Hybrid light mixing and condensing optical system for dental illumination

Abstract

The application discloses a mixed light converging optical system for dental illumination, which comprises a reflector, a structural support and an ommatidium lens; the reflector is fixed at the bottom of the structural support, a plurality of LED light sources are arranged in the middle of the structural support, the light emitting direction of the light sources is towards the reflector, and the ommatidium lens group is arranged at the upper part of the structural support; the ommatidium lens group is composed of an upper microstructure array and a lower microstructure array, the microstructure array is spherical, the upper microstructure array and the lower microstructure array are one-to-one corresponding in position and completely same in horizontal plane projection position; the curvature radius of the upper microstructure array and the lower microstructure array is completely same, the lower microstructure array is inscribed in a straight line contour line, the upper microstructure array is inscribed in a convex outer contour line, and the convex outer contour line is a spherical curve.

Description

Technical Field

[0001] This invention belongs to the field of LED light distribution lenses, and specifically relates to a light mixing and converging optical system for dental lighting. Background Technology

[0002] Currently, with the improvement of living standards, the dental medical service market is growing rapidly, and the demand for dental lighting fixtures is also increasing. LEDs, with their small light-emitting surface and concentrated light energy, have become the main light source. However, dental lighting needs to form a rectangular light spot that just covers the entire oral cavity within about the length of the dentist's arm (a specified distance of 730mm), typically only 100mm*200mm in size. A high color rendering index (CRI) is also desired; currently, dental lighting ideally needs a CRI of 97 or higher. However, ultra-high CRIs cannot be achieved through single-chip packaging; they can only be achieved through multi-chip packaging (COB) or by arranging discrete LEDs with different color temperatures. Regardless of the solution, the convergence angle is less than 5 degrees. Existing color mixing technologies that form such a small light spot typically have an optical aperture greater than 100mm and cannot achieve uniform color mixing; or they are extremely inefficient, making them difficult to meet the needs of dental lighting applications. Summary of the Invention

[0003] In view of the problems in related technologies, the present invention designs a light-gathering optical system for dental lighting to overcome the problems of the prior art described in the background section.

[0004] The proposed solution is as follows: a light-gathering optical system for dental lighting, comprising a reflector and a structural support. The reflector is mounted at the bottom of the structural support, and an LED light source is mounted in the middle of the structural support, above the reflector, with the light emission direction facing the reflector. A compound eye lens group is mounted on the upper part of the structural support.

[0005] The compound eye lens group includes one or two lenses. The surface of the lens is provided with an upper microstructure unit array and a lower microstructure unit array. The positions of the microstructure units in the upper microstructure unit array and the lower microstructure unit array correspond one-to-one in the vertical direction, and the two are at the same position when projected on the horizontal plane.

[0006] The microstructure unit is a spherical surface protruding from the lens surface, and the upper microstructure unit and the corresponding lower microstructure unit have the same radius of curvature.

[0007] The lower microstructure units are all internally tangent to a straight profile line, and the upper microstructure units are all internally tangent to an outwardly convex profile line, which is a spherical curve.

[0008] Preferably, the upper microstructure unit array and the lower microstructure unit array are formed on the upper and lower surfaces of a lens, respectively, and the lens is an integral lens; the radius of curvature R of the convex contour line is R = H*(n-1), where n is the refractive index of the lens and H is the distance from the vertex of the convex contour line to the converging focal point.

[0009] Preferably, the relationship between the spherical radius wr of the microstructure unit, the refractive index n of the lens, and the center thickness hm and edge thickness hs of the lens satisfies:

[0010] (hs-0.2)*(n-1) / n <wr<(hm+0.2)*(n-1) / n。

[0011] Preferably, the upper and lower microstructure unit arrays are replaced by being formed on the surfaces of two lenses, which are the upper lens and the lower lens, respectively; the relationship between the center thickness h1m of the upper lens, the edge thickness h2 of the lower lens, the distance between the two lenses hh, the refractive index n of each lens, and the center thickness hm of the integral lens satisfies: h1m + h2 + n * hh = hm.

[0012] Preferably, the upper microstructure unit array and the lower microstructure unit array are formed on the surfaces of two lenses, which are the upper lens and the lower lens, respectively.

