3D printing lens and projection equipment

Abstract

The utility model discloses a 3D printing lens and a projection device, comprising a front group lens group, a diaphragm and a rear group lens group which are sequentially arranged in a direction from an object plane to an image plane, and the focal length of the lens is 10mlt; flt; the focal length of the front lens group is-100mm, and the focal length of the rear lens group is-100mm; f front lt; the focal length of the rear lens group is-50mm, and the focal length of the rear lens group is 15mlt; f rear lt; 25 mm; the lens is highly matched with a 0.47-inch DMD chip, the offset rate of the lens can reach 0%, optical distortion is small, imaging is good, and the projection ratio of the lens is larger than 0.5 and smaller than 1.35; the device has a large defocus range and can adapt to an unstable lighting environment; the imaging picture brightness is uniform, the edge loss light energy is less, and the illumination light utilization rate is high.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging, in particular to a 3D printing lens and a projection device based on the lens. Background Art

[0002] 3D printing, also known as additive manufacturing, is a new manufacturing technology that takes a digital model as the basis and stacks materials layer by layer to manufacture physical objects. It is a technology that uses powdered metals or plastics and other bondable materials based on digital model files and constructs objects by printing layer by layer. Compared with traditional subtractive manufacturing methods (processing methods that remove materials with tools), additive manufacturing has many advantages: 1. Shorten the production and manufacturing time and improve efficiency; 2. Improve the utilization efficiency of raw materials; 3. Realize complex structures to improve product performance. At present, additive manufacturing has formed a technical system with relatively mature basic technologies and continuous innovation of new technologies, and there are also endless innovations in the material part. With the development of society, 3D printing optical projectors using DLP (Digital Light Procession) projection technology have emerged.

[0003] At present, 3D printing devices based on DLP technology have now appeared in desktop and industrial-grade products. Their desktop applications are mainly concentrated in fields such as dentistry, jewelry, cultural and creative products, etc. Based on the unique advantages of DLP technology, the printed parts have the advantages of high precision and fast printing speed, and are more suitable for fields with small size and small batch requirements, such as dentistry, small part batch production, mold manufacturing, etc. Nowadays, with the increasing demand for high-resolution light machines, there is an urgent need to develop high-resolution lenses with a high degree of matching with DLP technology. Summary of the Utility Model

[0004] A technical problem to be solved by the utility model is to provide a 3D printing lens that can be well matched with DLP technology.

[0005] To solve the above technical problem, the technical solution of the utility model is: a 3D printing lens, including a front group lens, a diaphragm, and a rear group lens sequentially arranged in the direction from the object surface to the image surface, the focal length of the lens is 10mm < f < 17mm, the focal length of the front group lens is -100mm < f 前 < -50mm, and the focal length of the rear group lens is 15mm < f 后 < 25mm.

[0006] Optionally, the front group lens includes a first lens, a second lens, a third lens, and a fourth lens sequentially arranged in the direction from the object surface to the diaphragm, the first lens and the fourth lens are positive focal length lenses, and the second lens and the third lens are negative focal length lenses.

[0007] Optionally, the rear lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence from the aperture to the image plane direction, the fifth lens, the eighth lens, the ninth lens and the tenth lens are lenses with positive optical power, and the sixth lens and the seventh lens are lenses with negative optical power.

[0008] Optionally, the fourth lens is a movable focusing lens, and the projection distance of the lens is 150mm±25mm.

[0009] Optionally, the focal length of the seventh lens is -16mm <f 7 <-5mm or -30mm <f 7 <-17mm;

[0010] And / or, the focal length of the ninth lens is 10 mm <f 9 <51mm.

[0011] Optionally, a ratio of an air gap between the third lens and the fourth lens to a total optical length of the lens is 0.02≤Air3 / total length<0.15.

[0012] Optionally, the ratio of the air gap between the fourth lens and the aperture to the total optical length of the lens is 0.02≤Air4 / total length<0.15; the ratio of the air gap between the aperture and the fifth lens to the total optical length of the lens is 0.02≤Air aperture / total length<0.1.

[0013] Optionally, the lens is used for a 0.47-inch DMD chip, and the projection ratio is 0.5<1.35.

