Collimating lens, design method thereof and collimating system

Abstract

The invention provides a collimating lens, a design method thereof and a collimating system, and relates to the technical field of optics. The embodiment of the invention provides a collimating lens which comprises a transmission part and / or a reflection part, and the reflection part is located on the periphery of the transmission part. The transmission part and the reflection part form an accommodating cavity for accommodating a light source, the transmission part comprises a first surface and a second surface, the first surface is opposite to the second surface, and the second surface is positioned between the first surface and the accommodating cavity; the reflection part comprises a fifth surface, and the fifth surface is connected with the first surface. According to the collimating lens provided by the embodiment of the invention, the transmission part shapes small-angle light beams emitted by the light source into parallel light beams, and the reflection part shapes large-angle light beams emitted by the light source into parallel light beams, so that the light beams emitted by the light source are collimated; and the intensity distribution of the light spots emitted by the collimating lens on the plane vertical to the propagation direction is uniform.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a collimating lens and a design method thereof, and a collimating system. Background Art

[0002] Existing total internal reflection collimating lenses divide the light output from a light source into two parts: a transmissive portion and a reflective portion. The transmissive portion collimates small-angle light, while the reflective portion uses the principle of total internal reflection to collimate large-angle light. Because LED light output is typically Lambertian, the light intensity distribution is uneven at all angles. Existing total internal reflection collimating lenses simply collimate the light at all angles, resulting in an uneven light spot on the target surface. Summary of the Invention

[0003] The embodiment of the present invention provides a collimating lens and a design method thereof, and a collimating system. The collimating lens can collimate a light beam emitted by a point light source and make the intensity distribution of the light spot emitted by the collimating lens uniform on a plane perpendicular to the propagation direction.

[0004] An embodiment of the present invention provides a collimating lens, comprising a transmissive portion and / or a reflective portion, wherein the reflective portion is located at the periphery of the transmissive portion;

[0005] The transmissive portion and the reflective portion form a receiving cavity for receiving the light source, the transmissive portion includes a first surface and a second surface, the first surface is opposite to the second surface, and the second surface is located between the first surface and the receiving cavity;

[0006] The reflecting portion includes a fifth surface connected to the first surface.

[0007] Optionally, the first surface and the second surface are free-form surfaces; the first surface bulges in a direction away from the accommodating cavity, and the second surface bulges toward the accommodating cavity.

[0008] Optionally, the curvature of the first surface is greater than the curvature of the second surface.

[0009] Optionally, the fifth surface is a free-form surface;

[0010] The fifth surface protrudes toward the accommodating cavity.

[0011] Optionally, the first surface forms a first Fresnel lens, and / or the fifth surface forms a second Fresnel lens.

[0012] Optionally, the reflective portion further includes a third surface and a fourth surface, and the third surface is connected to the second surface;

[0013] The light incident on the reflective portion through the third surface is totally reflected by the fourth surface and then emitted from the reflective portion through the fifth surface.

[0014] Optionally, the third surface is a conical surface or a spherical surface.

[0015] Optionally, the transmissive part and the reflective part are made of transparent optical plastic.

[0016] In a second aspect, an embodiment of the present invention provides a collimating system, comprising: a light source and a collimating lens provided by any embodiment of the present invention, wherein the light source is disposed in a receiving cavity of the collimating lens.

[0017] In a third aspect, an embodiment of the present invention provides a method for designing a collimating lens, comprising:

[0018] According to the position of the point light source and the positional relationship between the incident light and the outgoing light, a coordinate equation group of the first surface and the second surface is obtained;

[0019] Obtaining coordinates of the first surface and the second surface according to the coordinate equation group, the starting point of the first surface and the starting point of the second surface;

[0020] The end point of the first surface is used as the starting point of the fifth surface, and the coordinates of the fifth surface are obtained according to the coordinate equation group of the first surface and the fifth surface, and the starting point of the fifth surface.

