Projection optical structure, projection optical mirror surface adjustment method and projection lens

Abstract

This invention discloses a projection optical structure, a projection optical mirror adjustment method, and a projection lens, relating to the field of optical technology. The projection optical structure includes a light source and a first lens and a second lens arranged sequentially in the light-emitting direction of the light source. The first lens includes a first light-incident surface facing the light source, a first light-emitting surface facing the second lens, and a side surface located between the first light-incident surface and the first light-emitting surface. The second lens includes a second light-incident surface facing the first lens and a second light-emitting surface facing away from the first lens. A first stray ray emitted from the light source passes sequentially through the first light-incident surface, the side surface, the first light-emitting surface, the second light-incident surface, and the second light-emitting surface to form a first image point in the second lens. A second stray ray emitted from the light source passes sequentially through the first light-incident surface, the side surface, the first light-emitting surface, the second light-incident surface, and the second light-emitting surface to form a second image point at the bottom of the first image point.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a projection optical structure, a projection optical mirror adjustment method, and a projection lens. Background Technology

[0002] With the popularization of smart products and the advancement of technology, more products need to realize product interaction, and projection is a common way to achieve this. This method can display the simplest information interaction or scene rendering. There are many projection products on the market, such as projection speakers and projection alarm clocks.

[0003] Conventional projection solutions use traditional projection optics, but these non-projection products have somewhat unsightly optical lenses during interactive applications. Consumers have increasingly higher demands for products, requiring not only high-quality projection interaction but also specific form factors for the products themselves.

[0004] To address this need, companies in the market typically minimize or even hide the projection optical module, or integrate it into the product's appearance, making it difficult for consumers to observe the optical projection lens. However, this solution can easily reduce the projection effect and negatively impact the user experience. Summary of the Invention

[0005] The main objective of this invention is to propose a projection optical structure, a projection optical mirror adjustment method, and a projection lens, aiming to solve the technical problems in the prior art where the pursuit of aesthetics leads to an unreasonable design of the optical lens, making it impossible to reuse stray light for re-image formation within the optical system, and resulting in low optical utilization.

[0006] To achieve the above objectives, the present invention proposes a projection optical structure, including a light source and a first lens and a second lens arranged sequentially in the light-emitting direction of the light source;

[0007] The first lens includes a first light-incident surface disposed toward the light source, a first light-exiting surface disposed toward the second lens, and a side surface located between the first light-incident surface and the first light-exiting surface;

[0008] The second lens includes a second light-incident surface disposed toward one side of the first lens and a second light-outceasing surface disposed toward one side away from the first lens;

[0009] Wherein, the first stray light emitted by the light source passes sequentially through the first light-incident surface, the side surface, the first light-exiting surface, the second light-incident surface, and the second light-exiting surface, and then forms a first image point in the second lens;

[0010] The second stray light emitted by the light source passes sequentially through the first incident surface, the side surface, the first emitting surface, the second incident surface, and the second emitting surface, and then forms a second image point at the bottom of the first image point.

[0011] To address the aforementioned problems, this invention also proposes a projection optical mirror adjustment method, which is applied to the projection optical structure described above. The projection optical mirror adjustment method includes:

[0012] Obtain the first curvature of the upper surface of the first lens and the second curvature of the second light-emitting surface of the second lens;

[0013] Calculate the curvature difference based on the first curvature and the second curvature;

[0014] Adjust the surface profiles of the first lens and the second lens according to the curvature difference, so that the first stray ray of the light source forms a first image point in the second lens and the second stray ray of the light source forms a second image point in the second lens.

[0015] In addition, to solve the above problems, the present invention also proposes a projection lens, wherein the projection lens applies the projection optical structure as described above. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 An exploded view of the projection optical structure provided by this invention;

[0018] Figure 2 A schematic diagram of the optical path of the first stray ray in the projection optical structure provided by the present invention within the optical system;

[0019] Figure 3 A schematic diagram of the optical path of the second stray ray in the projection optical structure provided by the present invention within the optical system;

[0020] Figure 4 A schematic diagram showing the distance between the first image point and the second image point in the projection optical structure provided by the present invention;

[0021] Figure 5 This is a flowchart illustrating the first embodiment of the projection optical mirror adjustment method provided by the present invention.

