An ultra-high-definition low-distortion lens

Abstract

The application provides a kind of super high definition low distortion lens, comprising: diaphragm, lens group, light splitting device, galvanometer, protective glass and image plane arranged in sequence;Light from image plane, through protective glass, galvanometer, light splitting device, lens group and diaphragm in projection plane imaging in sequence;Image plane is used to realize the closure of light;Galvanometer is used to increase pixel;Light splitting device is used to split beam;Diaphragm is used to control the amount of light;Lens group is used to correct aberration;Lens group includes: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens;First lens, second lens, third lens, fifth lens and seventh lens are all lenses with positive focal power;Fourth lens and sixth lens are both lenses with negative focal power.The application solves the problem of insufficient machining precision and surface roughness in the prior art.

Description

Technical Field

[0001] This invention relates to the field of projection lens technology, and in particular to an ultra-high-definition low-distortion lens. Background Technology

[0002] 3D printing technology, as a rapid prototyping technology, fulfills people's pursuit of efficient, precise, personalized, and customized products through its unique manufacturing methods. To date, this technology has expanded beyond simply providing models and prototypes for industrial design or mechanical manufacturing. Its applications span jewelry, food, industrial design, architecture, engineering, automotive, aerospace, medical industry, education, geographic information systems, civil engineering, and the military. The principle of photopolymer 3D printing technology is that the activation energy generated by ultraviolet light, the highest energy in the spectrum, breaks the C-C bonds in unsaturated polyester resin, generating free radicals that thus cure the resin.

[0003] Currently, 3D printing still has many shortcomings, such as unstable mechanical properties of printed parts, insufficient processing accuracy and surface roughness, and inadequate distortion in some special printing scenarios. Most current DLP printing systems project pixels at a magnification of tens or even hundreds of times, which is insufficient for nanoscale printing accuracy and results in insufficiently fine textures. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an ultra-high-definition low-distortion lens. This invention solves the problems of insufficient processing precision and surface roughness in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] An ultra-high-definition, low-distortion lens includes:

[0007] The aperture stop, lens assembly, beam splitter, galvanometer, protective glass, and image plane are arranged in sequence.

[0008] The light rays are emitted from the image plane and pass sequentially through the protective glass, the galvanometer, the beam splitter, the lens group, and the aperture to form an image on the projection plane;

[0009] The image plane is used to close the light rays; the galvanometer is used to increase the number of pixels; the beam splitter is used to split the light rays; the aperture is used to control the amount of light entering the lens; the lens group is used to correct aberrations.

[0010] The lens assembly includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens; the first lens, the second lens, the third lens, the fifth lens, and the seventh lens are all lenses with positive optical power; the fourth lens and the sixth lens are both lenses with negative optical power.

[0011] Preferably, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are all spherical lenses.

[0012] Preferably, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens are all made of glass.

[0013] Preferably, the ratio of the focal length of the first lens to the focal length of the distortion lens is 0.499; the ratio of the focal length of the second lens to the focal length of the distortion lens is 0.540; the ratio of the focal length of the third lens to the focal length of the distortion lens is 0.534; the ratio of the focal length of the fourth lens to the focal length of the distortion lens is -0.194; the ratio of the focal length of the fifth lens to the focal length of the distortion lens is 0.335; the ratio of the focal length of the sixth lens to the focal length of the distortion lens is -0.237; and the ratio of the focal length of the seventh lens to the focal length of the distortion lens is 0.405.

[0014] Preferably, the MTF value of each field of view of the distorted lens is greater than 0.6; the RMS value of the entire field of view of the distorted lens is less than 2.6µm.

[0015] Preferably, the optical distortion of the distortion lens is less than 0.05%, and the TV distortion is less than 0.02%.

[0016] Preferably, the relative illumination and edge illumination of the distorted lens are 99%.

[0017] Preferably, the distortion lens uses a 0.3-inch DMD chip.

