Light intensity homogenization system

Abstract

According to the spatial light intensity homogenization system provided by the invention, after parallel light entering the homogenization system sequentially passes through a first fly's-eye lens array, a second fly's-eye lens array, a first lens, a second lens and a third lens, tiny nonuniformity in each thin light beam range after passing through a differential lens group can be compensated for multiple times; according to the invention, light is effectively homogenized, so that required uniform energy can be obtained on an illumination surface, when parallel light changes within an incidence angle range of + / -0.4 degrees, the light intensity unevenness of the illumination surface within a light field range of 0.12 mm * 0.12 mm is lower than 0.2%, the displacement of the light field is smaller than 1 [mu] m, and the uniformity and stability of the light field are ensured.

Description

Technical Field

[0001] This application relates to the field of optics, specifically to a light intensity homogenization system. Background Technology

[0002] In traditional lighting systems, when the incident angle of spatial light changes, the size, position, and uniformity of the uniform light field on the illuminated surface will significantly change. Light intensity distribution uniformity refers to the distribution of light intensity at various points within the illuminated area; the better the uniformity, the better the lighting effect. The quality of light intensity distribution uniformity directly affects the observation and operation of the workpiece, influencing actual work efficiency and quality. For machine tool lighting, uneven light intensity distribution will inevitably lead to problems such as shadows and reflections in the working environment, affecting the work experience and operational effectiveness. Therefore, the uniformity of light distribution in a lighting system is a crucial indicator for evaluating lighting systems in practical use.

[0003] Therefore, how to achieve high uniformity of light intensity illumination on a small-sized illumination surface has become a focus of research in this field. Based on this, it is necessary to design an optical system that is simple in structure, highly integrated, stable, and capable of modulating multiple parameters to effectively improve the uniformity and stability of light intensity on the illumination surface. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a light intensity homogenization system.

[0005] On the one hand, this application provides a light intensity homogenization system, including a micromirror group and an integrating mirror group arranged along the incident light path direction.

[0006] The micro-mirror group includes a first compound eye lens array and a second compound eye lens array;

[0007] The first compound eye lens array is composed of a plurality of first compound eye lenses. The surface of the first compound eye lens facing the light source is convex, and the surface facing the illumination surface is flat. The radius of curvature of the convex surface of the first compound eye lens is 12-14 mm.

[0008] The second compound eye lens array is composed of a plurality of second compound eye lenses. The surface of the second compound eye lens facing the light source is a plane, and the surface facing the illumination surface is a convex surface. The radius of curvature of the convex surface of the second compound eye lens is the same as the radius of curvature of the convex surface of the first compound eye lens.

[0009] The integrating lens group includes a first lens, a second lens, and a third lens;

[0010] The first lens is a positive focal aspherical lens, both surfaces of the first lens are convex, the surface of the first lens facing the light source is an even-order aspherical surface, and the surface of the first lens facing the illumination surface is a standard spherical surface.

[0011] The second lens is a positive focal aspherical lens. The surface of the second lens facing the light source is convex, and the surface facing the illumination surface is concave. The surface of the second lens facing the light source is an even-order aspherical, and the surface of the second lens facing the illumination surface is a standard spherical.

[0012] The third lens is a positive focal spherical lens. The surface of the third lens facing the light source is convex, and the surface facing the illumination surface is concave. The radius of the surface of the third lens facing the light source is smaller than the radius of the surface facing the illumination surface.

[0013] In one possible implementation of this application, the materials of the first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are fused silica.

[0014] In one possible implementation of this application, the first compound eye lens and the second compound eye lens have the same focal length.

[0015] In one possible implementation of this application, the focal point of the first compound eye lens coincides with the optical center of the second compound eye lens.

[0016] In one possible implementation of this application, the focal lengths of the first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are respectively: f (Fly-Eye)1 =25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

[0017] In one possible implementation of this application, the first compound eye lens and the second compound eye lens are square with a size of 0.4mm × 0.4mm.

[0018] In one possible implementation of this application, the first compound eye lens array and the second compound eye lens array are arranged in a 51×51 array configuration.

[0019] In one possible implementation of this application, the thicknesses of the first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are 1mm to 3mm, 1mm to 3mm, 4mm to 5mm, and 2mm to 3mm, respectively.

[0020] In one possible implementation of this application, there is a first air gap between the first compound eye lens array and the second compound eye lens array, a second air gap between the second compound eye lens array and the first lens, a third air gap between the first lens and the second lens, a fourth air gap between the second lens and the third lens, and a fifth air gap between the third lens and the illumination surface.