[0021] The collimating lens provided in an embodiment of the present invention has a transmission part that shapes a small-angle light beam emitted by a light source into a parallel light beam, and a reflection part that shapes a large-angle light beam emitted by the light source into a parallel light beam, thereby collimating the light beam emitted by the light source and making the intensity distribution of the light spot emitted by the collimating lens uniform on the plane perpendicular to the propagation direction.

[0022] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution in this embodiment, the following briefly introduces the drawings required for use in the description of the embodiment. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 is a side view of a collimating lens provided by an embodiment of the present invention;

[0025] Figure 2 is a side view of another collimating lens provided by an embodiment of the present invention;

[0026] Figure 3 1 is a schematic diagram of the optical path of another collimating lens provided by an embodiment of the present invention;

[0027] Figure 4is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention;

[0028] Figure 5 is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention;

[0029] Figure 6 is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention;

[0030] Figure 7 1 is a schematic structural diagram of another collimating lens provided by an embodiment of the present invention;

[0031] Figure 8 is a top view of another collimating lens provided by an embodiment of the present invention;

[0032] Figure 9 is a bottom view of another collimating lens provided by an embodiment of the present invention;

[0033] Figure 10 1 is a schematic structural diagram of another collimating lens provided by an embodiment of the present invention;

[0034] Figure 11 1 is a schematic structural diagram of another collimating lens provided by an embodiment of the present invention;

[0035] Figure 12 is a flow chart of a design method provided by an embodiment of the present invention;

[0036] Figure 13 is a coordinate diagram of a point light source, incident light, and outgoing light provided by an embodiment of the present invention;

[0037] Figure 14 is a coordinate diagram of each surface of the collimating lens provided by an embodiment of the present invention;

[0038] Figure 15 is a coordinate diagram of each surface of another collimating lens provided by an embodiment of the present invention;

[0039] Figure 16 It is a structural diagram of the first surface, the second surface, the third surface, the fourth surface and the fifth surface calculated based on the coordinate equation group. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] An embodiment of the present invention provides a collimating lens, Figure 1 is a side view of a collimating lens provided by an embodiment of the present invention, with reference to Figure 1 The collimating lens includes a transmissive portion 100 and / or a reflective portion 200, and the reflective portion 200 is located at the periphery of the transmissive portion 100; the transmissive portion 100 and the reflective portion 200 form a receiving cavity 400 for accommodating the light source 300, and the transmissive portion 100 includes a first surface 101 and a second surface 102, the first surface 101 is opposite to the second surface 102, and the second surface 102 is located between the first surface 101 and the receiving cavity 400; the reflective portion 200 includes a fifth surface 105, and the fifth surface 105 is connected to the first surface 101.

[0043] refer to Figure 1 , the first surface 101 and the fifth surface 105 are different surfaces of the collimating lens, and the fifth surface 105 is located on the periphery of the first surface 101 and is connected to the first surface 101. The light source 300 is located in the accommodating cavity 400, and the axis 500 is the rotational symmetry axis of the collimating lens. Among the light beams emitted by the light source 300, the light beam whose propagation direction forms a smaller angle with the axis 500 will be incident from the second surface 102 and emitted from the first surface 101. This part of the light beam is a small-angle light beam, and the small-angle light beam will pass through the transmitting part 100, while the light beam whose propagation direction forms a larger angle with the axis 500 will be emitted from the fifth surface 105. This part of the light beam is a large-angle light beam. The angle between the large-angle light beam and the axis 500 is larger than the angle between the small-angle light beam and the axis 500. After passing through the collimating lens, the light beam emitted by the light source 300 will become a parallel light beam.

[0044] The collimating lens provided in an embodiment of the present invention has a transmission part that shapes a small-angle light beam emitted by a light source into a parallel light beam, and a reflection part that shapes a large-angle light beam emitted by the light source into a parallel light beam, thereby collimating the light beam emitted by the light source and making the intensity distribution of the light spot emitted by the collimating lens uniform on the plane perpendicular to the propagation direction.