[0018] Preferably, the projection plane pixels of the distorted lens are 0.36 times smaller than the image plane pixels.

[0019] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0020] This invention provides an ultra-high-definition low-distortion lens. By selecting the lens material and setting the number and material of the lens elements in the lens group, this invention solves the problems of insufficient processing precision and surface roughness in the prior art. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a structural diagram of a distortion lens provided in an embodiment of the present invention;

[0023] Figure 2 Spatial frequency MTF diagram provided for embodiments of the present invention;

[0024] Figure 3 A point diagram of the field of view of a distorted lens provided in an embodiment of the present invention;

[0025] Figure 4 The field curvature evaluation diagram provided in the embodiments of the present invention;

[0026] Figure 5 The distortion evaluation diagram provided in the embodiments of the present invention;

[0027] Figure 6 The relative illumination diagram is provided for an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1-Aperture, 2-Lens group, 3-Beam splitter, 4-Galvanometer, 5-Protective glass, 6-Image plane, G01-First lens, G02-Second lens, G03-Third lens, G04-Fourth lens, G05-Fifth lens, G06-Sixth lens, G07-Seventh lens. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, including a series of steps, processes, methods, etc., is not limited to the steps listed, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products, or devices.

[0033] The purpose of this invention is to provide an ultra-high-definition, low-distortion lens, which solves the problems of insufficient processing precision and surface roughness in the prior art.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, the present invention provides an ultra-high-definition low-distortion lens, comprising:

[0036] The following components are arranged in sequence: aperture 1, lens group 2, beam splitter 3, galvanometer 4, protective glass 5, and image plane 6.

[0037] The light rays are emitted from the image plane 6 and pass sequentially through the protective glass 5, the galvanometer 4, the beam splitter 3, the lens group 2, and the aperture 1 to form an image on the projection plane;

[0038] The image plane 6 is used to open or close the pixel lens to close the light beam; the galvanometer 4 is mainly used to make the lens vibrate through external force, so as to increase the number of pixels (compatible with XPR technology, the system cannot realize XPR technology without the galvanometer 4); the beam splitter 3 is mainly used to split the beam between the illumination system and the imaging system; the aperture 1 is used to control the amount of light entering; the lens group 2 is used to correct aberrations.

[0039] The lens group 2 includes: a first lens G01, a second lens G02, a third lens G03, a fourth lens G04, a fifth lens G05, a sixth lens G06, and a seventh lens G07; the first lens G01, the second lens G02, the third lens G03, the fifth lens G05, and the seventh lens G07 are all lenses with positive optical power; the fourth lens G04 and the sixth lens G06 are both lenses with negative optical power.

[0040] Furthermore, the first lens G01, the second lens G02, the third lens G03, the fourth lens G04, the fifth lens G05, the sixth lens G06, and the seventh lens G07 are all spherical lenses.

[0041] Furthermore, the first lens G01, the second lens G02, the third lens G03, the fourth lens G04, the fifth lens G05, the sixth lens G06, and the seventh lens G07 are all made of glass.

[0042] Furthermore, the ratio of the focal length of the first lens G01 to the focal length of the distortion lens is 0.499; the ratio of the focal length of the second lens G02 to the focal length of the distortion lens is 0.540; the ratio of the focal length of the third lens G03 to the focal length of the distortion lens is 0.534; the ratio of the focal length of the fourth lens G04 to the focal length of the distortion lens is -0.194; the ratio of the focal length of the fifth lens G05 to the focal length of the distortion lens is 0.335; the ratio of the focal length of the sixth lens G06 to the focal length of the distortion lens is -0.237; and the ratio of the focal length of the seventh lens G07 to the focal length of the distortion lens is 0.405.

[0043] Table 1 shows the specific parameters of the distortion lens.

