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

Abstract

The invention discloses a projection optical structure, a projection optical mirror surface adjusting method and a projection lens, and relates to the technical field of optics, the projection optical structure comprises a light source, and a first lens and a second lens which are sequentially arranged in the light emitting direction of the light source; the first lens comprises a first light incident surface arranged towards one side of the light source, a first light emergent surface arranged towards one side of the second lens, and a side surface positioned between the first light incident surface and the first light emergent surface; the second lens comprises a second light incident surface arranged towards one side of the first lens and a second light emergent surface arranged towards one side deviating from the first lens; wherein first stray light emitted by the light source sequentially passes through the first light incident surface, the side surface, the first light emergent surface, the second light incident surface and the second light emergent surface and then forms a first image point in the second lens; second stray light emitted by the light source sequentially passes through the first incident surface, the side surface, the first emergent surface, the second incident surface and the second emergent surface and then forms a second image point at the bottom of the first image point.

Description

Technical Field

[0001] The present 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 Art

[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 realize interaction. This method shows the simplest information interaction or scene rendering. There are many projection products on the market, such as projection speakers, projection alarm clocks, etc.

[0003] General projection solutions use traditional projection optical solutions, but these non-projection products have certain unsightly optical lenses during the application interaction process. Consumers have increasingly higher demands for products, requiring not only the quality of projection interaction, but also the form of the product itself.

[0004] Based on this demand, companies on the market generally make the projection optical module smaller or even hidden, or integrate it with the product appearance, making it difficult for consumers to observe the existence of the optical projection lens. However, this solution can easily reduce the projection effect and affect the user experience. Summary of the invention

[0005] The main purpose of the present 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 that in pursuit of aesthetics, the volume of the optical lens is compressed, resulting in unreasonable design, the inability to reuse stray light to form an image again in the optical system, and the low optical utilization rate.

[0006] To achieve the above object, the present invention provides a projection optical structure, comprising a light source and a first lens and a second lens sequentially arranged in the light emitting direction of the light source;

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

[0008] The second lens comprises a second light incident surface disposed toward a side of the first lens and a second light emitting surface disposed toward a side away from the first lens;

[0009] Wherein, the first stray light emitted by the light source forms a first image point in the second lens after passing 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 in sequence;

[0010] The second stray light emitted by the light source passes 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 in sequence to form a second image point at the bottom of the first image point.

[0011] In order to solve the above problems, the present invention further proposes a projection optical mirror adjustment method, which is applied to the projection optical structure as described above, and the projection optical mirror adjustment method comprises:

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

[0013] calculating a curvature difference according to the first curvature and the second curvature;

[0014] The curved surface shapes of the first lens and the second lens are adjusted according to the curvature difference so that the first stray light of the light source forms a first image point in the second lens and the second stray light of the light source forms a second image point in the second lens.

[0015] In addition, to solve the above problem, the present invention further provides a projection lens, wherein the projection lens is applied with the above-mentioned projection optical structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 the structures shown in these drawings without paying creative work.

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

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

[0020] Figure 4 A schematic diagram of 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 A schematic diagram of the flow chart of the first embodiment of the projection optical mirror adjustment method provided by the present invention;

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

[0023] Description of Figure Numbers:

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

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

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work 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 position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The present invention provides a projection optical structure. The projection optical structure includes a light source 30 and a first lens 10 and a second lens 20 arranged in sequence in the light emitting direction of the light source 30; the first lens 10 includes a first light incident surface 11 arranged toward the light source 30, a first light emitting surface 12 arranged toward 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 arranged toward the first lens 10, and a second light emitting surface 22 arranged toward the side away from the first lens 10.

