Dynamic multi-spot projection optical system based on LED light source

Abstract

The invention discloses a dynamic multi-spot projection optical system based on an LED light source, which comprises the LED light source, a reflecting cover, a grating sheet, a condensing lens, a concave reflector and an optical reflection assembly, and is characterized in that the LED light source is arranged at the bottom of the reflecting cover, and the grating sheet is provided with a light-transmitting area with a preset pattern shape; the reflecting cover consists of a plurality of plane reflectors A; the concave reflector consists of a plurality of plane reflectors B; light emitted by the LED light source forms a pattern light beam through the grating piece, the light beam is divided and reflected into a plurality of sub light beams through the conical reflecting cover, and the sub light beams are guided to the condensing lens through the optical reflecting mirror set. According to the invention, a low-cost, laser-free and safe LED scheme is adopted, and through innovative optical design, a complex dynamic light and shadow effect comparable to or even surpassing laser projection is realized, and the imaging definition is kept unchanged within a projection distance range of 2-15 meters.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of LED projection technology, and in particular to a dynamic multi-spot projection optical system based on an LED light source. BACKGROUND

[0002] The dynamic multi-spot projection device is widely used to create special light and shadow effects. In the prior art, there is a system scheme that uses a laser light source to cooperate with a diffractive optical element (DOE) to realize multi-spot projection. However, this scheme has problems such as high cost of laser, eye safety risk, and speckle noise caused by laser coherence, and it is difficult to realize the projection of irregular patterns with clear edges.

[0003] In addition, another scheme uses an LED array to realize multi-spot projection by imaging multiple LED chips respectively. However, this scheme requires complex circuit control and heat dissipation design, has high system cost, and is difficult to realize the dynamic rotation effect of the light spot.

[0004] As a non-coherent light source, although the LED has the advantages of low cost and good safety, its Lambertian emission characteristic leads to a large light divergence angle. In the prior art scheme such as CN201820987654.3, a conventional spherical lens group is used for beam shaping, which is difficult to correct the spherical aberration, astigmatism and field curvature caused by the large-angle light at the same time, resulting in blurred edges of the projected light spot and poor overall uniformity.

[0005] Therefore, there is an urgent need in the art for a new optical system that can overcome the problems of strong divergence and severe aberration of LED light sources, and realize high-density and high-definition dynamic multi-spot projection. SUMMARY

[0006] The technical problem to be solved by the embodiments of the present application is to provide a dynamic multi-spot projection optical system based on an LED light source, which can project complex non-circular patterns at low cost, high efficiency and high definition, and realize dynamic rotation effect, while solving the problems of low light collection efficiency and severe aberration caused by the Lambertian emission of the LED.

[0007] To solve the above technical problems, the embodiments of the present application provide a dynamic multi-spot projection optical system based on an LED light source, which comprises an LED light source, a reflector, a grating sheet, a condenser lens, a concave mirror, and an optical reflection assembly. The LED light source is arranged at the bottom of the reflector, the grating sheet is arranged above the LED light source, and the grating sheet is provided with a light-transmitting area in a predetermined pattern shape. The reflector is composed of a plurality of plane mirrors A, which are sequentially connected to form a conical reflecting surface. The concave mirror is composed of a plurality of plane mirrors B. The optical reflection assembly reflects the light reflected by the reflector to the condenser lens, and then the light is reflected by the concave mirror after being condensed by the condenser lens.

[0008] Furthermore, it also includes a grating turntable, with several grating plates arranged around the center of the turntable. The grating plates above the LED light source are switched by rotating the grating turntable.

[0009] Furthermore, the optical reflection assembly consists of a plane mirror A and a plane mirror B. The plane mirror A is positioned above the reflector, and the plane mirror B is positioned in front of the plane mirror A. The plane mirror A reflects the light reflected from the reflector to the plane mirror B, and then the plane mirror B reflects the light to the condenser lens.