[0013] The relationship between the spherical radius wr of the microstructure, the refractive index n of the two lenses, the center thickness h1m of the upper lens, the edge thickness h1s of the upper lens, the edge thickness h2 of the lower lens, and the thickness hh of the air layer between the two lenses satisfies:

[0014] (h1s+h2+n*hh-0.2)*(n-1) / n <wr<(h1m+h2+n*hh+0.2)*(n-1) / n。

[0015] Preferably, the diameter D of the compound eye lens group and the distance H from the vertex of the convex contour line of the compound eye lens to the converging focal point satisfy: D < 0.1 * H.

[0016] Preferably, the microstructure units of the compound eye lens group are arranged in a rectangular array or a hexagonal array.

[0017] Preferably, the reflector is a rotationally symmetric curved surface with a parabolic cross-section; a reflective film is coated on the concave direction of the curved surface.

[0018] Preferably, the structural support member has a long strip-shaped structure in the middle, and the LED light source is installed at the bottom of the long strip-shaped structure with the light-emitting surface facing the reflector.

[0019] Preferably, the structural support component is black.

[0020] Preferably, a split lens group consisting of two lenses, an upper lens and a lower lens, is provided with the microstructure unit on the upper surface of the upper lens and the lower surface of the lower lens.

[0021] Preferably, a split lens group consisting of two lenses, an upper lens and a lower lens, is provided with the microstructure unit on the upper surface of the upper lens and the upper surface of the lower lens.

[0022] Preferably, a split lens group consisting of upper and lower lenses is provided with the microstructure unit on the lower surface of the upper lens and the lower surface of the lower lens.

[0023] Preferably, a split lens group consisting of two lenses, an upper lens and a lower lens, is provided with the microstructure unit on the lower surface of the upper lens and the upper surface of the lower lens.

[0024] The beneficial effect of this invention is that it solves the problem of achieving high color rendering index lighting and light convergence effect in dental lighting fixtures within an effective space. Attached Figure Description

[0025] Figure 1 This is a diagram illustrating the optical principle of the compound eye technology of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the optical path in Embodiment 1 of the present invention;

[0028] Figure 4 This is a schematic diagram of the microstructure array in Embodiment 1 of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0030] Figure 6 This is a schematic diagram of the microstructure optical principle of Embodiment 2 of the present invention;

[0031] Figure 7 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0033] Figure 9 This is a schematic diagram of the structure of Embodiment 5 of the present invention;

[0034] Figure 10 This is a schematic diagram showing that the microstructure array is arranged in a hexagonal matrix in an embodiment of the present invention;

[0035] Figure 11 This is a schematic diagram of the structural support component in an embodiment of the present invention;

[0036] Figure 12 This is a light spot diagram of the present invention;

[0037] Figure 13 This is a true-color CCT color difference distribution diagram of the present invention (converted to grayscale display); Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In convergent lighting applications, it is typically necessary to achieve uniform light mixing. Common methods used in the mixing process significantly increase the beam angle, and achieving uniform color mixing while minimizing the beam angle remains a common challenge across the industry.

[0040] Among the many solutions, using compound eye technology (i.e., the technique of setting up an array of microstructured units on the lens surface) to achieve color mixing is an important technical means. For example... Figure 1 The diagram illustrates the optical principle of the compound eye technology of this invention. Typically, a compound eye (i.e., an array of microstructured units) is loaded onto a planar optical sheet. Both the upper and lower layers are loaded with the same array of microstructured units, with each microstructured unit in the two layers corresponding one-to-one. The first layer of microstructured units images and converges the light rays gathered by the reflector cup onto the second layer of microstructured units, while the second layer images the first layer of microstructured units to infinity. This allows for the uniform mixing of different colors of light without significantly altering the original beam angle. However, if it is necessary to converge light to a single focal point, the above structure cannot be used. Therefore, the technical solution of this invention mainly addresses the problem of realizing such a converged light path to a specific focal point.

[0041] Example 1, as Figure 2 , 3 As shown in 4, 10, and 11:

[0042] In this embodiment, a light-gathering optical system for dental lighting includes a reflector and a structural support. The reflector is mounted on the bottom of the structural support, and an LED light source is mounted in the middle of the structural support, above the reflector, with the light emission direction facing the reflector. A compound eye lens group is mounted on the upper part of the structural support.

[0043] The compound eye lens group includes a lens. The upper microstructure unit array and the lower microstructure unit array are respectively formed on the upper and lower surfaces of the lens. The lens is an integral lens. The positions of the microstructure units of the upper microstructure unit array and the lower microstructure unit array correspond one-to-one in the vertical direction, and their projection positions on the horizontal plane (xy plane) are the same.