[0044] Table 1. Specific parameters of the distortion lens

[0045] Surface serial number radius of curvature / mm Thickness / mm Spacing / mm Nd Vd illustrate S0 unlimited 22 S1 unlimited 0.074 Aperture 1 S2 -156.431 2.099 1.603 65.46 Lens G1 S3 -17.055 0.1 S4 30.896 3.508 1.620 60.37 Second lens G2 S5 -64.901 0.1 S6 15.911 4.303 1.741 52.68 3rd lens G3 S7 38.108 0.349 S8 -124.541 3.573 1.699 30.05 Lens G4 (4th lens) S9 9.775 2.488 S10 9.942 2.225 1.603 65.46 Lens G5 (5th lens) S11 40.808 0.1 S12 18.075 9.107 1.729 54.67 Lens G6 (6th lens) S13 5.357 14.512 S14 87.96 8 1.517 64.21 Lens G7 (7th lens) S15 -15.102 4.143 S16 unlimited 18 1.713 53.87 Spectrometer 3 S17 unlimited 1.65 S18 unlimited 2 1.523 58.57 Galvanometer 4 S19 unlimited 2 S20 unlimited 1.1 1.517 64.21 Protective glass 5 S21 unlimited 0.303 S22 unlimited Image 6

[0046] Furthermore, such as Figure 2-3 As shown, the MTF value of each field of view of the distorted lens is greater than 0.6; the RMS value of the entire field of view of the distorted lens is less than 2.6µm.

[0047] MTF (Modulation Transfer Function) is currently the most accurate and scientific evaluation standard for lenses. The vertical axis represents contrast ratio; the closer to 1, the better the image quality. The horizontal axis represents resolution, measured in line pairs per millimeter. The image source pixel size used in this embodiment is 5.4µm, corresponding to a design resolution of 93 line pairs per millimeter. Projection lenses generally require an MTF value of at least 0.3 for each field of view, while the MTF values ​​in this embodiment are all above 0.6. The smaller the spot radius in each field of view, the better the image quality. Generally, an RMS value less than the pixel size (5.4µm) across the entire field of view is considered excellent. The RMS value in this embodiment is less than 2.6µm across the entire field of view, which is considered very excellent.

[0048] Furthermore, such as Figure 4-5As shown, the optical distortion of the lens is less than 0.05%, and the TV distortion is less than 0.02%. The vertical axis represents the field of view of the lens. The horizontal axis of the field curvature plot represents the magnitude of the field curvature value, and the horizontal axis of the distortion plot represents the distortion amount. Distortion is a very important indicator of a projection lens; the embodiments of this application are applicable to demanding distortion scenarios. The system distortion of the embodiments of this application is within 0.05%, and the TV distortion is within 0.02%, which are excellent.

[0049] Furthermore, such as Figure 6 As shown, the relative illumination and edge illumination of the distortion lens are 99%, resulting in excellent uniformity of the projection effect on the system's imaging surface 6. This is beneficial for improving the uniformity of the optical mechanism.

[0050] Furthermore, the distortion lens employs a 0.3-inch DMD chip. The selected lens material has high transmittance for light wavelengths in the range of 380nm to 410nm.

[0051] Furthermore, the projection plane pixels of the distorted lens are reduced by a factor of 0.36 relative to the image plane pixels.

[0052] In this embodiment, the lens satisfies the following condition:

[0053] 0.3 <TL / f / IH<0.35 (1)

[0054] Wherein, TL represents the total optical length of the optical lens, f represents the effective focal length of the optical lens, and IH represents the actual half-image height of the optical lens.

[0055] When condition (1) is met, the relationship between the total length of the lens and the resolving power can be reasonably balanced. When the value of TL / f / IH exceeds the upper limit, the overall length of the lens is too large (the volume of the imaging system is too large). If the total length is scaled proportionally or forcibly compressed, the image height will be insufficient. When the value of TL / f / IH is lower than the lower limit, due to the excessive optical focal length of each lens, it is difficult to correct lens aberrations and the resolving power will decrease significantly.