[0010] Furthermore, a light-blocking plate is provided between the condenser lens and the reflector.

[0011] Furthermore, the condenser lens adopts a biconvex aspherical structure, where both its front and rear surfaces are even-order aspherical surfaces, and satisfy the following conditions: The focal length is 162.99mm±5%, the radius of curvature of the front surface is 26180mm±5%, the radius of curvature of the rear surface is 80.214mm±5%, the conicity of the front surface is k=37.527±5%, the conicity of the rear surface is k=-0.9545±5%, and the center thickness is 5.1325mm±5%.

[0012] Furthermore, the refractive index of the condenser lens is 1.493±5%, and the Abbe number is 57.2±5%.

[0013] Furthermore, the preset pattern shape is one or more of the following: maple leaf shape, snowflake shape, star shape, cloud shape, and swastika shape.

[0014] Furthermore, it also includes a rotary drive module, with a concave reflector correspondingly mounted on the output shaft of the rotary drive module.

[0015] Furthermore, the concave mirror is a parabolic mirror.

[0016] Furthermore, the reflector includes n planar mirrors A, and the concave mirror includes m planar mirrors B. The n+1 light spots of a preset pattern shape reflected by the optical reflection component are used as a projection unit. The dynamic multi-spot projection optical system based on LED light source satisfies the following equation: 0.6× delta < (X×360° / m) < delta ; Where X represents the angular magnification of the entire optical system of the dynamic multi-spot projection optical system based on LED light source. delta The angular diameter of a single projection unit on the projection plane.

[0017] The beneficial effects of this invention are as follows: 1. Safety and cost advantage: The present application uses ordinary LED light source, avoids high laser and strict safety certification, reduces cost by more than 50%, and is safer to apply.

[0018] 2. Functional and performance advantage: (1) The present application realizes clear projection of complex patterns (such as snowflakes and maple leaves), overcoming the problem of laser speckle; (2) The present application corrects aberration very well through double-convex aspheric condenser lens, ensuring clear edge of light spot; (3) The optical system of the present application has a large depth of field, and the clarity does not change when the projection distance changes in the range of 2-15 meters, with very high installation flexibility.

[0019] 3. Technical originality: The present application successfully applies LED light source to dynamic multi-spot projection of high-density complex patterns for the first time through the combination of "multi-plane mirror light splitting system" and "customized aspheric lens aberration correction system", realizing direct replacement and functional transcendence of laser scheme.

[0020] 4. Commercial value: The present application reduces the manufacturing threshold and cost, laying a foundation for the popularization of complex light and shadow effects in smart home, atmosphere lighting, commercial display and other fields. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a perspective view of one angle of the dynamic multi-spot projection optical system based on LED light source of an embodiment of the present application.

[0022] Figure 2 is a perspective view of another angle of the dynamic multi-spot projection optical system based on LED light source of an embodiment of the present application.

[0023] Figure 3 is a perspective view of the reflector of an embodiment of the present application.

[0024] Figure 4 is a perspective view of the grating turntable of an embodiment of the present application.

[0025] Figure 5 is a perspective view of the LED light source of an embodiment of the present application.

[0026] Figure 6 is an aberration curve of the condenser lens of the present application at wavelengths of 486nm, 587nm and 656nm.

[0027] Figure 7 is a comparison chart of modulation transfer function (MTF) curves of the optical system of the present application at projection distances of 2 meters, 8 meters and 15 meters.

[0028] EXPLANATION OF REFERENCE NUMBERS 1, light shield, 2, grating sheet, 3, condenser lens, 4, concave mirror, 5, rotating drive module, 6, base, 7, plane mirror A, 8, plane mirror B, 9, plane mirror A, 10, plane mirror B, 11, rotating shaft, 12, light shield, 13, LED light source, 14, grating turntable, 15, base plate, 16, LED. DETAILED DESCRIPTION

[0029] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict, and the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0030] If there is a directional indication (such as up, down, left, right, front, back, etc.) in the embodiments of the present application, it is only used to explain the relative position relationship, motion condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indication also changes accordingly.