[0045] Optionally, refer to Figure 1 The first surface 101 and the second surface 102 are free-form surfaces; the first surface 101 convexly extends away from the accommodating cavity 400, while the second surface 102 convexly extends toward the accommodating cavity 400. The first surface 101 and the second surface 102 form a convex lens-like structure, which can converge the light beam emitted by the light source 300 into a parallel beam. Free-form surfaces offer greater design freedom, minimizing the aberration caused by the first and second surfaces 101 and 102.

[0046] Figure 2 is a side view of another collimating lens provided by an embodiment of the present invention, Figure 3 This is a schematic diagram of the optical path of another collimating lens provided by an embodiment of the present invention, referring to Figure 2 and Figure 3 The reflecting part 200 also includes a third surface 103 and a fourth surface 104, and the third surface 103 is connected to the second surface 102; the light incident into the reflecting part 200 through the third surface 103 is totally reflected at the fourth surface 104 and then emitted from the fifth surface 105 to the outside of the reflecting part 200.

[0047] refer to Figure 2 and Figure 3 The small-angle light beam is incident on the collimating lens from the second surface 102, passes through the transmission portion 100, and is emitted from the first surface 101 to form a parallel light beam. The large-angle light beam is incident on the collimating lens from the third surface 103, is totally reflected at the fourth surface 104, and finally is emitted from the fifth surface 105 to form a parallel light beam. Optionally, the third surface 103 is a draft surface.

[0048] Optionally, the third surface 103 is a conical surface or a spherical surface. Figure 2 , Figure 2 Third surface 103 is a spherical surface. When a high-angle light beam emitted from light source 300 enters the collimating lens through third surface 103, the propagation direction of the high-angle light beam does not change. In other words, the high-angle light beam is incident normally or approximately normally on third surface 103. The collimating lens has a rotationally symmetrical structure. Third surface 103 is located outside second surface 102, and fifth surface 105 is located outside first surface 101.

[0049] Optionally, refer to Figure 1 , the curvature of the first surface 101 is greater than the curvature of the second surface 102 .

[0050] refer to Figure 2The fourth and fifth surfaces 104 and 105 are free-form surfaces; the fifth surface 105 is convex toward the accommodating cavity 400. The fifth surface 105 is generally arc-shaped and concave toward the fourth surface 104. The first and fifth surfaces 101 and 105 are the light-emitting surfaces of the collimating lens, i.e., the light-emitting surfaces. The second and third surfaces 102 and 103 are the light-incident surfaces of the collimating lens, i.e., the light-entering surfaces. The light beam emitted by the light source 300 enters the collimating lens through the second and third surfaces 102 and 103.

[0051] Figure 4 is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention, Figure 5 is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention, Figure 6 This is a partial schematic diagram of another collimating lens provided by an embodiment of the present invention, referring to Figure 4 、 Figure 5 and Figure 6 The first surface 101 forms a first Fresnel lens, and / or the fifth surface 105 forms a second Fresnel lens. Figure 4 The first surface 101 is a curved surface, and the fifth surface 105 forms a second Fresnel lens; Figure 5 The first surface 101 forms a first Fresnel lens, and the fifth surface 105 is a curved surface; Figure 6 The first surface 101 forms a first Fresnel lens, and the fifth surface 105 forms a second Fresnel lens. By modifying the first surface 101 into multiple sawtooth structures, the first Fresnel lens is formed. Similarly, by modifying the fifth surface 105 into multiple sawtooth structures, the fifth surface 105 is formed into a second Fresnel lens. The first Fresnel lens includes multiple first Fresnel zones arranged around its central axis, and the second Fresnel lens includes multiple second Fresnel zones arranged around its central axis. The first Fresnel zones and the second Fresnel zones are arranged in opposite directions, that is, the sawtooth structures of the first and second Fresnel zones face opposite directions. This structure not only focuses light but also makes the collimating lens thinner, reducing the volume and material consumption of the collimating lens.