[0044] The microstructure unit is a spherical surface protruding from the lens surface, and the upper microstructure unit and the corresponding lower microstructure unit have the same radius of curvature; the lower microstructure unit is inscribed in a straight line contour, and the upper microstructure unit is inscribed in a convex contour, which is a spherical curve.

[0045] The structure of this embodiment 1 and Figure 1 The main difference is that the compound eye lens group in this embodiment includes a lens whose light-incident surface 21 and light-exit surface 22 are loaded with periodic microstructure units 23. The microstructure units are spherical protrusions, and the microstructure units loaded on the light-incident surface 21 and the light-exit surface 22 correspond one-to-one, that is, the protrusion height dh and the spherical diameter wr of the microstructure units are exactly the same, and the arrangement interval of the upper and lower microstructure units is also exactly the same.

[0046] The light-exiting surface 22 of the lens is inscribed in a contour line 24, which is a sphere with a radius of curvature R. The microstructure of the light-incident surface 21 is inscribed in a straight contour line 25. Let the distance between the converging focal point and the vertex of the upper surface contour line 24 of the lens be H, and the refractive index of the lens be n. Then the radius of curvature R of the sphere satisfies the following relationship: R = H * (n - 1).

[0047] like Figure 3 A careful analysis of the compound eye's principle reveals that its light-mixing mechanism can be summarized as follows: It consists of an array of two opposing spherical surfaces, corresponding to the incident surface AB and the exit surface CD, respectively. Parallel light incident from AB at an angle α to the optical axis converges at points C and D, and after refraction on the exit surface CD, the light rays are distributed within a beam angle range of -α to α. Conversely, parallel light incident from AB converges through surface AB to the midpoint of CD, and after refraction on the exit surface CD, forms a beam angle distribution of -α to α. Through this light mixing, light rays of different colors originating from different directions can be mixed and emitted within a beam angle range of -α to α.

[0048] For a compound eye lens composed of multiple similar structures, if the length L of its microstructure unit is too small and the edge ray angle θ is greater than the controllable range α, then incident rays greater than α will scatter to adjacent exiting surfaces, forming stray light. If the length of the compound eye microstructure unit is too large and the edge ray angle θ is less than the controllable range α, some areas of the compound eye microstructure unit will not emit light, which will cause a reduction in the central light intensity.

[0049] For the case where the external contours of the microstructure units are all straight lines, the relationship between the spherical radius r0 of the microstructure unit, the refractive index n of the lens, and the center thickness h0 of the upper and lower contours of the lens satisfies:

[0050] r0=h0*(n-1) / n.

[0051] However, in this embodiment, the lens has a diameter of D, and the lens thickness varies from the edge to the center. The thickness at the center of the integral lens is hm, and the thickness at the edge is hs. Therefore, the optimal spherical radius wr of the microstructure unit needs to satisfy:

[0052] hs*(n-1) / n <wr<hm*(n-1) / n;

[0053] Considering the effects of fabrication redundancy and the height dh of the microstructure surface, the range of the spherical radius of the optimal microstructure element after correction is:

[0054] (hs-0.2)*(n-1) / n <wr<(hm+0.2)*(n-1) / n;

[0055] Since the diameter D is much smaller than the distance H from the lens to the converging surface, in this embodiment, D < 0.1H.

[0056] In this embodiment, as Figure 4 As shown, the microstructure array is a rectangular array, with each microstructure unit having a length:width ratio of approximately 2:1. (In other embodiments, the microstructure array can also be as follows...) Figure 10 The hexagonal matrix arrangement shown.

[0057] Additionally, a long strip-shaped structure is provided in the middle of the structural support member, and the LED light source is installed at the bottom of the long strip-shaped structure with the emitting surface facing the reflector. For example... Figure 11 As shown.

[0058] It includes a reflector 111, a structural support 112, and a compound eye lens group 113; the reflector 111 is fixedly mounted on the bottom of the structural support 112, and the reflector is a rotationally symmetric curved surface with a parabolic cross-section; the concave direction 1111 of the curved surface is coated with a reflective film. The reflector is connected to the structural support 112 through several U-shaped protrusions 1112 protruding from its edge.

[0059] The structural support component 112 is cylindrical, with a columnar mounting position 1121 at the bottom for connection with the reflector 111, and a long strip-shaped mounting rod 1122 for mounting LED light sources in the middle. The mounting rod 1122 extends through both sides of the cylindrical component 112, and the LED light source is located at the center of the cylinder, consisting of several LEDs of different colors, with the light emission direction facing the reflector 111.