[0031] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features.

[0032] Please refer to Figures 1-5 The dynamic multi-spot projection optical system based on the LED light source of the embodiment of the present application includes an LED light source, a light shield, a grating sheet, a condenser lens, a concave mirror, an optical reflection assembly, a rotating drive module, and a base.

[0033] The LED light source, the light shield, the condenser lens, the concave mirror, the optical reflection assembly, and the rotating drive module are arranged on the base. The LED light source is located at the bottom of the light shield and is used to emit incoherent light.

[0034] The grating sheet is correspondingly arranged above the LED light source and is closely arranged with the LED light source. The grating sheet is provided with a light-transmitting area (non-circular) of a preset pattern shape. The light emitted by the LED light source forms a light spot of a preset pattern shape through the light-transmitting area. The LED light source is a single-point LED light source.

[0035] The light-reflecting cover is composed of a plurality of plane mirrors A, which are sequentially connected to form a conical reflecting surface for reflecting and splitting the light beam passing through the light-transmitting area into a plurality of sub-beams. The light-reflecting cover includes n plane mirrors A. The light-reflecting cover reflects n light spots of preset pattern shapes to an optical reflecting assembly (i.e., the plane mirror A). The optical reflecting assembly reflects the n light spots of preset pattern shapes reflected by the light-reflecting cover and a light spot of preset pattern shape passing through the grating sheet, i.e., a total of n+1 light spots of preset pattern shapes. The light spot of preset pattern shape passing through the grating sheet is distributed in the ring of the n light spots of preset pattern shapes reflected by the light-reflecting cover, and the n+1 light spots form a projection unit. The taper (i.e., the inclination angle) of the plane mirror A affects the distance between the peripheral n light spots and the central light spot of the projection unit.

[0036] The optical reflecting assembly reflects the light reflected by the light-reflecting cover to a condenser lens, and the light is reflected by a concave mirror after being condensed by the condenser lens. The optical reflecting assembly includes at least two plane mirrors for changing the direction of the light path to shorten the total optical path of the system. The condenser lens is used for imaging the plurality of sub-beams.

[0037] The concave mirror is composed of a plurality of plane mirrors B. The concave mirror is used for reflecting and projecting the imaged light beam to a projection surface to form a plurality of light spots of preset pattern shapes. The concave mirror includes m plane mirrors B, and the projection unit is reflected by the m plane mirrors B to the projection surface to form m projection units, i.e., a total of m×(n+1) light spots of preset pattern shapes. The concave mirror is a parabolic mirror. The curvature of the concave mirror affects the spacing between the m projection units.

[0038] The concave mirror is arranged on the output shaft of a rotary driving module. The rotary driving module can adopt a direct-current speed reducer. The rotary driving module drives the concave mirror, so that the projection pattern on the projection surface moves, and an atmosphere of starlight flowing can be generated.

[0039] The condenser lens is made of optical-grade PMMA or polycarbonate material. The condenser lens adopts a biconvex aspheric structure, and both the front surface and the rear surface (in the direction of light path transmission) are even aspheric surfaces. The surface z function of the condenser lens satisfies: ; wherein c is the curvature, the reciprocal of the radius; r is the radial coordinate, k is the conic coefficient; is the even aspheric coefficient, corresponding to the order, i is a positive integer.

[0040] The parameters of the condenser lens satisfy: The focal length is 162.99mm±5%, the front surface curvature radius is 26180mm±5%, the rear surface curvature radius is 80.214mm±5%, the front surface conic coefficient k=37.527±5%, and the rear surface conic coefficient k=-0.9545±5%, and the center thickness is 5.1325mm±5%.