[0014] Optionally, the lens is suitable for a short-wave monochromatic light source in the range of 400nm±5nm.

[0015] Another technical problem to be solved by the present invention is to provide a projection device based on the above-mentioned 3D printing lens.

[0016] In order to solve the above technical problems, the technical solution of the utility model is: a projection device, including the lens mentioned above, wherein the lens, a galvanometer, an equivalent turning prism and an image source are arranged in sequence against the direction of the light path.

[0017] Optionally, the image source includes a spatial light modulator and a projection light source.

[0018] The beneficial effects of this application are:

[0019] A 3D printing lens described in this application includes a front lens group, a diaphragm, and a rear lens group sequentially arranged in the direction from the object plane to the image plane. The focal length of the lens is 10mm < f < 17mm, the focal length of the front lens group is -100mm < f 前 < -50mm, and the focal length of the rear lens group is 15mm < f 后 < 25mm; This lens has a high matching degree with a 0.47-inch DMD chip, the lens offset rate can reach 0%, the optical distortion is small, the imaging is good, and the projection ratio of the lens can be achieved as 0.5 < projection ratio < 1.35; It has a large defocus range and can adapt to an unstable lighting environment; The imaging picture has uniform brightness, less light energy loss at the edge, and high utilization rate of illumination light.

[0020] The projection device described in this application uses the above-mentioned lens, can be matched with a 0.47-inch DMD chip in DLP technology, the lens offset rate can reach 0%, the optical distortion is small, the imaging is good, and the projection quality is high. Brief Description of the Drawings

[0021] The following drawings are only intended to illustrate and explain the present utility model schematically and do not limit the scope of the present utility model. Among them:

[0022] Figure 1 is the schematic structural diagram of the first embodiment of the present utility model;

[0023] Figure 2 is the optical path diagram of the first embodiment of the present utility model;

[0024] Figure 3 is the optical distortion diagram of the first embodiment of the present utility model;

[0025] Figure 4 is the MTF diagram of the first embodiment of the present utility model;

[0026] Figure 5 is the defocus MTF diagram of the first embodiment of the present utility model;

[0027] Figure 6 is the relative illumination diagram of the first embodiment of the present utility model;

[0028] Figure 7 is the defocus MTF diagram after the fourth lens is shifted to the right in the first embodiment of the present utility model;

[0029] Figure 8 is the optical distortion diagram after the fourth lens is shifted to the right in the first embodiment of the present utility model;

[0030] Fig. 9 is the defocus MTF diagram after the fourth lens is shifted to the left in the first embodiment of the present utility model;

[0031] Fig.10It is the optical distortion diagram after the left shift of the fourth lens in the first embodiment of the present utility model;

[0032] Fig.11 It is the optical path diagram of the second embodiment of the present utility model;

[0033] Fig.12 It is the MTF diagram of the second embodiment of the present utility model;

[0034] Fig.13 It is the defocus MTF diagram of the second embodiment of the present utility model;

[0035] Fig.14 It is the optical distortion diagram of the second embodiment of the present utility model;

[0036] Fig.15 It is the relative illumination diagram of the second embodiment of the present utility model;

[0037] In the figure: 1 - the first lens; 2 - the second lens; 3 - the third lens; 4 - the fourth lens; 5 - the fifth lens; 6 - the sixth lens; 7 - the seventh lens; 8 - the eighth lens; 9 - the ninth lens; 10 - the tenth lens; 11 - the diaphragm; 12 - the galvanometer; 13 - the equivalent turning prism; 14 - the spatial light modulator. Specific embodiments

[0038] The present utility model will be further described below in conjunction with the drawings and embodiments. In the following detailed description, only some exemplary embodiments of the present utility model are described by way of illustration. It is understood that those of ordinary skill in the art can recognize that various modifications can be made to the described embodiments without departing from the spirit and scope of the present utility model. Therefore, the drawings and description are illustrative in nature and are not intended to limit the scope of protection of the claims.

[0039] As Figure 1 and Figure 2 shown, a 3D printing lens includes a front lens group, a diaphragm 11, and a rear lens group sequentially arranged in the direction from the object plane to the image plane. The focal length of the lens is 10mm < f < 17mm, the focal length of the front lens group is -100mm < f 前 < -50mm, and the focal length of the rear lens group is 15mm < f 后 < 25mm.