[0021] In one possible implementation of this application, the thicknesses of the first air gap, the second air gap, the third air gap, the fourth air gap, and the fifth air gap are d1 = 27-29 mm, d2 = 2-4 mm, d3 = 2-4 mm, d4 = 0-1 mm, and d5 = 4-5 mm, respectively.

[0022] In one possible implementation of this application, the first lens and the second lens are aspherical glass lenses, and the rotation curve of the surface shape of the aspherical lens satisfies the following equation:

[0023]

[0024] Where c is the curvature of the aspherical lens surface, k is the coefficient of the quadratic curve of the aspherical lens surface, and a1 to a8 are the values ​​of the aspherical polynomial.

[0025] Based on the technical solutions described in any of the above aspects, the technical advantages of this application are as follows:

[0026] 1. The parallel light of the incident light intensity homogenization system passes through the first compound eye lens array, the second compound eye lens array, the first lens, the second lens, and the third lens in sequence. This allows the minute non-uniformities within each narrow beam range after passing through the micro-mirror group to be compensated multiple times, thereby achieving effective homogenization of the light and obtaining the required uniform energy on the illumination surface.

[0027] 2. When the parallel light varies within an incident angle range of ±0.4°, the uniformity of light intensity on the illuminating surface within a 0.12mm×0.12mm light field is less than 0.2%, and the displacement of the light field is less than 1µm, thus ensuring the uniformity and stability of the light field. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1This is a schematic diagram of the spatial light intensity homogenization system provided in one embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the structure of a compound eye lens array provided in one embodiment of this application;

[0031] Figure 3 This is a schematic diagram of the structure of a compound eye lens array provided in one embodiment of this application;

[0032] Figure 4 This is a schematic diagram of the system optical path of a spatial light intensity homogenization system provided in one embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the uniformity of the light field on the illumination surface of a spatial light intensity homogenization system provided in one embodiment of this application.

[0034] In the diagram: 1-Microscope group; 11-First compound eye lens array; 111-First compound eye lens; 12-Second compound eye lens array; 121-Second compound eye lens; 2-Integrating lens group; 21-First lens; 22-Second lens; 23-Third lens. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] 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 further defined and explained in subsequent figures.

[0038] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] It should be noted that, where there is no conflict, different features in the embodiments of this application can be combined with each other.

[0040] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0041] Please see Figure 1 This application provides a light intensity homogenization system, including a micromirror group 1 and an integrating mirror group 2 arranged along the incident light path direction.

[0042] The micro-lens group 1 includes a first compound eye lens array 11 and a second compound eye lens array 12;

[0043] Compound eye lens arrays, also known as microlens arrays, are formed by a series of small lens arrays. The homogenization of the beam in compound eye lenses is mainly achieved by the division and redistribution of the beam.

[0044] The first compound eye lens array 11 is composed of a plurality of first compound eye lenses 111. The surface of the first compound eye lens 111 facing the light source is convex, and the surface facing the illumination surface is flat. The radius of curvature of the convex surface of the first compound eye lens 111 is 12-14 mm.

[0045] The second compound eye lens array 12 is composed of a plurality of second compound eye lenses 121. The surface of the second compound eye lens 121 facing the light source is planar, and the surface facing the illumination surface is convex. The radius of curvature of the convex surface of the second compound eye lens 121 is the same as the radius of curvature of the convex surface of the second lens 22.

[0046] Here, the cross-sectional shapes of the first compound eye lens array 11 and the second compound eye lens array 12 can be varied, for example, they can be circular, elliptical, rectangular, or square. In this case, the shapes of the first compound eye lens 111 and the second compound eye lens 121 are the same as the cross-sectional shapes of the first compound eye lens array 11 and the second compound eye lens array 12. Please refer to [link to relevant documentation]. Figure 2 , Figure 3 As shown. Figure 2 , Figure 3An example is given where the first compound eye lens array 11 and the second compound eye lens array 12 are square and circular, respectively. In this case, the first compound eye lens 111 and the second compound eye lens 121 correspond to square and circular shapes, respectively.

[0047] The integrating lens group 2 includes a first lens 21, a second lens 22 and a third lens 23;

[0048] The first lens 21 is a positive focal aspherical lens. Both surfaces of the first lens 21 are convex. The surface of the first lens 21 facing the light source is an even-order aspherical surface, and the surface of the first lens 21 facing the illumination surface is a standard spherical surface.

[0049] The second lens 22 is a positive focal aspherical lens. The surface of the second lens 22 facing the light source is convex, and the surface facing the illumination surface is concave. The surface of the second lens 22 facing the light source is an even-order aspherical, and the surface of the second lens 22 facing the illumination surface is a standard spherical.