[0041] The wavelength range of the LED light source is 486nm-656nm, the refractive index of the condenser lens is 1.493±5%, and the Abbe number is 57.2±5%. The simulation verification of the application shows that the maximum spherical aberration is less than 0.1mm and the field curvature is less than 0.5% in the wavelength range of 486nm-656nm. Due to the manufacturing tolerance of the optical element and the tolerance distribution of the optical system, the optical system of the application can still maintain its excellent aberration correction function and depth of field characteristics when the above parameters vary within the range of ±5%. The application solves the contradiction between the large-angle light emission of the LED and the clear imaging of multiple light spots through the specific combination of parameters, which is the core of the application.

[0042] The modulation transfer function of the optical system of the application is greater than 0.4 at a spatial frequency of 20lp / mm in a projection distance range of 2-15m, and the total length of the optical system is less than 200mm.

[0043] The application can achieve the following technical effects through the specific optical design of the biconvex aspheric condenser lens and the cooperation with the conical light splitting structure: 1. Excellent aberration correction ability: the combination of aspheric coefficients and curvature radii of the application is optimized, which can well correct the spherical aberration and astigmatism caused by the large divergence angle of the LED light source and the light splitting of the conical reflector, and ensure that the edges of hundreds of pattern light spots on the projection surface remain clear. The Strehl ratio of the measured projection light spot is greater than 0.8, which is much better than the conventional spherical lens system (usually less than 0.6).

[0044] 2. "Focus depth extension" effect: the lens design of the application makes the optical system have a large depth of field, and the imaging clarity does not change (the MTF value changes less than 10%) when the projection distance changes in the range of 2-15m, only the size of the image changes proportionally, which significantly improves the installation flexibility. This feature is achieved through a specific combination of aspheric coefficients, which can maintain stable imaging quality in a large range.

[0045] 3. System matching: the focal length of the lens of the application matches the optical path design, ensures that the total length of the system is compact (less than 200mm), and can be matched with a concave reflector to accurately project the image plane to the expected distance.

[0046] The grating sheet of the present application can only adopt one grating sheet, and in the specific implementation, can be directly integrated in the LED light source (i.e. the top of the LED, instead of the original lens of the top of the LED). The LED light source is composed of a substrate and an LED, and the substrate is an aluminum nitride ceramic substrate or a copper substrate. A plurality of grating sheets can also be adopted, and a grating carousel is used to integrate the plurality of grating sheets on the grating carousel, i.e. the plurality of grating sheets are arranged around the center of the grating carousel. The shapes of the light transmission regions on the grating sheets on the grating carousel are different, and the grating sheet above the LED light source is switched by rotating the grating carousel, so as to realize the switching of the projected pattern. In the specific implementation, the grating carousel can be arranged on the base through a rotating shaft. The grating carousel can be manually controlled or electrically controlled, if manually controlled, a rotating handle can be connected to the bottom of the rotating shaft, and if electrically controlled, the rotating shaft can be directly connected to a micro motor, and the motor drives the switching of the pattern.

[0047] As an embodiment, the optical reflection assembly is composed of a plane mirror A and a plane mirror B, the plane mirror A is arranged directly above the light shield, and the plane mirror B is arranged in front of the plane mirror A, the plane mirror A reflects the light reflected by the light shield to the plane mirror B, and then the light is reflected to the condenser lens by the plane mirror B. The optical reflection assembly is composed of two plane mirrors, so that the whole optical system of the dynamic multi-spot projection optical system based on the LED light source of the present application is more simple.

[0048] As an embodiment, a light blocking plate is arranged between the condenser lens and the light shield. The light blocking plate prevents light leakage, blocks the stray light reflected by the diffuse reflection, and prevents the stray light from interfering with the projected pattern.

[0049] As an embodiment, the LED chip is a single-color light source or a multi-color light source, so that the projected pattern is single-color or multi-color.

