Projection optical system
By designing reasonable power distribution and component layout in the projection optical system, the problem of excessive volume of ultra-short focal projection lenses is solved, and miniaturization and high-resolution imaging are achieved.
Patent Information
- Application Number
- CN202421634202.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-07-10
AI Technical Summary
Existing ultra-short focal projection lenses are too large, making the device bulky and difficult to carry.
A projection optical system is designed, including a reflector, a movable lens group, a fixed lens group and a light emitting chip, which reduces the size of the lens by reasonably allocating the light power while maintaining high-resolution imaging.
The projection optical system is miniaturized, while ensuring high-resolution imaging, solving the problem of excessive volume.
Smart Images
Figure CN222965564U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of projection optical devices, and particularly relates to a projection optical system. Background Art
[0002] In recent years, with the development of projection technology, ultra-short throw projection has been widely used in the home field. Because it can project a large screen at a short distance, it has the trend of gradually replacing traditional TVs.
[0003] At present, the design of ultra-short throw projection lenses on the market mainly adopts the structure of a refractive lens group plus a reflective lens group. In order to achieve high resolution, a large number of spherical lenses are often used, which further leads to an increase in volume. Summary of the Utility Model
[0004] The main purpose of the utility model is to propose a projection optical system, aiming to solve the problem of the too large volume of existing ultra-short throw projection lenses.
[0005] To achieve the above object, the projection optical system proposed by the utility model includes a reflecting mirror, a movable lens group, a fixed lens group, and a light-emitting chip arranged in sequence along the optical axis direction. The reflecting mirror is used to be arranged close to the projection surface. The movable lens group is movably arranged along the extension direction of the optical axis. The optical power of the reflecting mirror satisfies 0.08 ≤ |φ 300 | ≤ 0.011, the optical power of the movable lens group satisfies 0.005 ≤ |φ 200 | ≤ 0.01, and the optical power of the fixed component satisfies 0.04 ≤ |φ 100 | ≤ 0.05.
[0006] In an embodiment, the ratio of the optical power of the fixed lens group to the optical power of the movable lens group satisfies 5 ≤ |φ 100 / φ 200 | ≤ 8.
[0007] In an embodiment, the fixed lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence along the optical axis direction. The first lens is arranged close to the light-emitting chip. The optical powers of the first lens, the third lens, the fifth lens, the sixth lens, and the eighth lens are positive, and the optical powers of the second lens and the fourth lens are negative;
[0008] Among them, the first lens is a glass aspherical lens.
[0009] In an embodiment, the third lens, the fourth lens, and the fifth lens are connected by gluing;
[0010] The sixth lens, the seventh lens, and the eighth lens are connected by gluing.
[0011] In one embodiment, the optical power of the first lens is φ 1 , 0.05 ≤ |φ 1 | ≤ 0.07;
[0012] The optical power of the second lens is φ 2 , 0.03 ≤ |φ 2 | ≤ 0.05;
[0013] The optical powers of the third lens, the fourth lens, and the fifth lens are φ 345 , 0.006 ≤ |φ 345 | ≤ 0.009;
[0014] The optical powers of the sixth lens, the seventh lens, and the eighth lens are φ 678 , 0.03 ≤ |φ 678 | ≤ 0.05.
[0015] In one embodiment, the movable lens group includes a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged in sequence along the optical axis. The ninth lens is disposed close to the light-emitting chip. The optical powers of the ninth lens, the eleventh lens, and the fourteenth lens are positive, and the optical powers of the tenth lens, the twelfth lens, and the thirteenth lens are negative;
[0016] Among them, the tenth lens, the thirteenth lens, and the fourteenth lens are plastic aspherical lenses.