[0022] Figure 6This is a flowchart illustrating the second embodiment of the projection optical mirror adjustment method provided by the present invention.

[0023] Explanation of icon numbers:

[0024] 10. First lens; 11. First light-incident surface; 12. First light-exiting surface; 13. Side surface; 20. Second lens; 21. Second light-incident surface; 22. Second light-exiting surface; 30. Light source; 31. Lamp bead; 32. Circuit board.

[0025] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0028] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0029] This invention proposes a projection optical structure. The projection optical structure includes a light source 30 and a first lens 10 and a second lens 20 sequentially arranged in the light-emitting direction of the light source 30; the first lens 10 includes a first light-incident surface 11 facing the light source 30, a first light-emitting surface 12 facing the second lens 20, and a side surface 13 located between the first light-incident surface 11 and the first light-emitting surface 12; the second lens 20 includes a second light-incident surface 21 facing the first lens 10 and a second light-emitting surface 22 facing away from the first lens 10.

[0030] The first stray light emitted by the light source 30 passes sequentially through the first light-incident surface 11, the side surface 13, the first light-outceasing surface 12, the second light-incident surface 21, and the second light-outceasing surface 22 before forming a first image point in the second lens 20.

[0031] The second stray light emitted by the light source 30 passes sequentially through the first incident surface 11, the side surface 13, the first emitting surface 12, the second incident surface 21, and the second emitting surface 22, and forms a second image point at the bottom of the first image point.

[0032] Please see Figure 1 In one embodiment of the present invention, the projection optical structure is a complete optical system. The light source 30 is placed at the bottom, with its light emission direction facing upward. The light source 30 includes a circuit board 32 and a plurality of lamp beads 31 disposed on the circuit board 32. The shape of the circuit board 32 can be circular, square, etc., as long as the circuit board 32 is on the optical axis of the optical system.

[0033] Multiple LED beads 31 are arranged in a matrix on the circuit board 32. When one or two rings of LED beads 31 located at the edge of the circuit board 32 emit light, their light is the edge light; while when other LED beads 31 located within the edge LED beads 31 emit light, their light is the center light.

[0034] In this embodiment, the first lens 10 is disposed above the light source 30, and the second lens 20 is disposed above the first lens 10. In this embodiment, the first lens 10 has a relatively high thickness, therefore, there is a side surface 13 in the middle of the first lens 10 that is connected to the bottom first light-incident surface 11 and the top first light-outceasing surface 12 respectively. The second lens 20 only includes the bottom second light-incident surface 21 and the top second light-outceasing surface 22.

[0035] The first lens 10 and the second lens 20 can be combined in various ways to improve the compatibility of the optical system and adapt to different application scenarios. For example, the first lens 10 can be a Fresnel lens, and the second lens 20 can be a concave-convex combination lens; or, the first lens 10 can be a plano-concave lens, and the second lens 20 can be a biconvex combination lens; or, the first lens 10 can be an irregularly shaped lens, and the second lens 20 can be a biconvex combination lens, etc.

[0036] Please refer to Figure 1 Part of the light from the light source 30 enters the first lens 10 through the first incident surface 11, is refracted, and exits the first lens 10 directly through the first exit surface 12. It then enters the second lens 20 through the second incident surface 21, is refracted by the second lens 20, and exits through the second exit surface 22. The second exit surface 22 is curved, and after the path of this part of the light is adjusted by the first lens 10 and the second lens 20, the light is focused, making the light output uniform and ensuring the projection effect.

[0037] Please continue to refer to Figure 2 However, even the light emitted by the LED 31 located at the center of the circuit board 32 will have some light (i.e., the first stray light) first hitting the side surface 13 of the first lens 10 after entering the first light-incident surface 11. Therefore, in this embodiment, the curved surface shape of the first lens 10 is adjusted through optical simulation. This causes total internal reflection on the side surface 13, and the light exits from the first light-exiting surface 12 after the first total internal reflection. It then enters the second lens 20 through the second light-incident surface 21. By adjusting the curved surface shape of the second lens 20, the first stray light undergoes total internal reflection on the second light-exiting surface 22. After the second total internal reflection, the light cannot exit normally from the second light-exiting surface 22, but instead converges in the second lens 20 to form an image point P1.