[0050] As an implementation, the preset pattern shape is one or more of maple leaf shape, snowflake shape, star shape, cloud shape and swastika shape. For example, when the preset pattern shape is maple leaf shape, the LED chip can adopt yellow / orange red light source, is projected to the projection surface (generally the ceiling or wall) through the light path system of the application, and then is driven to move by the rotary drive module, so as to create the atmosphere effect of maple leaves falling from the sky. For example, when the preset pattern shape is snowflake shape, the LED chip can adopt white light source, is projected to the projection surface through the light path system of the application, and then is driven to move by the rotary drive module, so as to create the atmosphere effect of snowflakes falling from the sky. For example, when the preset pattern shape is star shape, the LED chip can adopt white light source, is projected to the projection surface through the light path system of the application, and then is driven to move by the rotary drive module, so as to create the atmosphere effect of starlight flowing, star river shining and stars falling. For example, when the preset pattern shape is cloud shape, the LED chip can adopt white light source, is projected to the projection surface through the light path system of the application, and then is driven to move by the rotary drive module, so as to create the atmosphere effect of wind and cloud surging. For example, when the preset pattern shape is swastika shape, the LED chip can adopt gold light source, is projected to the projection surface through the light path system of the application, and then is driven to move by the rotary drive module, so as to create the atmosphere effect of Buddha light shining, which is especially suitable for application in temples.

[0051] As an implementation, the dynamic multi-spot projection optical system based on LED light source satisfies the following formula: 0.6× delta <(X×360° / m)< delta ; Wherein, X is the angular magnification of the whole optical system of the dynamic multi-spot projection optical system based on LED light source, delta is the angular diameter of a single projection unit on the projection surface (i.e. the angular diameter of a spot cluster formed by adjacent sub-beams on the projection surface, and the calculation formula is: δ = 2 × arctan(d / 2D), wherein d is the physical size of the spot cluster, and D is the projection distance). The angular magnification of the optical system is related to the focal length of the condenser lens, the curvature of the concave mirror, the image distance, the taper of the reflector cover, etc. The value range of the angular magnification X is 0.1-0.3, the value range of m is 20-40, and the value range of the δ is 1.5°-3.0°. The application makes part of the projection units intersect with each other, so that the projection effect is more natural in vision.

[0052] In this invention, the light emitted from the LED light source is patterned into a beam by a grating sheet. A conical reflector splits and reflects the beam into multiple sub-beams, which are then guided by an optical mirror assembly to a condenser lens. The biconvex aspherical condenser lens of this invention, through a specific optical design, effectively corrects system aberrations, ensuring clear imaging of all sub-beams. Finally, a concave mirror reflects the imaging beam onto the target surface, forming multiple uniform and clear dynamic patterned light spots. This invention, using a low-cost, laser-free, and safe LED solution, achieves complex dynamic light and shadow effects comparable to or even surpassing laser projection through innovative optical design, while maintaining consistent image clarity within a projection distance range of 2-15 meters. Example 1

[0053] The LED light source uses a white LED chip with a rated power of 6W and a color temperature of 6500K to emit incoherent light, fundamentally avoiding the problem of laser speckle.

[0054] The grating sheet is made of stainless steel sheet through photolithography. It is 0.1mm thick and 0.2mm apart from the LED light source chip. The light-transmitting area with snowflake pattern is etched on it, and the light-transmitting hole size is 1.8mm×1.8mm.

[0055] The reflector consists of eight planar reflectors (A) joined together to form a conical structure with a 45° cone angle. The mirrors are vacuum-plated with aluminum, achieving a reflectivity greater than 95%. This reflector is used to divide and reflect the patterned beam emitted by the LED light source into eight identical sub-beams. The optical reflection assembly comprises a first planar reflector and a second planar reflector, each with a surface size of 36mm × 36mm and a silver-plated finish. This assembly is used to redirect the optical path twice, reducing the total optical path length of the system from 350mm to 200mm.