[0040] The front lens group includes a first lens 1, a second lens 2, a third lens 3, and a fourth lens 4 sequentially arranged in the direction from the object plane to the diaphragm 11. The first lens 1 and the fourth lens 4 are positive focal length lenses, and the second lens 2 and the third lens 3 are negative focal length lenses.

[0041] The rear lens group includes a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, and a tenth lens 10 arranged in sequence from the diaphragm 11 to the image plane direction. The fifth lens 5, the eighth lens 8, the ninth lens 9, and the tenth lens 10 are positive focal length lenses, and the sixth lens 6 and the seventh lens 7 are negative focal length lenses. The diaphragm 11 is located between the fourth lens 4 and the fifth lens 5.

[0042] Specifically, the first lens 1 is a positive focal length meniscus lens; the second lens 2 is a negative focal length meniscus lens; the third lens 3 is a negative focal length biconcave lens; the fourth lens 4 is a positive focal length plano-convex lens or biconvex lens; the fifth lens 5 is a positive focal length biconvex lens; the sixth lens 6 is a negative focal length meniscus lens; the seventh lens 7 is a negative focal length biconcave lens or meniscus lens; the eighth lens 8 is a positive focal length meniscus lens; the ninth lens 9 is a positive focal length meniscus lens; the tenth lens 10 is a positive focal length biconvex lens.

[0043] The fourth lens 4 can move for focusing, and the projection distance of the lens is 150mm ± 25mm.

[0044] The first lens 1 to the tenth lens 10 are all spherical lenses. Using all spherical lenses has low tolerance sensitivity, reduces the production and assembly difficulty, and is beneficial to mass-producing high-performance lenses. The first lens 1 to the tenth lens 10 are all glass lenses, with high reliability.

[0045] The focal length of the first lens 1 is 25mm < f 1 < 75mm; the focal length of the second lens 2 is -49mm < f2 < -20mm; the focal length of the third lens 3 is -30mm < f 3 < -21.5mm; the focal length of the fourth lens 4 is 34mm < f 4 < 70mm; the focal length of the fifth lens 5 is 5mm < f 5 < 30mm; the focal length of the sixth lens 6 is -150mm < f 6 < -50mm; the focal length of the seventh lens 7 is -16mm < f 7 < -5mm or -30mm < f 7 < -17mm; the focal length of the eighth lens 8 is 29mm < f 8 < 60mm; the focal length of the ninth lens 9 is 10mm < f 9 < 51mm; the focal length of the tenth lens 10 is 10mm < f 10< 35.9 mm. Based on the above technical features, the optical power distribution of the lens is uniform, resulting in a lower tolerance sensitivity for each lens, avoiding the occurrence of aberrations, improving the lens yield, and facilitating mass production.

[0046] The ratio of the air gap between the third lens 3 and the fourth lens 4 to the optical total length of the lens is 0.02 ≤ Air3 / total length < 0.15. The ratio of the air gap between the fourth lens 4 and the diaphragm 11 to the optical total length of the lens is 0.02 ≤ Air4 / total length < 0.15; the ratio of the air gap between the diaphragm 11 and the fifth lens 5 to the optical total length of the lens is 0.02 ≤ Air diaphragm 11 / total length < 0.1.

[0047] Based on the above distinguishing technical features: ① The beneficial effect of the air interval after the diaphragm 11 (i.e., Air diaphragm 11) under this constraint: ensuring a certain air gap, facilitating the design and assembly of the front and rear groups of the lens, and reducing the difficulty of process assembly;

[0048] ② The beneficial effect of the air gaps before and after the fourth lens 4 under this constraint: ensuring a certain air gap reserved for the fourth lens 4 to enable the front and rear movement of the fourth lens 4 for focusing, and being able to achieve compatibility with a larger range of projection distances.