[0017] In one embodiment, the optical power of the ninth lens is φ 9 , 0.01 ≤ |φ 9 | ≤ 0.03;
[0018] The optical power of the tenth lens is φ 10 , 0.008 ≤ |φ 10 | ≤ 0.015;
[0019] The optical power of the eleventh lens is φ 11 , 0.02 ≤ |φ 11 | ≤ 0.04;
[0020] The optical power of the twelfth lens is φ 12 , 0.03 ≤ |φ 12 | ≤ 0.05;
[0021] The optical power of the thirteenth lens is φ 13 , 0.01 ≤ |φ 13|≤0.04;
[0022] The optical power of the fourteenth lens is φ 14 , 0.005 ≤ |φ 14 |≤0.02.
[0023] In an embodiment, the optical powers of the tenth lens, the thirteenth lens, and the fourteenth lens satisfy -0.03 < φ 10 +φ 13 +φ 14 < -0.01.
[0024] In an embodiment, the fixed lens group includes a first lens;
[0025] The moving lens group includes a fourteenth lens. The center distance between the fourteenth lens and the mirror is T 1， The center distance between the fourteenth lens and the first lens is T 2 , 1.2 ≤ T 2 / T 1 ≤ 1.5.
[0026] In an embodiment, the projection optical system further includes a protective glass, a galvanometer, and an equivalent prism arranged in sequence along the optical axis direction. The protective glass is disposed close to the light-emitting chip.
[0027] In the technical solution of the present utility model, the light emitted by the light-emitting chip is sequentially incident into the fixed lens group and the movable lens group to irradiate the mirror for primary imaging. Then, the mirror can reflect the light of the primary imaging to the projection plane to form secondary imaging. With such a setting, by adopting a combined structure of the fixed lens group and the movable lens group and other refractive lens groups and the mirror, high-resolution imaging can be achieved. At the same time, since the optical power of the mirror satisfies 0.08 ≤ |φ 300 |≤ 0.011, the optical power of the movable lens group satisfies 0.005 ≤ |φ 200 |≤ 0.01, the optical power of the fixed lens group satisfies 0.04 ≤ |φ 100 |≤ 0.05, and the optical power of the fixed lens group is positive while the optical power of the movable lens group is negative. Thus, through a reasonable distribution of the system optical power, the volume of the lens can be greatly reduced, ensuring the miniaturization of the projection optical system without affecting its own resolution. Description of the Drawings
[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.
[0029] Figure 1 Schematic structural diagram of an embodiment of the projection optical system provided by the present invention;
[0030] Figure 2 For Figure 1 Schematic optical path diagram of the projection optical system in
[0031] Figure 3 For Figure 1 Schematic performance diagram of the projection optical system in
[0032] Figure 4 For Figure 1 Schematic chromatic aberration diagram of the projection optical system in
[0033] Explanation of the reference numerals in the drawings:
[0034] 100, projection optical system; 1, movable lens group; 11, first lens; 12, second lens; 13, third lens; 14, fourth lens; 15, fifth lens; 16, sixth lens; 17, seventh lens; 18, eighth lens; 2, fixed lens group; 21, ninth lens; 22, tenth lens; 23, eleventh lens; 24, twelfth lens; 25, thirteenth lens; 26, fourteenth lens; 3, mirror; 4, light-emitting chip; 5, protective glass; 6, galvanometer; 7, equivalent prism.
[0035] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the drawings. Specific embodiments
[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.
[0037] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain specific posture. If this specific posture changes, then the directional indications will also change accordingly.
[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0039] The present utility model provides a projection optical system, aiming to solve the problem that the existing ultra-short focal length projection lens is too large in volume.
[0040] Please refer to Figure 1-2 , in an embodiment of the present utility model, the projection optical system 100 includes a reflecting mirror 3, a movable lens group 1, a fixed lens group 2, and a light-emitting chip 4 arranged in sequence along the optical axis direction. The reflecting mirror 3 is used to be arranged close to the projection surface. The movable lens group 1 is arranged movably along the extension direction of the optical axis. The optical power of the reflecting mirror 3 satisfies 0.08 ≤ |φ 300 | ≤ 0.011, the optical power of the movable lens group 1 satisfies 0.005 ≤ |φ 200 | ≤ 0.01, the optical power of the fixed lens group 2 satisfies 0.04 ≤ |φ 100 | ≤ 0.05, the optical power of the fixed lens group 2 is positive, and the optical power of the movable lens group 1 is negative.