[0056] The condenser lens is manufactured using optical-grade PMMA material through injection molding. Its optical parameters are as follows: focal length 162.99mm, front surface radius of curvature 26180mm, rear surface radius of curvature 80.214mm, front surface conicity k=37.527, rear surface conicity k=-0.9545, and center thickness 5.1325mm.

[0057] Aberration test data: like Figure 6 As shown in the simulation results using LightTools optical software, this lens exhibits excellent aberration performance at different wavelengths: 486nm wavelength: maximum spherical aberration 0.09mm, field curvature 0.4% 587nm wavelength: maximum spherical aberration 0.08mm, field curvature 0.3%. 656nm wavelength: maximum spherical aberration 0.10mm, field curvature 0.45% Aberrations at all wavelengths meet the requirements for clear imaging of multiple light spots.

[0058] Supplemental wavelength test data: 450nm wavelength: maximum spherical aberration 0.11mm, field curvature 0.48% 520nm wavelength: maximum spherical aberration 0.085mm, field curvature 0.35% 620nm wavelength: maximum spherical aberration 0.095mm, field curvature 0.41% The test results show that the lens maintains excellent aberration correction performance in the full visible light wavelength band of 450-656nm.

[0059] The concave mirror is composed of 36 plane mirrors B spliced into a concave structure, each plane mirror has a size of 5mm*5mm, and the installation angle is accurately calculated to reflect the imaged light beam to the final projection surface.

[0060] The rotating drive module adopts a 28BYJ-48 stepping motor, the rotating speed is set to 1rpm-5rpm, the concave mirror is driven to rotate, and all the pattern light spots on the projection surface generate a flowing and rotating dynamic effect.

[0061] The light emitted by the LED light source forms a pattern light after the grating sheet, and is divided into 8 sub-beams by the reflector cover. After being turned by the optical reflection assembly, the sub-beams are incident to the biconvex aspherical condenser lens, and the lens clearly images all the sub-beams. Finally, the imaged light beam is reflected to the target wall surface by the rotating concave mirror, and 288 (8*36) uniform, clear and dynamic snowflake pattern light spots are formed.

[0062] In the embodiment, m=36, and the angular magnification X=0.18. Under a projection distance of 3m, δ=2.5°. Substituting into the calculation, (0.18*360° / 36)=1.8°, which satisfies 0.6*2.5°=1.5°<1.8°<2.5°.

[0063] The present application ensures that the adjacent projection units projected by adjacent plane mirrors B on the concave mirror have a partial overlapping area on the projection surface. When (X*360° / m) is too large than δ, the light spot interval is too large, and the distribution is sparse; when (X*360° / m) is too small than δ, the light spot overlaps seriously, and the pattern is blurred. The present application determines the ratio range through a large number of experiments and optical simulation, so that the light spots form a continuous, uniform and non-obvious interval "sky" effect in vision.

[0064] As shown in Figure 7 the actual test, the MTF of the optical system of the embodiment of the present application under different projection distances is as follows: 2m projection distance: MTF=0.48 under 20lp / mm; 8m projection distance: MTF = 0.45 at 20 lp / mm; 15m projection distance: MTF = 0.42 at 20 lp / mm.

[0065] The MTF values at all test distances are greater than 0.4, meeting the clear imaging requirements, and the change amplitude is less than 10%, proving that the system has stable imaging performance in the range of 2-15 meters.

[0066] The projection distance test data are as follows: 4m projection distance: MTF = 0.47 at 20 lp / mm; 6m projection distance: MTF = 0.46 at 20 lp / mm; 10m projection distance: MTF = 0.44 at 20 lp / mm; 12m projection distance: MTF = 0.43 at 20 lp / mm.