[0030] The first stray light emitted by the light source 30 passes through the first light incident surface 11, the side surface 13, the first light emitting surface 12, the second light incident surface 21, and the second light emitting surface 22 in sequence, and then forms a first image point in the second lens 20;

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

[0032] See also Figure 1 In one embodiment of the present invention, the projection optical structure is a whole optical system. The light source 30 is placed at the bottom, and its light emitting direction is upward. The light source 30 includes a circuit board 32 and a plurality of lamp beads 31 arranged 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 lamp beads 31 are distributed in a matrix on the circuit board 32. When one or two circles of lamp beads 31 located at the edge of the circuit board 32 emit light, their light is edge light; and when other lamp beads 31 surrounded by the edge lamp beads 31 emit light, their light is 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, and therefore, there is a side surface 13 in the middle of the first lens 10 that is respectively connected to the bottom first light incident surface 11 and the top first light emitting surface 12. The second lens 20 only includes the bottom second light incident surface 21 and the top second light emitting surface 22.

[0035] The first lens 10 and the second lens 20 can be combined in a variety of different structures to improve the compatibility of the optical system and adapt to various 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 double-convex combination lens; or, the first lens 10 can be a special-shaped lens, and the second lens 20 can be a double-convex combination lens, etc.

[0036] Please refer to Figure 1 Part of the light from the light source 30 enters the first lens 10 from the first light incident surface 11, is refracted and directly emitted from the first lens 10 through the first light emitting surface 12, and enters the second lens 20 from the second light incident surface 21. After being refracted by the second lens 20, it is emitted from the second light emitting surface 22. The second light emitting surface 22 is a curved surface, and the first lens 10 and the second lens 20 adjust the path of the part of the light to gather the light, so that the light is evenly emitted, ensuring the projection effect.

[0037] Please continue to refer to Figure 2 However, even for the light emitted by the lamp bead 31 located at the center of the circuit board 32, part of the light (that is, the first stray light) will first irradiate 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. The light is totally reflected on the side surface 13, and then the light is emitted from the first light emitting surface 12 after the first total reflection. And then it is incident into the second lens 20 through the second light incident surface 21, and the curved surface shape of the second lens 20 is adjusted so that the first stray light is totally reflected on the second light emitting surface 22. Then, after the second total reflection, the light cannot be emitted normally from the second light emitting surface 22, but converges in the second lens 20 and forms an image point P1.

[0038] Specifically, when adjusting the curved surface profiles of the first lens 10 and the second lens 20, the curvatures of the first light incident surface 11, the first light emitting surface 12, and the side surface 13 may be adjusted. Alternatively, the first angle between the side surface 13 and the first light incident surface 11 may be adjusted, and the second angle between the first light emitting surface 12 and the side surface 13 may be adjusted.

[0039] Please continue to refer to Figure 3When the lamp bead 31 located at the edge of the circuit board 32 emits light, most of the light (that is, the second stray light) is irradiated on the side surface 13 of the first lens 10 after entering the first light incident surface 11. By adjusting the curved surface shape of the first lens 10. The light is totally reflected on the side surface 13, and then the light is emitted from the first light emitting surface 12 after the first total reflection. And then it is emitted into the second lens 20 through the second light incident surface 21, and the curved surface shape of the second lens 20 is adjusted so that the second stray light is totally reflected on the second light emitting surface 22. Then, after the second total reflection, the light cannot be emitted normally from the second light emitting surface 22, but converges in the second lens 20 and forms 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 shapes of the first lens 10 and the second lens 20, it should 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 the present invention adjusts the curved surface of the first lens 10 and the second lens 20 so that the first image point P1 and the second image point P2 are formed in the second lens. The optical simulation verification can achieve the desired optical image at a specified distance. At the same time, when the human eye looks directly, a clear microscopic projection with a certain sense of depth can be seen in the second lens 20. As the human eye changes the observation angle, the depth of the optical image will also change. Therefore, the depth of field can be adjusted to a certain depth of field or no depth of field according to the needs, so that different image effects can be seen in the optical system at different angles.

[0042] By reusing stray light, the product can ensure normal projection interaction function, and the edge stray light can be re-imaged in the optical system, thus improving the optical utilization rate of the product and making the product more beautiful.