[0041] In the technical solution of the present utility model, the light emitted by the light-emitting chip 4 is sequentially incident into the fixed lens group 2 and the movable lens group 1 to irradiate onto the reflecting mirror 3 for primary imaging. Then, the reflecting mirror 3 can reflect the light of the primary imaging to the projection surface to form a secondary imaging. With such a setting, by adopting the combined structure of the refractive lens groups such as the fixed lens group 2 and the movable lens group 1 and the reflecting mirror 3, high-resolution imaging can be achieved. At the same time, since the optical power of the reflecting mirror 3 satisfies 0.08 ≤ |φ300 |≤0.011, and the optical power of the movable lens group 1 satisfies 0.005≤|φ 200 |≤0.01, and the optical power of the fixed lens group 2 satisfies 0.04≤|φ 100 |≤0.05, and the optical power of the fixed lens group 2 is positive, and the optical power of the movable lens group 1 is negative. In this way, through the reasonable distribution of the optical power of the system, the volume of the lens can be greatly reduced, ensuring that the projection optical system 100 is miniaturized without affecting its own resolution.
[0042] It can be understood that the present invention does not limit the specific numerical values of the optical power of the fixed lens group 2, the movable lens group 1, and the reflector 3, as long as the optical power of the fixed lens group 2 satisfies 0.04≤|φ 100 |≤0.05, the optical power of the movable lens group 1 satisfies 0.005≤|φ 200 |≤0.01, and the optical power of the reflector 3 satisfies 0.08≤|φ 300 |≤0.011. The specific numerical values can be selected according to requirements, and the present invention does not limit this.
[0043] In addition, to further ensure the resolution of the projection optical system 100, in an embodiment of the present invention, the ratio of the optical power of the fixed lens group 2 and the movable lens group 1 satisfies 5≤|φ 100 / φ 200 |≤8. With such a setting, while ensuring the miniaturization ability of the projection optical system 100, the high-resolution imaging of the projection optical system 100 can be further ensured.
[0044] It should be noted that the present invention does not limit the number of lenses in the fixed lens group 2. In an embodiment of the present invention, the fixed lens group 2 includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a sixth lens 16, a seventh lens 17, and an eighth lens 18 arranged in sequence along the optical axis. The first lens 11 is arranged close to the light-emitting chip 4. The optical powers of the first lens 11, the third lens 13, the fifth lens 15, the sixth lens 16, and the eighth lens 18 are positive, the optical powers of the second lens 12 and the fourth lens 14 are negative, and the first lens 11 is a glass aspherical lens.
[0045] It can be understood that the aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using the aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality of the lens. At the same time, since the first lens 11 is disposed close to the light-emitting chip 4, therefore, using a glass aspherical lens can also enable the first lens 11 to have good resistance to thermal deformation, reduce the influence of the heat emitted by the light-emitting chip 4 during operation on the first lens 11, and further reduce the influence of temperature on the optical performance of the projection optical system 100, so as to maintain the high resolution of the projection optical system 100 for a long time.
[0046] At the same time, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, and the sixth lens 16 are all set as plastic lenses. In this way, the manufacturing cost of the projection optical system 100 can be reduced.
[0047] Furthermore, in order to reduce the chromatic aberration of the projection image of the projection optical system 100, in an embodiment of the present invention, the third lens 13, the fourth lens 14, and the fifth lens 15 are connected by gluing. With this setting, the air layer between the third lens 13, the fourth lens 14, and the fifth lens 15 can be removed, so that the projection light will not have an angular deviation between the third lens 13, the fourth lens 14, and the fifth lens 15, in order to correct the chromatic aberration of the projection image of the projection optical system 100.