[0038] Specifically, when adjusting the curved surface shape of the first lens 10 and the second lens 20, the curvature of the first light-incident surface 11, the first light-exit surface 12, and the side surface 13 can be adjusted. Alternatively, the angle between the side surface 13 and the first light-incident surface 11 can be adjusted, or the angle between the first light-exit surface 12 and the side surface 13 can be adjusted.

[0039] Please continue to refer to Figure 3When the LED bead 31 located at the edge of the circuit board 32 emits light, most of the light (i.e., the second stray light) enters the first light-incident surface 11 and then illuminates the side surface 13 of the first lens 10. By adjusting the curved surface shape of the first lens 10, the light undergoes total internal reflection on the side surface 13. After the first total internal reflection, the light exits from the first light-exiting surface 12 and then enters the second lens 20 through the second light-incident surface 21. By adjusting the curved surface shape of the second lens 20, the second stray light undergoes total internal reflection on the second light-exiting surface 22. After the second total internal reflection, the light cannot exit normally from the second light-exiting surface 22 but converges in the second lens 20 to form an image point P2.

[0040] In this embodiment, since the centers of the first lens 10, the second lens 20, and the light source 30 are all located on the optical axis, when adjusting the curved surface shape of the first lens 10 and the second lens 20, it should also be ensured that the first image point P1 and the second image point P2 are also located on the optical axis.

[0041] The technical solution of this invention adjusts the curved surface shape of the first lens 10 and the second lens 20 to form a first image point P1 and a second image point P2 within the second lens. Optical simulation verification shows that the desired optical image can be obtained at a specified distance. Simultaneously, when viewed directly by the human eye, a clear microscopic projection with a certain depth can be seen within the second lens 20. Furthermore, as the viewing angle changes, the depth of the optical image also changes. Therefore, the depth of field can be adjusted to a certain level or even be eliminated as needed, resulting in different image effects when viewed from different angles within the optical system.

[0042] By reusing stray light, the product maintains its normal projection interaction function, allowing edge stray light to be re-imaged within the optical system. This improves the product's optical utilization and makes it more aesthetically pleasing.

[0043] It should be noted that, because the optical parameters used to adjust the curved surface shapes of the first lens 10 and the second lens 20 are different after optical simulation for the first stray ray and the second stray ray respectively, the optical indicators fluctuate, making it impossible to achieve a good projection effect.

[0044] Therefore, please refer to Figure 4In this embodiment, by measuring the distance L between the first image point P1 and the second image point P2, a curvature difference exists between the side surface 13 and the second light-emitting surface 22, and this curvature difference is positively correlated with the distance. The surface profiles of the first lens 10 and the second lens 20 are further adjusted based on the relationship between the distance L and the curvature difference. Specifically, adjustments can be made to the first light-incident surface 11, the side surface 13, the first light-emitting surface 12, the second light-incident surface 21, the second light-emitting surface 22, and the thickness of the first lens 10, thereby ensuring the final projection effect.

[0045] Furthermore, anti-reflective coatings can be applied to the first lens 10 and the second lens 20. Specifically, the first lens 10 has one or more coating areas, and coatings can be applied to different coating areas as needed to form the anti-reflective coating of the first lens 10. This anti-reflective coating can completely cover the first lens 10, cover any one coating area, or cover multiple different coating areas, etc.

[0046] A coating is applied to the second lens 20 to form an anti-reflection coating. The wavelength range of the anti-reflection coating on the second lens 20 should be selected to correspond to the wavelength of the light source 30, thereby improving the transmittance of the light beam from the light source 30 and enhancing the projection effect.

[0047] This invention also proposes a method for adjusting projection optical mirrors, which is applied to the projection optical structure described above. Please refer to [link to relevant documentation]. Figure 5 , Figure 5 This is a flowchart illustrating the first embodiment of the projection optical mirror adjustment method of the present invention, which specifically includes the following steps:

[0048] Step S10: Obtain the first curvature of the upper surface 13 of the first lens 10 and the second curvature of the second light-emitting surface 22 on the second lens 20;

[0049] Step S20: Calculate the curvature difference based on the first curvature and the second curvature;

[0050] Step S30: Adjust the surface profiles of the first lens 10 and the second lens 20 according to the curvature difference, so that the first stray light from the light source 30 forms a first image point in the second lens 20 and the second stray light from the light source 30 forms a second image point in the second lens 20.