[0060] A compound eye lens assembly 113 is mounted on the upper end of the structural support 112. The curved surface of the lowest point 1131 of the compound eye lens assembly is placed above the upper surface of the mounting rod 1122, similar to the reflector 111, with several U-shaped protrusions 1132 protruding from the edge. The protrusions 1132 of the compound eye lens assembly correspond one-to-one with the protrusions 1112 of the reflector. To reduce stray light, the structural support 112 is painted black.

[0061] Figure 12 The image shown is a spot diagram of this embodiment. It can be seen that the present invention can achieve a very clean rectangular spot with clear cutoff and no stray light outside the spot.

[0062] Figure 13 The image is a true-color CCT color difference distribution diagram (converted to grayscale due to the requirements of the attached image). It uses three LED light sources of different colors arranged in parallel, with uniform light color distribution and very small color difference of light spots throughout the entire color mixing range.

[0063] Example 2, as Figure 5 , 6 As shown:

[0064] An improvement upon Embodiment 1, differing from Embodiment 1 in that the compound eye lens group formed in this embodiment consists of two lenses 51 and 52. The upper surface 511 of lens 51 and the lower surface 522 of lens 52 are microstructure unit array surfaces. The lower surface 512 of lens 51 is planar, and the microstructure on the upper surface of lens 51 is inscribed within an arc-shaped contour surface 513 (convex contour line). This contour surface is spherical, and the relationship between the radius R of the sphere and the distance H from the converging focal point to the vertex of the sphere is as follows:

[0065] R = H*(n-1);

[0066] The upper surface 521 of lens 52 is planar, and the microstructure units on the lower surface are also inscribed in a plane 523 (a straight outline). Compared with Embodiment 1, this is equivalent to cutting the lens of Embodiment 1 into two pieces, but a certain air layer needs to be retained in the middle. In this embodiment, the center thickness of lens 51 is h1m, the edge thickness is h1s, and the thickness of the air layer is hh; the thickness of lens 52 is h2.

[0067] like Figure 6 As shown, the spherical surface of the first central microstructure unit converges to the center of the upper surface 511 of the lens 51. Assuming the incident light is a collimated ray, it can be seen from the geometric relationship that:

[0068] L / 2=(h1m+h2)*tanβ+hh*tanα

[0069] Compared with the center thickness hm of Example 1, the following relationship exists:

[0070] L / 2=hm*tanβ

[0071] Therefore, for the same D and H, when α is very small, the following relationship holds:

[0072] hm=h1m+h2+n*hh

[0073] Accordingly, in this embodiment, the lens has a diameter of D, and the lens thickness varies from the edge to the center. The optimal spherical radius wr satisfies:

[0074] (h1s+h2+n*hh)*(n-1) / n <wr<(h1m+h2+n*hh)*(n-1) / n;

[0075] Considering the effects of fabrication redundancy and the height dh of the microstructure surface, the range of the corrected optimal microstructure spherical radius is:

[0076] (h1s+h2+n*hh-0.2)*(n-1) / n <wr<(h1m+h2+n*hh+0.2)*(n-1) / n。

[0077] Example 3, as Figure 7 As shown:

[0078] This embodiment is an improvement on embodiment 2. The difference between it and embodiment 2 is that, for example... Figure 7 As shown: the microstructure unit of the lower lens 72 is disposed on the upper surface 721 of the lower lens, while the lower surface 722 of the lower lens is a plane. Everything else is the same as in Embodiment 2.

[0079] Example 4, as Figure 8 As shown:

[0080] This embodiment is an improvement on embodiment 2. The difference between it and embodiment 2 is that, for example... Figure 8 As shown: the microstructure unit array of the upper lens 81 is disposed on the lower surface 812 of the upper lens. The upper surface 811 of the upper lens is a smooth spherical surface, which is equivalent to the convex contour surface (convex contour line) inscribed by the upper microstructure unit. The upper surface 821 of the lower lens is a plane, and the lower surface 822 is provided with the microstructure unit array. The rest is the same as in Embodiment 2.

[0081] Example 5, as Figure 9 As shown:

[0082] This embodiment is an improvement on embodiment 2. The difference between it and embodiment 2 is that, for example... Figure 9As shown: the microstructure unit array of the upper lens 91 is disposed on the lower surface 912 of the upper lens, and the upper surface 911 of the upper lens is a smooth spherical surface, which is equivalent to the convex contour surface (convex contour line) inscribed by the upper microstructure unit; the upper surface 921 of the lower lens 92 is a plane, and the upper surface 922 is a microstructure unit array, and the rest is the same as in embodiment 2.