[0048] In another embodiment of the present invention, the sixth lens 16, the seventh lens 17, and the eighth lens 18 are connected by gluing. With this setting, the air layer between the sixth lens 16, the seventh lens 17, and the eighth lens 18 can also be removed to correct the chromatic aberration of the projection image of the projection optical system 100.
[0049] In summary, in this embodiment, the third lens 13, the fourth lens 14, and the fifth lens 15 are connected by gluing, and the sixth lens 16, the seventh lens 17, and the eighth lens 18 are also connected by gluing. In this way, by setting multiple triplet lens structures, the chromatic aberration of the projection image of the projection optical system 100 can be corrected together, so as to achieve the purpose of greatly reducing the chromatic aberration of the projection optical system 100.
[0050] In this embodiment, the optical power of the first lens 11 is φ 1 , 0.05 ≤ |φ 1 | ≤ 0.07, and the optical power of the second lens 12 is φ 2 , 0.03 ≤ |φ 2|≤0.05, the optical powers of the third lens 13, the fourth lens 14, and the fifth lens 15 are φ 345 , 0.006 ≤ |φ 345 |≤0.009, the optical powers of the sixth lens 16, the seventh lens 17, and the eighth lens 18 are φ 678 , 0.03 ≤ |φ 678 |≤0.05.
[0051] It can be understood that the present utility model does not limit the optical power φ of the first lens 11 1 , the optical power φ of the second lens 12 2 , the total optical power of the third lens 13, the fourth lens 14, and the fifth lens 15, and the sixth lens 16φ 345 , the total optical power of the seventh lens 17 and the eighth lens 18, φ 678 , and only needs to ensure that the optical power φ of the first lens 11 1 , the optical power φ of the second lens 12 2 , the total optical power of the third lens 13, the fourth lens 14, and the fifth lens 15, and the sixth lens 16φ 345 , the total optical power of the seventh lens 17 and the eighth lens 18, φ 678 are within the corresponding ranges.
[0052] In addition, the present utility model does not limit the specific number of lenses in the moving lens group either. In an embodiment of the present utility model, the moving lens group includes a ninth lens 21, a tenth lens 22, an eleventh lens 23, a twelfth lens 24, a thirteenth lens 25, and a fourteenth lens 26 arranged in sequence along the optical axis direction. The ninth lens 21 is disposed close to the light-emitting chip 4. The optical powers of the ninth lens 21, the eleventh lens 23, and the fourteenth lens 26 are positive, and the optical powers of the tenth lens 22, the twelfth lens 24, and the thirteenth lens 25 are negative. The tenth lens 22, the thirteenth lens 25, and the fourteenth lens 26 are plastic aspherical lenses.
[0053] It can be understood that the aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using the aspherical lens, the aberration that appears during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. At the same time, since the tenth lens 22, the thirteenth lens 25, and the fourteenth lens 26 are all located on the side of the fixed lens group 2 away from the light-emitting chip 4, therefore, the tenth lens 22, the thirteenth lens 25, and the fourteenth lens 26 are all spaced relatively far from the light-emitting chip 4. Using a plastic aspherical lens will not only not be affected by the heat emitted by the light-emitting chip 4, but also can reduce the manufacturing cost of the projection optical system 100. To reduce the manufacturing cost of the projection optical system 100, at the same time, through the reasonable combination of multiple plastic lenses with positive and negative optical powers in the present invention, the projection optical system 100 can output at a brightness of 2500 lm and ensure that there is no defocus phenomenon when the projection optical system 100 outputs.