[0051] Please refer to Figure 1Part of the light from the light source 30 enters the first lens 10 through the first incident surface 11, is refracted, and exits the first lens 10 directly through the first exit surface 12. It then enters the second lens 20 through the second incident surface 21, is refracted by the second lens 20, and exits through the second exit surface 22. The second exit surface 22 is curved, and after the path of this part of the light is adjusted by the first lens 10 and the second lens 20, the light is focused, making the light output uniform and ensuring the projection effect.

[0052] Please continue to refer to Figure 2 However, even the light emitted by the LED 31 located at the center of the circuit board 32 will have some light (i.e., the first stray light) first hitting the side surface 13 of the first lens 10 after entering the first light-incident surface 11. Therefore, in this embodiment, the curved surface shape of the first lens 10 is adjusted through optical simulation. This causes total internal reflection on the side surface 13, and the light exits from the first light-exiting surface 12 after the first total internal reflection. It then enters the second lens 20 through the second light-incident surface 21. By adjusting the curved surface shape of the second lens 20, the first stray light undergoes total internal reflection on the second light-exiting surface 22. After the second total internal reflection, the light cannot exit normally from the second light-exiting surface 22, but instead converges in the second lens 20 to form an image point P1.

[0053] Specifically, when adjusting the curved surface shape of the first lens 10 and the second lens 20, the curvature of the first light-incident surface 11, the first light-exit surface 12, and the side surface 13 can be adjusted. Alternatively, the angle between the side surface 13 and the first light-incident surface 11 can be adjusted, or the angle between the first light-exit surface 12 and the side surface 13 can be adjusted.

[0054] Please continue to refer to Figure 3 When the LED bead 31 located at the edge of the circuit board 32 emits light, most of the light (i.e., the second stray light) enters the first light-incident surface 11 and then illuminates the side surface 13 of the first lens 10. By adjusting the curved surface shape of the first lens 10, the light undergoes total internal reflection on the side surface 13. After the first total internal reflection, the light exits from the first light-exiting surface 12 and then enters the second lens 20 through the second light-incident surface 21. By adjusting the curved surface shape of the second lens 20, the second stray light undergoes total internal reflection on the second light-exiting surface 22. After the second total internal reflection, the light cannot exit normally from the second light-exiting surface 22 but converges in the second lens 20 to form an image point P2.

[0055] In this embodiment, since the centers of the first lens 10, the second lens 20, and the light source 30 are all located on the optical axis, when adjusting the curved surface shape of the first lens 10 and the second lens 20, it should also be ensured that the first image point P1 and the second image point P2 are also located on the optical axis.

[0056] The technical solution of this invention adjusts the curved surface shape of the first lens 10 and the second lens 20 to form a first image point P1 and a second image point P2 within the second lens. Optical simulation verification shows that the desired optical image can be obtained at a specified distance. Simultaneously, when viewed directly by the human eye, a clear microscopic projection with a certain depth can be seen within the second lens 20. Furthermore, as the viewing angle changes, the depth of the optical image also changes. Therefore, the depth of field can be adjusted to a certain level or even be eliminated as needed, resulting in different image effects when viewed from different angles within the optical system.

[0057] Further, please refer to Figure 6 , Figure 6 This is a flowchart illustrating the second embodiment of the projection optical mirror adjustment method of the present invention. Step S30 includes:

[0058] Step S31: Obtain the distance between the first image point and the second image point;

[0059] Step S32: Adjust the surface profiles of the first lens 10 and the second lens 20 according to the spacing and the curvature difference.

[0060] Because the optical parameters used to adjust the curved surface shapes of the first lens 10 and the second lens 20 are different after optical simulation for the first stray ray and the second stray ray respectively, the optical indicators fluctuate, making it impossible to achieve a good projection effect.