[0067] The test results show that the optical system of the embodiment of the present application maintains excellent imaging performance in the full range of 2-15 meters. Embodiment 2

[0068] Embodiment 2 is basically the same as Embodiment 1, except that the grating sheet is provided with maple leaf-shaped light transmission areas; the light shield is spliced by 12 plane mirrors; and the concave mirror is spliced by 24 plane mirrors. The optical system parameters of the embodiment of the present application are adjusted to satisfy the relationship 0.6δ < (X × 360° / m) < δ, wherein X = 0.15, m = 24, and δ = 2.2° (at a 3m projection distance), and (X × 360° / m) = (0.15 × 360° / 24) = 2.25°, which satisfies 0.6 × 2.2° = 1.32° < 2.25° < 2.2°.

[0069] Multi-wavelength aberration test: 486nm wavelength: maximum spherical aberration 0.10mm, field curvature 0.42% 587nm wavelength: maximum spherical aberration 0.09mm, field curvature 0.38% 656nm wavelength: maximum spherical aberration 0.11mm, field curvature 0.47% The actual measurement shows that the embodiment of the present application can form 288 clear maple leaf pattern light spots in the projection distance range of 2-15 meters, the light spot uniformity is greater than 90%, and the edge definition is significantly better than the comparative laser scheme.

[0070] The present application is suitable for landscape lighting, atmosphere lighting, commercial display, education projection, stage lighting and other application scenarios.

[0071] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A dynamic multi-spot projection optical system based on an LED light source, characterized in that, The device includes an LED light source, a reflector, a grating sheet, a condenser lens, a concave mirror, and an optical reflection assembly. The LED light source is located at the bottom of the reflector, and the grating sheet is located above the LED light source. The grating sheet has a light-transmitting area with a preset pattern shape. The reflector is composed of several planar mirrors A, which are connected in sequence to form a conical reflective surface. The concave mirror is composed of several planar mirrors B. The optical reflection assembly reflects the light reflected from the reflector to the condenser lens, which focuses the light before reflecting it out by the concave mirror.

2. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, It also includes a grating turntable, which has several grating plates at the center of the ring turntable. The grating plates above the LED light source are switched by rotating the grating turntable.

3. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, The optical reflection assembly consists of a plane mirror A and a plane mirror B. The plane mirror A is positioned above the reflector, and the plane mirror B is positioned in front of the plane mirror A. The plane mirror A reflects the light reflected from the reflector to the plane mirror B, and then the plane mirror B reflects the light to the condenser lens.

4. The dynamic multi-spot projection optical system based on an LED light source as described in claim 3, characterized in that, A light-blocking plate is provided between the condenser lens and the reflector.

5. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, The condenser lens adopts a biconvex aspherical structure, where both its front and rear surfaces are even-order aspherical surfaces, and satisfy the following conditions: The focal length is 162.99mm±5%, the radius of curvature of the front surface is 26180mm±5%, the radius of curvature of the rear surface is 80.214mm±5%, the conicity of the front surface is k=37.527±5%, the conicity of the rear surface is k=-0.9545±5%, and the center thickness is 5.1325mm±5%.

6. The dynamic multi-spot projection optical system based on an LED light source as described in claim 5, characterized in that, The refractive index of the condenser lens is 1.493±5%, and the Abbe number is 57.2±5%.

7. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, The preset pattern shape is one or more of the following: maple leaf, snowflake, star, cloud, and swastika.

8. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, It also includes a rotary drive module, with a concave reflector correspondingly mounted on the output shaft of the rotary drive module.

9. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, A concave mirror is a parabolic mirror.

10. The dynamic multi-spot projection optical system based on an LED light source as described in claim 1, characterized in that, The reflector includes n planar mirrors A, and the concave reflector includes m planar mirrors B. The n+1 light spots reflected by the optical reflection components in a preset pattern shape are used as a projection unit. The dynamic multi-spot projection optical system based on an LED light source satisfies the following equation: 0.6× δ <(X×360° / m)< δ ; Where X represents the angular magnification of the entire optical system of the dynamic multi-spot projection optical system based on LED light source. δ The angular diameter of a single projection unit on the projection plane.

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