[0052] Optionally, the transmissive portion 100 and the reflective portion 200 are made of transparent optical plastic, which has the characteristics of high transmittance, low dispersion, and strong impact resistance.

[0053] Figure 7 is a structural diagram of another collimating lens provided by an embodiment of the present invention. Figure 8 is a top view of another collimating lens provided by an embodiment of the present invention, Figure 9 This is a bottom view of another collimating lens provided by an embodiment of the present invention, with reference to Figure 2 、 Figure 7 、 Figure 8 and Figure 9 ,Will Figure 2 The center part of the lens is cut off so that the top view of the lens is hexagonal, and we can get Figure 7 、 Figure 8 and Figure 9 The collimating lens shown in the figure has a regular shape, which can realize the dense arrangement of multiple similar lenses, save space, and realize the output of parallel light beams in a large area. Figure 2 The collimating lens in is intercepted into other polygons, such as a quadrilateral or a triangle.

[0054] Figure 10 is a structural diagram of another collimating lens provided by an embodiment of the present invention. Figure 11 This is a schematic diagram of the structure of another collimating lens provided by an embodiment of the present invention, referring to Figure 2 、 Figure 10 and Figure 11 , Figure 10 The collimating lens only includes a first surface 101 and a second surface 102, wherein the first surface 101 and the second surface 102 are connected by a flat surface or a curved surface. Figure 11 The collimating lens only includes the fourth surface 104 and the fifth surface 105 , and the fourth surface 104 and the fifth surface 105 are connected by a flat surface or a curved surface.

[0055] Based on a unified inventive concept, embodiments of the present invention provide a collimation system, comprising: a light source and a collimating lens provided by any embodiment of the present invention, wherein the light source is disposed within a receiving cavity of the collimating lens. Because the collimation system includes the collimating lens provided by any embodiment of the present invention, the collimation system has the same or corresponding beneficial effects as the collimating lens.

[0056] Based on the unified inventive concept, an embodiment of the present invention provides a design method for a collimating lens. Figure 12 This is a flow chart of a design method provided by an embodiment of the present invention, refer to Figure 12 , the design methods include:

[0057] S101 , obtaining a coordinate equation group of the first surface and the second surface according to the position of the point light source and the positional relationship between the incident light and the outgoing light.

[0058] Figure 13 is a coordinate diagram of a point light source, incident light, and outgoing light provided by an embodiment of the present invention, with reference to Figure 13, light source 300 is located at the coordinate origin, OP0 is the optical axis of the collimating lens, which coincides with the OZ axis, the angle between the incident light OP1 and OP0 is θ1, the angle between the incident light OP2 and OP0 is θ2, the incident light OP1 corresponds to the outgoing light P1Q1, and the incident light OP2 corresponds to the outgoing light P2Q2. Based on the coordinates of the incident light OP1, incident light OP2, outgoing light P1Q1, and outgoing light P2Q2 and the law of refraction, the coordinate equations for the first and second surfaces and the starting points of the first and second surfaces can be calculated. For example, the starting point of the first surface is T0, and the normal at T0 is perpendicular to the OZ axis. The starting point of the second surface is P0, and the normal at P0 is perpendicular to the OZ axis.

[0059] S102 : Obtain coordinates of the first surface and the second surface according to the coordinate equation group, the starting point of the first surface, and the starting point of the second surface.

[0060] Figure 14 is a coordinate diagram of each surface of the collimating lens provided by an embodiment of the present invention, with reference to Figure 14 According to the coordinate equations of the first and second surfaces, the positional relationship between two adjacent points in the first and second surfaces can be obtained. Therefore, given the starting point T0 of the first surface and the starting point P0 of the second surface, all the coordinate points of the first and second surfaces can be iteratively calculated based on the coordinates of the starting points. The first and second surfaces can be obtained by connecting the above coordinate points respectively.