[0050] The third lens 23 is a positive focal spherical lens. The surface of the third lens 23 facing the light source is convex, and the surface facing the illumination surface is concave. The radius of the surface of the third lens 23 facing the light source is smaller than the radius of the surface facing the illumination surface.

[0051] In one embodiment of this application, the first compound eye lens 111, the second compound eye lens 121, the first lens 21, the second lens 22, and the third lens 23 are made of fused silica. Fused silica has excellent optical properties. Quartz glass has good light transmittance across the entire spectrum from ultraviolet to infrared, and its visible light transmittance is over 92%. When used as a lens material, it has excellent optical performance.

[0052] In one embodiment of this application, the first compound eye lens 111 and the second compound eye lens 121 have the same focal length. With the same focal length, the two rows of compound eye lenses can form a symmetrical structure, which ensures that the principal rays emitted from the second row of compound eye lenses are parallel to the optical axis. When the light rays are incident at a non-0-degree angle of incidence, they can still coincide on the focal plane of the integrating lens group, thereby improving the uniformity of light intensity in the illumination center area.

[0053] In one embodiment of this application, the focal point of the first compound eye lens 111 coincides with the optical center of the second compound eye lens 121, so as to improve the overlap of each small light spot after the second compound eye lens is divided, reduce the size of the edge transition area with uneven light intensity, and further improve the light intensity uniformity of the illumination center area.

[0054] In one embodiment of this application, the focal lengths of the first compound eye lens 111, the second compound eye lens 121, the first lens 21, the second lens 22, and the third lens 23 are respectively: f (Fly-Eye)1=25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

[0055] In one embodiment of this application, the first compound eye lens 111 and the second compound eye lens 121 are square with a size of 0.4mm × 0.4mm.

[0056] In one embodiment of this application, the first compound eye lens array 11 and the second compound eye lens array 12 are arranged in a 51×51 array form, that is, the first compound eye lens array 11 and the second compound eye lens array 12 are composed of 2601 first compound eye lenses 111 and 2601 second compound eye lenses 121.

[0057] In one embodiment of this application, the microlens size of the first compound eye lens array 1111 and the second compound eye lens array 1221 of the present invention, namely the first compound eye lens 111 and the second compound eye lens 121, is 0.4mm × 0.4mm. The arrangement is preferably an odd-numbered symmetrical arrangement of 51 rows × 51 columns. This arrangement can ensure that when the incident angle of the parallel light source changes within the range of ±0.4°, the uniformity and position of the light field intensity of the 0.12mm × 0.12mm illumination surface do not change significantly, wherein the light field displacement of the uniform light intensity of the illumination surface is less than 1µm.

[0058] In one embodiment of this application, the thicknesses of the first compound eye lens 111, the second compound eye lens 121, the first lens 21, the second lens 22, and the third lens 23 are 1mm to 3mm, 1mm to 3mm, 4mm to 5mm, and 2mm to 3mm, respectively.

[0059] In one embodiment of this application, there is a first air gap between the first compound eye lens array 11 and the second compound eye lens array 12, a second air gap between the second compound eye lens array 12 and the first lens 21, a third air gap between the first lens 21 and the second lens 22, a fourth air gap between the second lens 22 and the third lens 23, and a fifth air gap between the third lens 23 and the illumination surface.

[0060] In one embodiment of this application, the thicknesses of the first air gap, the second air gap, the third air gap, the fourth air gap, and the fifth air gap are d1 = 27-29 mm, d2 = 2-4 mm, d3 = 2-4 mm, d4 = 0-1 mm, and d5 = 4-5 mm, respectively.

[0061] In one embodiment of this application, the first lens 21 and the second lens 22 are aspherical glass lenses, and the rotation curve of the surface shape of the aspherical lens satisfies the following equation:

[0062]

[0063] Where c is the curvature of the aspherical lens surface, k is the coefficient of the quadratic curve of the aspherical lens surface, and a1 to a8 are the values ​​of the aspherical polynomial.

[0064] The expression for c is r is the radius of the surface.

[0065] For example, the aspherical coefficients of the first lens 21 and the second lens 22 are shown in the table below:

[0066] k <![CDATA[a2]]> <![CDATA[a3]]> <![CDATA[a4]]> <![CDATA[a5]]> First lens 21 0 -3.411E-008 4.194E-007 8.062E-010 -2.261E-011 Second lens 22 0 -2.638E-004 6.501E-006 -2.223E-007 1.003E-009

[0067] The use of a glass aspherical lens structure can effectively improve the parallelism of the outgoing light from the integrating lens group 2 in the same field of view, thereby improving the uniformity of the light field intensity of the illumination surface. The light intensity non-uniformity is less than 0.2% within a light field range of 0.12mm×0.12mm, achieving high uniformity of the light field intensity of the illumination surface.