[0054] Further, the optical power of the ninth lens 21 is φ 9 , 0.01 ≤ |φ 9 | ≤ 0.03, the optical power of the tenth lens 22 is φ 10 , 0.008 ≤ |φ 10 | ≤ 0.015, the optical power of the eleventh lens 23 is φ 11 , 0.02 ≤ |φ 11 | ≤ 0.04, the optical power of the twelfth lens 24 is φ 12 , 0.03 ≤ |φ 12 | ≤ 0.05, the optical power of the thirteenth lens 25 is φ 13 , 0.01 ≤ |φ 13 | ≤ 0.04, the optical power of the fourteenth lens 26 is φ 14 , 0.005 ≤ |φ 14 | ≤ 0.02.
[0055] It can be understood that the present invention does not limit the specific values of the optical power φ 9 of the ninth lens 21, the optical power φ 10 of the tenth lens 22, the optical power φ 11 of the eleventh lens 23, the optical power φ 12 of the twelfth lens 24, the optical power φ 13 of the thirteenth lens 25, and the optical power φ 14 of the fourteenth lens 26. It only needs to ensure that the optical power φ 9 of the ninth lens 21, the optical power φ 10 of the tenth lens 22, the optical power φ11 The optical power φ of the twelfth lens 24 12 The optical power φ of the thirteenth lens 25 13 And the optical power φ of the fourteenth lens 26 14 can take values within the corresponding ranges.
[0056] Furthermore, to further ensure the high resolution of the projection optical system 100. In an embodiment of the present invention, the optical powers of the tenth lens 22, the thirteenth lens 25, and the fourteenth lens 26 satisfy -0.03 < φ 10 +φ 13 +φ 14 < -0.01. With such a setting, while ensuring the miniaturization ability of the projection optical system 100, it can further ensure high-resolution imaging of the projection optical system 100.
[0057] Specifically, to ensure the miniaturization ability of the projection optical system 100, in an embodiment of the present invention, the center distance between the fourteenth lens 26 and the mirror 3 is T 1 , and the center distance between the fourteenth lens 26 and the first lens 11 is T 2 , 1.2 ≤ T 2 / T 1 ≤ 1.5. With such a setting, the distance between the first lens 11 and the mirror 3 can be restricted, that is, the length of the projection optical system 100 in the optical axis direction can be restricted, thereby ensuring the miniaturization of the projection optical system 100.
[0058] In addition, it should be noted that the projection optical system 100 further includes a protective glass 5, a galvanometer 6, and an equivalent prism 7 arranged in sequence along the optical axis direction, and the protective glass 5 is arranged close to the light-emitting chip 4. With such a setting, the light emitted by the light-emitting chip 4 passes through the protective glass 5, the galvanometer 6, and the equivalent prism 7 in sequence, and then enters the fixed lens group 2 for light correction. At the same time, since the protective glass 5 is arranged close to the light-emitting chip 4, it can provide effective protection for the light-emitting chip 4.
[0059] The present invention provides a specific embodiment of the projection optical system 100. In this embodiment, the projection ratio of the projection optical system 100 is 0.22, the light-emitting chip 4 includes a DMD chip with a diameter of 0.47 inches, and the size of the chip pixel is 5.4 microns, the chromatic aberration is less than 0.3 Pixel, and the distance from the DMD chip to the center of the mirror 3 is less than 166 mm. Thus, in this embodiment, the basic parameter tables of the surface shape, radius, thickness, optical material, and aperture of each lens of the projection optical system are shown in Table 1:
[0060] Table 1
[0061]
[0062]
[0063] In addition, in this embodiment, the aspheric coefficients of the aspherical lens in the projection optical system 100 include: the conic coefficient k of this surface, the fourth-order aspheric coefficient A, the sixth-order aspheric coefficient B, the eighth-order aspheric coefficient C, the tenth-order aspheric coefficient D, the twelfth-order aspheric coefficient E, the fourteenth-order aspheric coefficient F, and the sixteenth-order aspheric coefficient G, as shown in Table 2 below:
[0064] Table 2
[0065]
[0066]
[0067] Figure 3 This is a schematic diagram of the performance of the projection optical system 100 in this embodiment, Figure 4 This is a schematic diagram of the chromatic aberration of the projection optical system 100 in this embodiment.
