherein the first axes of the multiple microlenses are at different angles, the radii of curvature of the multiple microlenses are different, so that the maximum heights of the multiple microlenses are different, the spacing between each row of microlenses is equal, and the spacing between each column of microlenses is equal. The diffusion plate device provided by the application can greatly suppress the speckle effect in the imaging process by arranging the microlenses to rotate at a random angle around the central axis, can present a projection picture with high uniformity, and has simple and feasible processing technology.

Description

Technical Field

[0001] This application relates to the field of optical device design and manufacturing, and more specifically, to a diffuser plate device and its preparation method, a projection device, and a display device. Background Technology

[0002] Microlens array diffusers are commonly used as screens in head-up display (HUD) systems, projectors, and other similar devices. Compared to traditional frosted glass diffusers, microlens diffusers offer unique advantages in terms of controllable diffusion angle, uniformity of the diffused light field, and clarity. With the development of the HUD market, increasingly higher demands are being placed on the resolution and clarity of HUD products, leading to higher requirements for the accompanying Picture Generating Unit (PGU). MEMS-PGU (Micro Electromechanical System-Picture Generating Unit), as a high-resolution PGU solution, will see increasingly widespread application in the future.

[0003] refer to Figure 1 Since the light source of MEMS-PGU is a laser source, the interference caused by the strong coherence of the laser will easily produce speckle effect when ordinary microstructure diffuser plates are composed of a series of identical microstructure arrays and applied to HUD systems with such laser sources, thus reducing the uniformity of the image.

[0004] The industry needs a device with a simple structure that can overcome the above technical challenges and enable diffuser plates to achieve highly uniform projection images when applied to HUDs with laser light sources. Summary of the Invention

[0005] This application provides a diffuser plate device and its fabrication method that can at least partially solve the above-mentioned problems existing in related technologies.

[0006] This application provides a diffuser plate device, comprising: a substrate; and a microlens array, the microlens array including multiple rows and multiple columns of microlenses disposed on the surface of the substrate, each microlens including a first axis and a second axis perpendicular to each other, the first axis and the second axis being located in a plane parallel to the substrate, wherein the first axes of the multiple microlenses are at different angles, the radii of curvature of the multiple microlenses are different such that the maximum height of the multiple microlenses is different, and the spacing between each row of microlenses is equal, and the spacing between each column of microlenses is equal.

[0007] In one embodiment, the material of the substrate includes at least one of glass and plastic.

[0008] In one embodiment, the material of the plurality of microlenses includes at least one of adhesive and glass.

[0009] In one embodiment, the central axes of the plurality of microlenses form a quadrilateral array, and there are no gaps between the plurality of microlenses.

[0010] In one embodiment, the angle between the first axis and the row direction of the microlens array is 0 to 90°.

[0011] In one embodiment, the curvature C of the surface profile of the microlens in the direction of its first axis x The mean C of the curvature of the plurality of microlenses in the direction of their respective first axes x0 Satisfy C x =C x0 ±5%; the curvature C of the surface profile of the microlens in the direction of its second axis. y The mean C of the curvature of the plurality of microlenses in the direction of their respective second axes y0 Satisfy C y =C y0 ±5%.

[0012] Another aspect of this application provides a method for manufacturing a diffuser plate device, comprising the following steps: disposing a microlens array on the surface of a substrate, the microlens array comprising multiple rows and multiple columns of microlenses; wherein multiple microlenses are rotated at different angles about their respective central axes, the radii of curvature of the multiple microlenses are different, such that the heights of the highest points of the multiple microlenses are different, and the spacing between each row of microlenses is equal, and the spacing between each column of microlenses is equal.

[0013] In one embodiment, the material of the substrate includes at least one of glass and plastic.

[0014] In one embodiment, the material of the plurality of microlenses includes at least one of adhesive and glass.

[0015] In one embodiment, the central axes of the plurality of microlenses form a quadrilateral array, and there are no gaps between the plurality of microlenses.

[0016] In one embodiment, the plurality of microlenses rotate about their respective central axes in the range of 0 to 90°.

[0017] In one embodiment, the curvature C of the surface profile of the microlens in the direction of its first axis x The mean C of the curvature of the plurality of microlenses in the direction of their respective first axes x0Satisfy C x =C x0 ±5%; the curvature C of the surface profile of the microlens in the direction of its second axis. y The mean C of the curvature of the plurality of microlenses in the direction of their respective second axes y0 Satisfy C y =C y0 ±5%.