[0068] Please see Figure 4 , Figure 4 In one embodiment, a typical optical path system of a spatial light intensity homogenization system is given. Parallel light is emitted from the light source, enters the light intensity homogenization system, and passes sequentially through the first compound eye lens array 11, the second compound eye lens array 12, the first lens 21, the second lens 22, and the third lens 23 before being emitted and converged onto the illumination surface. This light intensity homogenization system can compensate for the minute non-uniformities within each narrow beam range after passing through the microscope group 1 multiple times, thereby achieving effective homogenization of the light and thus obtaining the required uniform energy on the illumination surface.

[0069] Please see Figure 5 , Figure 5 This is a schematic diagram of the uniformity of the illumination surface light field of a spatial light intensity homogenization system provided in one embodiment of this application. The relationship between the transition zone, the central zone and the light intensity can be seen from the figure.

[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0071] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A light intensity homogenization system, characterized in that: The light intensity homogenization system includes a micromirror group and an integrating mirror group arranged along the incident light path. The micro-mirror group includes a first compound eye lens array and a second compound eye lens array; The first compound eye lens array is composed of a plurality of first compound eye lenses. The surface of the first compound eye lens facing the light source is convex, and the surface facing the illumination surface is flat. The radius of curvature of the convex surface of the first compound eye lens is 12-14 mm. The second compound eye lens array is composed of a plurality of second compound eye lenses. The surface of the second compound eye lens facing the light source is a plane, and the surface facing the illumination surface is a convex surface. The radius of curvature of the convex surface of the second compound eye lens is the same as the radius of curvature of the convex surface of the first compound eye lens. The integrating lens group includes a first lens, a second lens, and a third lens; The first lens is a positive focal aspherical lens, both surfaces of the first lens are convex, the surface of the first lens facing the light source is an even-order aspherical surface, and the surface of the first lens facing the illumination surface is a standard spherical surface. The second lens is a positive focal aspherical lens. The surface of the second lens facing the light source is convex, and the surface facing the illumination surface is concave. The surface of the second lens facing the light source is an even-order aspherical, and the surface of the second lens facing the illumination surface is a standard spherical. The third lens is a positive focal spherical lens. The surface of the third lens facing the light source is convex, and the surface facing the illumination surface is concave. The radius of the surface of the third lens facing the light source is smaller than the radius of the surface facing the illumination surface.

2. The light intensity homogenization system according to claim 1, characterized in that: The first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are made of fused silica.

3. The light intensity homogenization system according to claim 1, characterized in that: The first compound eye lens and the second compound eye lens have the same focal length.

4. The light intensity homogenization system according to claim 3, characterized in that: The focal point of the first compound eye lens coincides with the optical center of the second compound eye lens.

5. The light intensity homogenization system according to claim 1, characterized in that: The focal lengths of the first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are respectively: f (Fly-Eye)1 =25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

6. The light intensity homogenization system according to claim 1, characterized in that: The first and second compound eye lens arrays are arranged in a 51×51 array configuration.

7. The light intensity homogenization system according to claim 6, characterized in that: The first and second compound eye lenses are square, with dimensions of 0.4mm × 0.4mm.

8. The light intensity homogenization system according to claim 1, characterized in that: The thicknesses of the first compound eye lens, the second compound eye lens, the first lens, the second lens, and the third lens are 1mm to 3mm, 1mm to 3mm, 4mm to 5mm, and 2mm to 3mm, respectively.

9. The light intensity homogenization system according to claim 1, characterized in that: There is a first air gap between the first compound eye lens array and the second compound eye lens array, a second air gap between the second compound eye lens array and the first lens, a third air gap between the first lens and the second lens, a fourth air gap between the second lens and the third lens, and a fifth air gap between the third lens and the illumination surface.

10. The light intensity homogenization system according to claim 9, characterized in that: The thicknesses of the first air gap, the second air gap, the third air gap, the fourth air gap, and the fifth air gap are d1 = 27-29 mm, d2 = 2-4 mm, d3 = 2-4 mm, d4 = 0-1 mm, and d5 = 4-5 mm, respectively.

11. The light intensity homogenization system according to claim 1, characterized in that: The first lens and the second lens are aspherical glass lenses, and the rotation curve of the surface shape of the aspherical lens satisfies the following equation: Where c is the curvature of the aspherical lens surface, k is the coefficient of the quadratic curve of the aspherical lens surface, and a1 to a8 are the values ​​of the aspherical polynomial.

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