[0049] In the reverse direction of the optical path, the two curvature radii of the first lens 1 are 10 < R 11 < 40 and 50 < R 12 < 110; the two curvature radii of the second lens 2 are 10 < R 21 < 40 and 5 < R 22 < 15; the two curvature radii of the third lens 3 are -200 < R 31 < -60 and 7 < R 32 < 19; the two curvature radii of the fourth lens 4 are 65 < R 41 and -50 < R 42 < -20; the two curvature radii of the fifth lens 5 are 10 < R 51 < 35 and -35 < R 52 < -15; the two curvature radii of the sixth lens 6 are 10 < R 61 < 35 and 5 < R 62 < 17; the two curvature radii of the seventh lens 7 are -25 < R 71 < -10.1 and -100 < R 72 < 200; the two curvature radii of the eighth lens 8 are -200 < R 81 < -26 and -40 < R 82 < -14; the two curvature radii of the ninth lens 9 are R 91<-50 and -40<R 92 <-10; the two curvature radii of the tenth lens 10 are 29<R 101 <50 and -500<R 102 <-100; the unit of the above-mentioned radius of curvature is mm.

[0050] Constraining the curvature radius of all lenses according to the technical features described above has the following beneficial effects: ① It is helpful to reduce the difficulty of the lens manufacturing process; ② It is helpful to reduce the tolerance sensitivity of the lens and improve the yield of lens assembly.

[0051] The lens is used for a 0.47-inch DMD chip (DMD is a digital micromirror device), with a high degree of matching, 0.5 < projection ratio < 1.35. The optical power of the lens is greater than zero, that is, the lens as a whole has a positive optical power. The lens is suitable for short-wave monochromatic light sources in the range of 400nm ± 5nm.

[0052] Embodiment 1:

[0053] The total optical length of the lens is 100.68mm, based on a 0.47-inch DMD chip, 0% offset bias rate, projection ratio 1.04, focal length EFFL=13.5mm, aperture F=2.0, main light angle CRA<0.5°, and projection distance 150mm.

[0054] The specific parameters of the lens of this embodiment are shown in Table 1 below, which include the curvature radius, thickness, glass material, and semi-aperture of the lens.

[0055] Table 1

[0056]

[0057]

[0058] The optical architecture and optical path diagram of this embodiment are shown in Figure 1 and Figure 2 As shown, the optical distortion diagram of this embodiment is as shown in Figure 3 As shown, the optical distortion is less than 0.2%, which is conducive to high-quality restoration of 3D printing; the MTF diagram of this embodiment is as follows Figure 4 As shown, the average MTF of each field of view is greater than 0.79, and the imaging is good; the defocus MTF diagram of this embodiment is as follows Figure 5 As shown, the defocus range of MTF>0.3 is greater than 0.023mm, which has a larger defocus range and can adapt to unstable lighting environments; the relative illumination diagram of this embodiment is as shown Figure 6 As shown, the relative illumination at the edge to the center is greater than 98%, which indicates that the image brightness of the lens imaging image described in this embodiment is uniform, the light energy loss at the edge is small, and the utilization rate of the illumination light is high.

[0059] In order to make the lens compatible with more usage scenarios, the fourth lens 4 is allowed to be movable and focused, so that it is compatible with a certain projection distance range. The movable focusing of the fourth lens 4 is illustrated below with an example:

[0060] ① The projection distance becomes 125mm: Only the fourth lens 4 in the lens is moved right by 0.413mm, and the other lenses and the total length of the lens remain unchanged. The defocus MTF graph and optical distortion graph after the fourth lens 4 is moved right by 0.413mm are as follows Figure 7 and Figure 8 As shown, the performance is as follows: MTF>0.72, distortion 0.45%, meeting the basic requirements of 3D printing optical machines.

[0061] ② The projection distance becomes 175mm: Only the fourth lens element 4 in the lens moves left by 0.332mm, and the other lenses and the total length of the lens remain unchanged. The defocus MTF graph and optical distortion graph after the fourth lens element 4 moves left by 0.332mm are as follows Fig. 9 and Fig.10 As shown, the performance is as follows: MTF>0.67, distortion 0.39%, meeting the basic requirements of 3D printing optical machines.

[0062] Embodiment 2:

[0063] The total optical length of the lens is 100.68mm; the projection ratio is 1.04; the aperture is F=2; the focal length is EFFL=13.7mm; and the main light angle is CRA<0.5°.