[0018] Another aspect of this application provides a projection device, the electronic device including a diffuser plate device as described in any of the preceding claims.

[0019] Another aspect of this application provides a display device, the electronic device including a diffuser plate device as described in any of the preceding claims.

[0020] According to an embodiment of this application, the diffuser plate device and its fabrication method can significantly suppress speckle effects during imaging by rotating the microlens around the central axis at random angles.

[0021] Furthermore, by setting the curvature radius of the microlenses to be random, it helps to present a highly uniform projected image.

[0022] Furthermore, the center points of the microlenses are arranged neatly with equal spacing between each row and column, making the processing technology of this application simple and feasible. Attached Figure Description

[0023] 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. Wherein:

[0024] Figure 1 This is a diffraction pattern of a common diffuser plate device in this field;

[0025] Figure 2 This is a schematic diagram of a diffuser plate device structure according to one embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the rotation direction of a microlens about a central axis according to one embodiment of this application;

[0027] Figure 4 yes Figure 3 A schematic outline of the microlens at section AA;

[0028] Figure 5 This is a schematic diagram of a microlens array structure according to one embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the diffuser plate device structure in Embodiment 1 of this application;

[0030] Figure 7This is the diffraction pattern of the diffuser device in Embodiment 1 of this application;

[0031] Figure 8 This is a schematic diagram of the diffuser plate device in Embodiment 2 of this application;

[0032] Figure 9 This is a diffraction pattern of the diffuser device in Embodiment 2 of this application. Detailed Implementation

[0033] 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.

[0034] 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, especially not any order of precedence. Therefore, without departing from the teachings of this application, the first part discussed herein may also be referred to as the second part, and vice versa.

[0035] In the accompanying drawings, the thickness, dimensions, and shapes of the parts have been slightly adjusted for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale. 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.

[0036] It should also be understood that expressions such as "comprising," "including," "having," "containing," and / or "comprising" are open-ended rather than closed-ended expressions in this specification, indicating the presence of the stated features, elements, and / or components, but not excluding the presence 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 just 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 examples or illustrations.

[0037] 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.

[0038] 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.

[0039] Furthermore, when the term "connection" or "linkage" is used in this application, it may indicate direct or indirect contact between the corresponding components, unless otherwise expressly defined or deduced from the context.

[0040] Figure 2 This is a schematic diagram of the structure of a diffuser plate device according to one embodiment of this application, as shown below. Figure 2 As shown, the diffuser device includes a substrate 10 and a microlens array 20. The substrate 10 and the microlens array 20 can be integrally formed, or the microlens array 20 can be formed on the substrate 10.

[0041] The microlens array 20 includes a plurality of microlenses 21 disposed on the surface of the substrate 10 in an array configuration. Exemplarily, these microlenses may be arranged in a square configuration. In this embodiment, the horizontal direction can be considered the extension direction of rows, and the vertical direction the extension direction of columns.

[0042] refer to Figure 3 In this configuration, a straight line passing through the midpoint P of the microlens 21 and perpendicular to the substrate 10 is used as the central axis of the microlens 21. Multiple microlenses 21 rotate around their respective central axes at different angles, ranging from 0° to 90°. Furthermore, the surface shape of the microlens 21 includes a first axis x and a second axis y that are parallel to and perpendicular to each other in a plane parallel to the substrate 10. The first axis x of different microlenses 21 rotates around their respective central axes at different angles. Furthermore, the first axes x of multiple microlenses 21 are at different angles to each other. Furthermore, the first axes x of multiple microlenses 21 are at different angles within 90° to the extension direction X of the row.

[0043] In an exemplary embodiment, the radii of curvature of the plurality of microlenses 21 are different, so that the heights of the highest points of the plurality of microlenses 21 are different. Specifically, the radii of curvature of the surface features of the plurality of microlenses 21 in the direction of their respective first axis x are different, and the radii of curvature of the surface features of the plurality of microlenses 21 in the direction of their respective second axis y are different. Further, the radii of curvature of the surface features of the microlenses 21 in the direction of the first axis x are different from the radii of curvature in the direction of the second axis y.

[0044] In some embodiments, the microlens array 20 includes multiple rows and columns of microlenses 21, with equal spacing between each row and between each column. Exemplarily, the microlens array 20 can be quadrilateral; specifically, it can be a regular quadrilateral or rectangular array.