[0068] It should be noted that Table 2 shows a set of design values of the aspheric coefficients of the lenses in the projection optical system 100 in this embodiment. The specific numerical values of the aspheric coefficient design values can be adjusted according to the requirements of the product, and the present invention does not limit this.
[0069] The above description is only an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.
Claims
1. A projection optical system, characterized in that: The projection optical system comprises a reflector, a movable lens group, a fixed lens group and a light emitting chip arranged in sequence along the optical axis direction, the reflector is arranged close to the projection surface, the movable lens group is movably arranged along the extension direction of the optical axis, and the optical focal length of the reflector satisfies 0.08≤|φ 300 |≤0.011, the optical power of the movable lens group satisfies 0.005≤|φ 200 |≤0.01, the focal length of the fixed lens group satisfies 0.04≤|φ 100 |≤0.
05.
2. The projection optical system according to claim 1, characterized in that: The ratio of the optical power of the fixed lens group to the optical power of the movable lens group satisfies 5≤|φ 100 / φ 200 |≤8.
3. The projection optical system according to claim 1, wherein: The fixed lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence along the optical axis direction, the first lens is arranged close to the light emitting chip, the first lens, the third lens, the fifth lens, the sixth lens and the eighth lens have positive optical focal lengths, and the second lens and the fourth lens have negative optical focal lengths; Wherein, the first lens is a glass aspherical lens.
4. The projection optical system according to claim 3, characterized in that: The third lens, the fourth lens and the fifth lens are connected by gluing; The sixth lens, the seventh lens and the eighth lens are connected by gluing.
5. The projection optical system according to claim 3, characterized in that: The optical power of the first lens is φ1, 0.05≤|φ1|≤0.07; The optical power of the second lens is φ2, 0.03≤|φ2|≤0.05; The optical power of the third lens, the fourth lens and the fifth lens is φ 345 , 0.006≤|φ 345 |≤0.009; The optical power of the sixth lens, the seventh lens and the eighth lens is φ 678 , 0.03≤|φ 678 |≤0.
05.
6. The projection optical system according to claim 1, wherein: The movable lens group comprises a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens arranged in sequence along the optical axis direction, the ninth lens is arranged close to the light emitting chip, the ninth lens, the eleventh lens and the fourteenth lens have positive focal powers, and the tenth lens, the twelfth lens and the thirteenth lens have negative focal powers; Wherein, the tenth lens, the thirteenth lens and the fourteenth lens are plastic aspherical lenses.
7. The projection optical system according to claim 6, characterized in that: The optical power of the ninth lens is φ9, 0.01≤|φ9|≤0.03; The optical power of the tenth lens is φ 10 , 0.008≤|φ 10 |≤0.015; The focal power of the eleventh lens is φ 11 , 0.02≤|φ 11 |≤0.04; The focal length of the twelfth lens is φ 12 , 0.03≤|φ 12 |≤0.05; The focal power of the thirteenth lens is φ 13 ,0.01≤|φ 13 |≤0.04; The focal power of the fourteenth lens is φ 14 , 0.005≤|φ 14 |≤0.
02.
8. The projection optical system according to claim 7, characterized in that: The optical power of the tenth lens, the thirteenth lens and the fourteenth lens satisfies -0.03<φ 10 +φ 13 +φ 14 <-0.
01.
9. The projection optical system according to claim 1, characterized in that: The fixed lens group includes a first lens; The movable lens group includes a fourteenth lens, the center distance between the fourteenth lens and the reflector is T1, the center distance between the fourteenth lens and the first lens is T2, and 1.2≤T2 / T1≤1.
5.
10. The projection optical system according to claim 1, wherein: The projection optical system further comprises a protective glass, a galvanometer and an equivalent prism which are sequentially arranged along the optical axis direction, and the protective glass is arranged close to the light emitting chip.