[0083] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the invention.

Claims

1. A light-converging optical system for dental lighting, comprising a reflector and a structural support, wherein the reflector is mounted at the bottom of the structural support, and an LED light source is mounted at the middle of the structural support, above the reflector, with the light emission direction of the light source facing the reflector; characterized in that, The upper part of the structural support component is equipped with a compound eye lens group; The compound eye lens group includes one or two lenses. The surface of the lens is provided with an upper microstructure unit array and a lower microstructure unit array. The positions of the microstructure units in the upper microstructure unit array and the lower microstructure unit array correspond one-to-one in the vertical direction, and the two are at the same position when projected on the horizontal plane. The microstructure unit is a spherical surface protruding from the lens surface, and the upper microstructure unit and the corresponding lower microstructure unit have the same radius of curvature. The lower microstructure units are all internally tangent to a straight profile line, and the upper microstructure units are all internally tangent to an outwardly convex profile line, which is a spherical curve.

2. The light-mixing and converging optical system according to claim 1, characterized in that, When the compound eye lens group includes a single lens, the upper microstructure unit array and the lower microstructure unit array are respectively formed on the upper and lower surfaces of the single lens, and the lens is an integral lens; the radius of curvature R of the convex contour line is R = H*(n-1), where n is the refractive index of the lens and H is the distance from the vertex of the convex contour line to the converging focal point.

3. The light-mixing and converging optical system according to claim 2, characterized in that, The relationship between the spherical radius wr of the microstructure unit, the refractive index n of the lens, and the center thickness hm and edge thickness hs of the lens satisfies: (hs-0.2)*(n-1) / n <wr<(hm+0.2)*(n-1) / n。 4. The light-mixing and converging optical system according to claim 1, characterized in that, When the compound eye lens group includes two lenses, the upper microstructure unit array and the lower microstructure unit array are respectively formed on the surfaces of the two lenses, which are the upper lens and the lower lens, respectively; the upper microstructure unit array is located on the upper or lower surface of the upper lens, and the lower microstructure unit array is located on the upper or lower surface of the lower lens. An air layer is present between the two lenses, and the two lenses and the air layer are combined to form a single lens. When the incident light is collimated and converges to the center of the upper surface of the upper lens, the relationships between the center thickness h1m of the upper lens, the edge thickness h2 of the lower lens, the distance between the two lenses hh, the refractive index n of each lens, and the center thickness hm of the single lens satisfy the following: h1m+h2+n*hh=hm.

5. The light-mixing and converging optical system according to claim 1, characterized in that, When the compound eye lens group includes two lenses, the upper microstructure unit array and the lower microstructure unit array are respectively formed on the surfaces of the two lenses, which are the upper lens and the lower lens, respectively; the upper microstructure unit array is located on the upper or lower surface of the upper lens, and the lower microstructure unit array is located on the upper or lower surface of the lower lens. The relationship between the spherical radius wr of the microstructure, the refractive index n of the two lenses, the center thickness h1m of the upper lens, the edge thickness h1s of the upper lens, the edge thickness h2 of the lower lens, and the thickness hh of the air layer between the two lenses satisfies: (h1s+h2+n*hh-0.2)*(n-1) / n <wr<(h1m+h2+n*hh+0.2)*(n-1) / n。 6. The light-mixing and converging optical system according to claim 1, characterized in that, The diameter D of the compound eye lens group and the distance H from the vertex of the convex contour line of the compound eye lens to the converging focal point satisfy: D < 0.1 * H.

7. The light-mixing and converging optical system according to claim 1, characterized in that, The microstructure units of the compound eye lens group are arranged in a rectangular array or a hexagonal array.

8. The light-mixing and converging optical system according to claim 1, characterized in that, The reflector is a rotationally symmetric curved surface with a parabolic cross-section; a reflective film is coated on the concave side of the curved surface.

9. The light-mixing and converging optical system according to claim 1, characterized in that, The structural support component has a long strip-shaped structure in the middle, and the LED light source is installed at the bottom of the long strip-shaped structure with the light-emitting surface facing the reflector.

10. The light-mixing and converging optical system according to claim 1, characterized in that, The structural support component is black.

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