[0045] In some embodiments, the material of the substrate 10 may include, for example, glass or plastic.

[0046] In some embodiments, the material of the plurality of microlenses 21 may include, for example, adhesive or glass.

[0047] In some embodiments, the multiple microlenses 21 are integrally formed with the substrate 10, and the material is glass. In other embodiments, the multiple microlenses 21 made of adhesive material can be disposed on the plastic substrate 10.

[0048] In some embodiments, the surface profile of the microlens 21 satisfies the following formula:

[0049]

[0050] A three-dimensional rectangular coordinate system can be established using a surface parallel to the substrate 10 and passing through the midpoint P as a reference plane. The central axis of the microlens 21 (i.e., the midpoint P) can be used as the origin within this reference plane. z represents the height of a point on the surface of the microlens 21 from the reference plane, and r... x r represents the distance of a point from the central axis (midpoint P) along the first axis x-axis. y C represents the distance of a point from the central axis (midpoint P) in the direction of the second axis y. x C represents the curvature of the surface in the direction of the first axis x. y K represents the curvature of the surface in the direction of the second axis y. x K represents the conicity coefficient of the surface shape in the direction of the first axis x. y This represents the conicity coefficient of the surface shape in the direction of the second axis y.

[0051] refer to Figure 4 The curvature of the multiple microlenses 21 is equal to the average C of their respective curvatures along the first axis x direction. x0The mean C of the curvature in the second axis y-direction y0 Based on the reference, the curvature C of the microlens 21 in the direction of the first axis x is... x The range can be C x0 ±5%, the curvature C of microlens 21 in the direction of the second axis y y The range can be C y0 ±5%.

[0052] Example 1

[0053] Figure 6 This is a schematic diagram of a diffuser plate device according to one embodiment of this application. Figure 7 The diffraction pattern is shown for a diffuser plate device according to this application.

[0054] like Figure 5 As shown, a microlens array 20 is disposed on the surface of the substrate 10. The microlens array 20 can be a regular quadrilateral. Each microlens 21 can occupy a region, and these microlenses 21 form multiple rows or columns. The spacing between each row or column is equal. The material of the substrate 10 includes glass and plastic. The surface shape of the multiple microlenses 21 can satisfy the aforementioned formula (1), and the material includes adhesive and glass.

[0055] For example, the rotation angle of the plurality of microlenses 21 is between 0 and 90°; the length and width of the microlenses are both 50 μm.

[0056] In formula (1), the following parameters can be set as follows: the conic coefficient is -0.75; the radius of curvature of the surface in the direction of the first axis x is between 50±3μm; and the radius of curvature of the surface in the direction of the second axis y is between 90±3μm.

[0057] Figure 7 This is the speckle effect diagram of the random microlens array diffuser plate calculated using the angular spectrum propagation theory of diffraction in this embodiment. From Figure 1 and Figure 7 The comparison shows that the diffuser device in this embodiment can significantly suppress the speckle effect.

[0058] Example 2

[0059] Figure 8 This is a schematic diagram of a diffuser plate device according to one embodiment of this application. Figure 9 This is a diffraction pattern of the diffuser device according to this embodiment.

[0060] like Figure 8As shown, a microlens array 20 is disposed on the surface of the substrate 10, and the microlens array 20 can be a regular quadrilateral. Each microlens 21 can occupy a region, and these microlenses 21 form multiple rows or columns. The spacing between each row or column is equal. The material of the substrate 10 includes glass and plastic. The surface shape of the multiple microlenses 21 can satisfy the aforementioned formula (1), and the material includes adhesive and glass.

[0061] For example, the rotation angle of the plurality of microlenses 21 is between 0 and 40°; the length and width of the microlenses are both 40 μm.

[0062] In formula (1), the following parameters are set as follows: the conic coefficient is -0.75; the radius of curvature of the surface in the direction of the first axis x is between 50±3μm; and the radius of curvature of the surface in the direction of the second axis y is between 70±3μm.

[0063] Figure 9 This is the speckle effect diagram of the random microlens array diffuser plate calculated using the angular spectrum propagation theory of diffraction in this embodiment. From Figure 1 and Figure 9 The comparison shows that the diffuser device in this embodiment can significantly suppress the speckle effect.

[0064] According to at least one embodiment of this application, by using a structure in which the microlens rotates around the central axis at random angles and the curvature radius of the microlens 21 is randomly set, the speckle effect can be significantly suppressed during the imaging process, resulting in a highly uniform projected image.