[0061] S103. Taking the end point of the first surface as the starting point of the fifth surface, and obtaining the coordinates of the fifth surface according to the coordinate equation group of the first surface and the fifth surface, and the starting point of the fifth surface.

[0062] Specifically, Figure 15 is a coordinate diagram of each surface of another collimating lens provided by an embodiment of the present invention, with reference to Figure 14 and Figure 15 According to the positional relationship between the incident light and the outgoing light, the coordinate equation group of the fifth surface 105 can be obtained. According to the coordinate equation group of the fifth surface 105, the positional relationship between two adjacent points on the fifth surface 105 can be obtained. Then, the end point of the first surface 101 is used as the starting point of the fifth surface 105, and then the coordinates of all points on the fifth surface 105 can be calculated.

[0063] Continue to refer Figure 14 and Figure 15 , the OZ axis is the rotation axis, and the first surface 101, the second surface 102 and the fifth surface 105 are rotated 360° around the OZ axis to obtain a collimating lens.

[0064] Similarly, the end point of the second surface 102 is used as the starting point of the third surface 103, and the coordinate equation group of the third surface 103 and the fourth surface 104 is obtained based on the light. The coordinates of all points on the third surface 103 and the fourth surface 104 can be obtained based on the coordinate equation group. Figure 14 The third surface 103 in is a curved surface, Figure 15 The third surface 103 is a plane. Figure 16 It is a structural diagram of the first surface, the second surface, the third surface, the fourth surface and the fifth surface calculated based on the coordinate equation group.

[0065] The above specific embodiments do not limit the scope of this invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention shall be included within the scope of this invention.

Claims

1. A collimating lens, characterized in that: comprising a transmissive portion and / or a reflective portion, wherein the reflective portion is located at the periphery of the transmissive portion; The transmissive portion and the reflective portion form a receiving cavity for receiving the light source, the transmissive portion comprising a first surface and a second surface, the first surface being opposite to the second surface, and the second surface being located between the first surface and the receiving cavity; The reflecting portion includes a fifth surface connected to the first surface.

2. The collimating lens according to claim 1, wherein The first surface and the second surface are free-form surfaces; the first surface bulges in a direction away from the accommodating cavity, and the second surface bulges toward the accommodating cavity.

3. The collimating lens according to claim 2, wherein: The curvature of the first surface is greater than the curvature of the second surface.

4. The collimating lens according to claim 1, wherein The fifth surface is a free-form surface; The fifth surface protrudes toward the accommodating cavity.

5. The collimating lens according to claim 1, wherein: The first surface forms a first Fresnel lens, and / or the fifth surface forms a second Fresnel lens.

6. The collimating lens according to claim 1, wherein: The reflecting portion further includes a third surface and a fourth surface, wherein the third surface is connected to the second surface; The light incident on the reflective portion through the third surface is totally reflected on the fourth surface and then emitted from the fifth surface to the outside of the reflective portion.

7. The collimating lens according to claim 6, wherein: The third surface is a conical surface or a spherical surface.

8. The collimating lens according to claim 1, wherein: The transmission part and the reflection part are made of transparent optical plastic.

9. A collimation system, characterized in that: include: A light source and a collimating lens as described in any one of claims 1 to 8, wherein the light source is arranged in a receiving cavity of the collimating lens.

10. A method for designing a collimating lens, characterized in that: include: According to the position of the point light source and the positional relationship between the incident light and the outgoing light, a coordinate equation group of the first surface and the second surface is obtained; Obtaining coordinates of the first surface and the second surface according to the coordinate equation group, the starting point of the first surface, and the starting point of the second surface; The end point of the first surface is used as the starting point of the fifth surface, and the coordinates of the fifth surface are obtained according to the coordinate equation group of the first surface and the fifth surface, and the starting point of the fifth surface.

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