[0043] It should be noted that, because the optical parameters of the curved surfaces of the first lens 10 and the second lens 20 are adjusted according to the optical simulation for the first stray light and the second stray light respectively, the optical parameters are different, which causes the fluctuation of the optical indicators and fails 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, there is a curvature difference between the side surface 13 and the second light exiting surface 22, and the curvature difference and the distance are positively correlated. The curved surface of the first lens 10 and the second lens 20 can be further adjusted by the relationship between the distance L and the curvature difference. Specifically, the first light incident surface 11, the side surface 13, the first light exiting surface 12, the second light incident surface 21, the second light exiting surface 22 and the thickness of the first lens 10 can be adjusted. Thereby ensuring the final projection effect.

[0045] In addition, a lens anti-reflection film may be provided on the first lens 10 and the second lens 20. Specifically, the first lens 10 has one or more coating areas, and coating may be performed on different coating areas as required to form an anti-reflection film on the first lens 10. The anti-reflection film on the first lens 10 may cover and wrap the entire first lens 10, or may cover any coating area, or may cover multiple different coating areas, etc.

[0046] The second lens 20 is coated to form an anti-reflection film for the second lens 20. The wavelength range of the anti-reflection film for the second lens 20 should be selected to correspond to the wavelength of the light source 30, so as to improve the transmittance of the light beam of the light source 30 and improve the projection effect.

[0047] The present invention also provides a projection optical mirror adjustment method, which is applied to the projection optical structure as described above. Figure 5 , Figure 5 This is a flow chart of a first embodiment of a projection optical mirror adjustment method of the present invention, which specifically includes the following steps:

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

[0049] Step S20: calculating a curvature difference according to the first curvature and the second curvature;

[0050] Step S30: adjusting the curved surface shapes of the first lens 10 and the second lens 20 according to the curvature difference, so that the first stray light of the light source 30 forms a first image point in the second lens 20, and the second stray light of 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 from the first light incident surface 11, is refracted and directly emitted from the first lens 10 through the first light emitting surface 12, and enters the second lens 20 from the second light incident surface 21. After being refracted by the second lens 20, it is emitted from the second light emitting surface 22. The second light emitting surface 22 is a curved surface, and the first lens 10 and the second lens 20 adjust the path of the part of the light to gather the light, so that the light is evenly emitted, ensuring the projection effect.

[0052] Please continue to refer to Figure 2 However, even for the light emitted by the lamp bead 31 located at the center of the circuit board 32, part of the light (that is, the first stray light) will first irradiate 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. The light is totally reflected on the side surface 13, and then the light is emitted from the first light emitting surface 12 after the first total reflection. And then it is incident into the second lens 20 through the second light incident surface 21, and the curved surface shape of the second lens 20 is adjusted so that the first stray light is totally reflected on the second light emitting surface 22. Then, after the second total reflection, the light cannot be emitted normally from the second light emitting surface 22, but converges in the second lens 20 and forms an image point P1.

[0053] Specifically, when adjusting the curved surface profiles of the first lens 10 and the second lens 20, the curvatures of the first light incident surface 11, the first light emitting surface 12, and the side surface 13 may be adjusted. Alternatively, the first angle between the side surface 13 and the first light incident surface 11 may be adjusted, and the second angle between the first light emitting surface 12 and the side surface 13 may be adjusted.

[0054] Please continue to refer to Figure 3 When the lamp bead 31 located at the edge of the circuit board 32 emits light, most of the light (that is, the second stray light) is irradiated on the side surface 13 of the first lens 10 after entering the first light incident surface 11. By adjusting the curved surface shape of the first lens 10. The light is totally reflected on the side surface 13, and then the light is emitted from the first light emitting surface 12 after the first total reflection. And then it is emitted into the second lens 20 through the second light incident surface 21, and the curved surface shape of the second lens 20 is adjusted so that the second stray light is totally reflected on the second light emitting surface 22. Then, after the second total reflection, the light cannot be emitted normally from the second light emitting surface 22, but converges in the second lens 20 and forms 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 shapes of the first lens 10 and the second lens 20, it should 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 the present invention adjusts the curved surface of the first lens 10 and the second lens 20 so that the first image point P1 and the second image point P2 are formed in the second lens. The optical simulation verification can achieve the desired optical image at a specified distance. At the same time, when the human eye looks directly, a clear microscopic projection with a certain sense of depth can be seen in the second lens 20. As the human eye changes the observation angle, the depth of the optical image will also change. Therefore, the depth of field can be adjusted to a certain depth of field or no depth of field according to the needs, so that different image effects can be seen in the optical system at different angles.