[0065] Furthermore, the center points of the microlenses are arranged neatly with equal spacing between each row and column, making the processing technology of this application simple and feasible.

[0066] Another aspect of this application provides a method for manufacturing a diffuser plate device, comprising the following steps:

[0067] A microlens array is disposed on the surface of a substrate. The microlens array comprises multiple microlenses arranged in an array. The multiple microlenses are rotated at different angles around their respective central axes.

[0068] For example, multiple microlenses have different radii of curvature, so that the heights of the highest points (midpoints) of the multiple microlenses are different.

[0069] For example, a microlens array can be engraved using a laser.

[0070] Since the content and structure described above regarding the diffuser device structure can be fully or partially applied to the fabrication method described here, related or similar content will not be repeated.

[0071] Another aspect of this application provides a projection device, including the aforementioned diffuser plate device. This device is used to significantly suppress speckle effects during the imaging process, resulting in a highly uniform projected image.

[0072] Another aspect of this application provides a display device including the aforementioned diffuser plate device. This device is used to significantly suppress speckle effects during imaging, resulting in a highly uniform projected image.

[0073] The above description is merely an illustration of the embodiments of this application and 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 technical concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A diffuser plate device, characterized by, Comprising: a substrate; and a microlens array comprising a plurality of rows and a plurality of columns of microlenses disposed on a surface of the substrate, the microlenses having a face shape comprising a first axis and a second axis perpendicular to each other, the first axis and the second axis lying in a plane parallel to the substrate, wherein the first axis of a plurality of the microlenses forms a different angle with a row direction of the microlens array within 90°, the face shape of a plurality of the microlenses has a different radius of curvature in a direction of the respective first axis, and the face shape of a plurality of the microlenses has a different radius of curvature in a direction of the respective second axis, such that a plurality of the microlenses have different maximum heights, and a spacing between each row of the microlenses is equal, and a spacing between each column of the microlenses is equal.

2. The diffuser device of claim 1, wherein: a material of the substrate comprises at least one of glass and plastic.

3. The diffuser device of claim 1, wherein: a material of a plurality of the microlenses comprises at least one of glue and glass.

4. The diffuser plate device of claim 1, wherein a plurality of the microlenses have their center axes forming a quadrilateral array, and there is no gap between a plurality of the microlenses.

5. The diffuser device of claim 1, comprising: a curvature of the surface shape of the microlens in the direction of the first axis thereof a mean value of the curvatures of the plurality of microlenses in the direction of the respective first axes satisfies ; the curvature of the surface shape of the microlenses in the direction of the second axis thereof the average of the curvatures of the plurality of microlenses in the direction of the respective second axes satisfies .

6. A method for manufacturing a diffuser plate device, characterized by, a step of: disposing a microlens array on a surface of a substrate, the microlens array comprising a plurality of rows and a plurality of columns of microlenses, the microlenses having a face shape comprising a first axis and a second axis perpendicular to each other, the first axis and the second axis lying in a plane parallel to the substrate; wherein a plurality of the microlenses are rotated by different angles about their respective center axes, the first axis of a plurality of the microlenses forms a different angle with a row direction of the microlens array within 90°, the face shape of a plurality of the microlenses has a different radius of curvature in a direction of the respective first axis, and the face shape of a plurality of the microlenses has a different radius of curvature in a direction of the respective second axis, such that a plurality of the microlenses have different maximum heights, and a spacing between each row of the microlenses is equal, and a spacing between each column of the microlenses is equal.

7. The method of claim 6, wherein: a material of the substrate comprises at least one of glass and plastic.

8. The method of claim 6, wherein: a material of a plurality of the microlenses comprises at least one of glue and glass.

9. The method of claim 6, wherein: a plurality of the microlenses have their center axes forming a quadrilateral array, and there is no gap between a plurality of the microlenses.

10. The method of claim 9, comprising: a curvature of the surface shape of the microlens in the direction of the first axis thereof a mean value of the curvatures of the plurality of microlenses in the direction of the respective first axes satisfies ; the curvature of the surface shape of the microlenses in the direction of the second axis thereof the average of the curvatures of the plurality of microlenses in the direction of the respective second axes satisfies .

11. A projection apparatus, characterized by comprising: the diffuser device of any one of claims 1 to 5.

12. A display device comprising: the diffuser device of any one of claims 1 to 5.

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