[0061] Therefore, please refer to Figure 4 In this embodiment, by measuring the distance L between the first image point P1 and the second image point P2, a curvature difference exists between the side surface 13 and the second light-emitting surface 22, and this curvature difference is positively correlated with the distance. The surface profiles of the first lens 10 and the second lens 20 are further adjusted based on the relationship between the distance L and the curvature difference. Specifically, adjustments can be made to the first light-incident surface 11, the side surface 13, the first light-emitting surface 12, the second light-incident surface 21, the second light-emitting surface 22, and the thickness of the first lens 10, thereby ensuring the final projection effect.

[0062] The present invention also proposes a projection lens, which applies the projection optical structure as described above. The specific structure of the projection optical structure is as described in the above embodiments. Since the projection lens adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0063] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A projection optical structure, characterized in that, The projection optical structure includes a light source and a first lens and a second lens arranged sequentially in the light-emitting direction of the light source. The first lens includes a first light-incident surface disposed toward the light source, a first light-exiting surface disposed toward the second lens, and a side surface located between the first light-incident surface and the first light-exiting surface; The second lens includes a second light-incident surface disposed toward one side of the first lens and a second light-outceasing surface disposed toward one side away from the first lens; Wherein, the first stray light emitted by the light source passes sequentially through the first light-incident surface, the side surface, the first light-exiting surface, the second light-incident surface, and the second light-exiting surface, and then forms a first image point in the second lens; The second stray light emitted by the light source passes sequentially through the first incident surface, the side surface, the first emitting surface, the second incident surface, and the second emitting surface, and then forms a second image point at the bottom of the first image point; The light source includes a circuit board and a plurality of LEDs disposed on the circuit board. The first stray light is the light emitted by the LED located at the center of the circuit board; the second stray light is the light emitted by the LED located at the edge of the circuit board.

2. The projection optical structure as described in claim 1, characterized in that, The first incident light surface and the side surface have a first included angle, and the first exiting light surface and the side surface have a second included angle, so that after the first stray light and / or the second stray light enter the first lens through the first incident light surface, total internal reflection occurs on the side surface, and the reflected light is emitted from the first exiting light surface into the second lens.

3. The projection optical structure as described in claim 1, characterized in that, The second light-emitting surface is convex and arc-shaped towards the side opposite to the first lens, so that the first stray light and / or the second stray light enter the second lens from the second light-incident surface, undergo total internal reflection on the second light-emitting surface, and are focused within the second lens.

4. The projection optical structure as described in claim 1, characterized in that, There is a curvature difference between the side surface and the second light-emitting surface, and there is a spacing between the first image point and the second image point. The curvature difference and the spacing are positively correlated.

5. The projection optical structure as described in claim 1, characterized in that, The projection optical structure includes an optical axis, and the center points of the light source, the first lens, and the second lens are all located on the optical axis. The first image point and the second image point are both located on the optical axis.

6. The projection optical structure as described in claim 1, characterized in that, The first lens is a Fresnel lens, and the second lens is a combination of concave and convex lenses; or, The first lens is a plano-concave lens, and the second lens is a combination of biconvex and non-convex lenses; or, In the first lens, which is an irregularly shaped lens, the second lens is a biconvex combination lens.

7. The projection optical structure as described in claim 1, characterized in that, The light source includes multiple LED beads, which are arranged in a matrix.

8. A method for adjusting a projection optical mirror, characterized in that, The projection optical mirror adjustment method is applied to the projection optical structure as described in any one of claims 1 to 7, and the projection optical mirror adjustment method includes: Obtain the first curvature of the upper surface of the first lens and the second curvature of the second light-emitting surface of the second lens; Calculate the curvature difference based on the first curvature and the second curvature; Adjust the surface profiles of the first lens and the second lens according to the curvature difference, so that the first stray ray of the light source forms a first image point in the second lens and the second stray ray of the light source forms a second image point in the second lens.

9. The projection optical mirror adjustment method as described in claim 8, characterized in that, The steps of adjusting the surface profiles of the first lens and the second lens based on the curvature difference include: Obtain the distance between the first image point and the second image point; The surface profiles of the first lens and the second lens are adjusted according to the spacing and the curvature difference; The spacing and the curvature difference are positively correlated.

10. A projection lens, characterized in that, The projection lens employs the projection optical structure as described in any one of claims 1 to 7.

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