[0057] For further information, see Figure 6 , Figure 6 This is a flow chart of a second embodiment of the projection optical mirror adjustment method of the present invention, step S30 includes:

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

[0059] Step S32: adjusting the curved surface shapes of the first lens 10 and the second lens 20 according to the distance and the curvature difference.

[0060] Because after the optical simulation is performed to adjust the curved surface of the first lens 10 and the second lens 20 according to the first stray light and the second stray light, the optical parameters are different, which causes the fluctuation of the optical index and fails 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, there is a curvature difference between the side surface 13 and the second light exiting surface 22, and the curvature difference and the distance are positively correlated. The curved surface of the first lens 10 and the second lens 20 can be further adjusted by the relationship between the distance L and the curvature difference. Specifically, the first light incident surface 11, the side surface 13, the first light exiting surface 12, the second light incident surface 21, the second light exiting surface 22 and the thickness of the first lens 10 can be adjusted. Thereby ensuring the final projection effect.

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

[0063] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A projection optical structure, characterized in that: The projection optical structure comprises a light source and a first lens and a second lens arranged in sequence in the light emitting direction of the light source; The first lens comprises a first light incident surface disposed toward the light source, a first light emitting surface disposed toward the second lens, and a side surface located between the first light incident surface and the first light emitting surface; The second lens comprises a second light incident surface disposed toward a side of the first lens and a second light emitting surface disposed toward a side away from the first lens; Wherein, the first stray light emitted by the light source forms a first image point in the second lens after passing 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 in sequence; The second stray light emitted by the light source passes 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 in sequence to form a second image point at the bottom of the first image point.

2. The projection optical structure according to claim 1, characterized in that: A first angle is formed between the first light incident surface and the side surface, and a second angle is formed between the first light emitting surface and the side surface, so that after the first stray light and / or the second stray light enters the first lens through the first light incident surface, total reflection occurs on the side surface, and the reflected light is emitted from the first light emitting surface to the second lens.

3. The projection optical structure according to claim 1, characterized in that: The second light emitting surface is convex and arc-shaped toward a side away from the first lens, so that after the first stray light and / or the second stray light enters the second lens from the second light incident surface, it is totally reflected on the second light emitting surface and focused in the second lens.

4. The projection optical structure according to claim 1, characterized in that: There is a curvature difference between the side surface and the second light emitting surface, there is a distance between the first image point and the second image point, and the curvature difference and the distance are positively correlated with each other.

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

6. The projection optical structure according to claim 1, characterized in that: The first lens is a Fresnel lens, and the second lens is a concave-convex combined lens; or, The first lens is a plano-concave lens, and the second lens is a biconvex combined lens; or, The first lens is a special-shaped lens, and the second lens is a double-convex combination lens.

7. The projection optical structure according to claim 1, characterized in that: The light source includes a plurality of lamp beads, and the plurality of lamp beads are arranged in a matrix distribution.

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 according to any one of claims 1 to 7, and the projection optical mirror adjustment method comprises: Obtaining a first curvature of an upper surface of the first lens and a second curvature of a second light-emitting surface of the second lens; calculating a curvature difference according to the first curvature and the second curvature; The curved surface shapes of the first lens and the second lens are adjusted according to the curvature difference so that the first stray light of the light source forms a first image point in the second lens and the second stray light of the light source forms a second image point in the second lens.

9. The projection optical mirror adjustment method according to claim 8, characterized in that: The step of adjusting the curved surface shapes of the first lens and the second lens according to the curvature difference comprises: Acquire a distance between the first image point and the second image point; Adjusting the curved surface shapes of the first lens and the second lens according to the distance and the curvature difference; The spacing and the curvature difference are positively correlated with each other.

10. A projection lens, characterized in that: The projection lens is applied with the projection optical structure as claimed in any one of claims 1 to 7.

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