[0064] The specific parameters of the lens of this embodiment are shown in Table 2 below, which include the curvature radius, thickness, glass material, and semi-aperture of the lens.

[0065] Table 2

[0066]

[0067]

[0068] The optical path diagram of this embodiment is as follows Fig.11 As shown, the MTF diagram of this embodiment is as follows Fig.12 As shown, the defocus MTF diagram of this embodiment is as follows Fig.13 As shown, the optical distortion diagram of this embodiment is as shown in Fig.14 As shown, the relative illumination diagram of this embodiment is as shown in Fig.15 As shown in the figure, the MTF, through-focus MTF, distortion, and relative illumination of the lens described in this embodiment all meet the imaging requirements of the 3D printing lens.

[0069] A projection device includes the lens described above, wherein the lens, a galvanometer 12, an equivalent turning prism 13 and an image source are sequentially arranged in the opposite direction of the light path. The image source includes a spatial light modulator 14 and a projection light source; wherein the projection light source is used to generate illumination light, the illumination light is modulated into image light by the spatial light modulator 14, the image light is projected to the lens, and a projection picture is formed by the lens and presented on a projection screen.

[0070] The galvanometer 12, the equivalent turning prism 13 and the image source etc. can adopt the existing technology, and their structure and working principle are not described in detail here.

[0071] This projection device adopts the projection lens described above, which can be matched with the 0.47-inch DMD chip in the DLP technology. The lens offset rate can reach 0%, the optical distortion is small, the imaging is good, and the projection quality is high.

[0072] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A 3D printed lens, characterized in that: It includes a front lens group, a diaphragm, and a rear lens group sequentially arranged in the direction from the object plane to the image plane. The focal length of the lens is 10mm < f < 17mm, the focal length of the front lens group is -100mm < f 前 < -50mm, and the focal length of the rear lens group is 15mm < f 后 < 25mm.

2. The 3D printed lens according to claim 1, characterized in that: The front lens group includes a first lens, a second lens, a third lens, and a fourth lens sequentially arranged in the direction from the object plane to the aperture. The first lens and the fourth lens are positive focal length lenses, and the second lens and the third lens are negative focal length lenses.

3. The 3D printed lens according to claim 2, characterized in that: The rear lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens sequentially arranged in the direction from the aperture to the image plane. The fifth lens, the eighth lens, the ninth lens, and the tenth lens are positive focal length lenses, and the sixth lens and the seventh lens are negative focal length lenses.

4. The 3D printed lens according to claim 2, characterized in that: The fourth lens is a movable focusing lens, and the projection distance of the lens is 150 mm ± 25 mm.

5. The 3D printed lens according to claim 3, characterized in that: The focal length of the seventh lens satisfies -16 mm < f7 < -5 mm or -30 mm < f7 < -17 mm; and / or, the focal length of the ninth lens satisfies 10 mm < f9 < 51 mm.

6. The 3D printed lens according to claim 2, characterized in that: The ratio of the air gap between the third lens and the fourth lens to the overall optical length of the lens is 0.02 ≤ Air3 / overall length < 0.

15.

7. The 3D printed lens according to claim 3, characterized in that: The ratio of the air gap between the fourth lens and the aperture to the overall optical length of the lens is 0.02 ≤ Air4 / overall length < 0.15; the ratio of the air gap between the aperture and the fifth lens to the overall optical length of the lens is 0.02 ≤ Air aperture / overall length < 0.

1.

8. The 3D printed lens according to any one of claims 1 to 7, characterized in that: The lens is used for a 0.47-inch DMD chip, and 0.5 < projection ratio < 1.

35.

9. The 3D printed lens according to any one of claims 1 to 7, characterized in that: The lens is applicable to a short-wave monochromatic light source in the range of 400 nm ± 5 nm.

10. A projection device, characterized in that: Including the lens according to any one of claims 1 to 7, there are sequentially arranged, against the optical path direction, the lens, a galvanometer scanner, an equivalent turning prism, and an image source.

11. The projection device according to claim 10, characterized in that: The image source includes a spatial light modulator and a projection light source.

Images