[0056] In the implementation method, the optical lens satisfies the following condition:

[0057] 60mm <IH / tanθ<60.4mm (2)

[0058] Wherein, IH represents the actual half-image height of the optical lens, and θ represents the half-field angle of the optical lens.

[0059] When condition (2) is met, the distortion of the optical lens can be reasonably limited, reducing the difficulty of distortion correction. When the value of IH / tanθ exceeds the lower limit, the lens distortion will increase in the negative direction; when the value of IH / tanθ exceeds the upper limit, the lens distortion will increase in the positive direction. At the same time, the field of view can be limited, thereby controlling the size of the projected image.

[0060] In the implementation method, the optical lens satisfies the following condition:

[0061] CRA<1° (3)

[0062] Wherein, CRA represents the principal ray incident angle of the optical lens on the imaging plane 6.

[0063] When condition (3) is met, it can be well matched with the DMD chip and achieve good projection effect.

[0064] The beneficial effects of this invention are as follows:

[0065] (1) The 3D micro-nano high-precision printing projection lens disclosed in this invention has a small total length and ultra-low distortion, which meets the requirements of desktop high-precision 3D printing equipment.

[0066] (2) The 3D printing projection lens disclosed in this invention is compatible with XPR technology. When using XPR, it achieves 2K resolution; when not using XPR, it achieves 720P resolution.

[0067] (3) The 3D printing projection lens disclosed in this invention has a relative illumination of over 99% across the entire field of view and a MTF of over 0.6 across the entire field of view, resulting in excellent imaging quality; distortion can be reduced to within 0.05%, and TV distortion is within 0.02%, resulting in excellent distortion correction.

[0068] (4) The 3D printing projection lens disclosed in this invention uses glass material for all lenses, which can effectively avoid the problem of severe focus drift caused by the strong energy of the 405nm short-wave light source used in 3D printing and the easy heat absorption of plastic aspherical surfaces.

[0069] (5) The 3D printing projection lens disclosed in this invention has a wavelength range of 380 to 410 nm and can be used with both 385 nm and 405 nm light sources.

[0070] (6) The 3D printing projection lens disclosed in this invention has a spot radius (<2.6um) much smaller than the pixel size (5.4um), which is obviously advantageous for 3D printing, an application that focuses on spot size and energy concentration.

[0071] (7) The 3D printing projection lens disclosed in this invention has a high transmittance of light with a wavelength of 405nm, all exceeding 94% / 10mm. The energy absorption of the entire imaging system is relatively small, which can improve the overall brightness and reduce the system heat generation, reduce the power and size of the heat dissipation device, and help the stability during 3D printing.

[0072] (8) The 3D printed projection lens disclosed in this invention uses only 7 spherical lenses, and also does not use aspherical lenses. Compared with other lens designs with more than ten lenses, it greatly reduces the lens cost and assembly difficulty.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An ultra-high definition low-distortion lens, characterized by comprising: The application relates to a distortion lens. The distortion lens comprises, in sequence, a light barrier, a lens group, a light splitting device, a galvanometer, a protective glass and an image plane. Light rays are emitted from the image plane, sequentially pass through the protective glass, the galvanometer, the light splitting device, the lens group and the light barrier, and are imaged on a projection plane. The image plane is used to realize light ray closure; the galvanometer is used to increase pixels; the light splitting device is used to split light rays; the light barrier is used to control light quantity; and the lens group is used to correct aberration. The lens group is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens; the first lens, the second lens, the third lens, the fifth lens and the seventh lens are lenses with positive focal lengths; and the fourth lens and the sixth lens are lenses with negative focal lengths. The ratio of the focal length of the first lens to the focal length of the distortion lens is 0.499; the ratio of the focal length of the second lens to the focal length of the distortion lens is 0.540; the ratio of the focal length of the third lens to the focal length of the distortion lens is 0.534; the ratio of the focal length of the fourth lens to the focal length of the distortion lens is -0.194; the ratio of the focal length of the fifth lens to the focal length of the distortion lens is 0.335; the ratio of the focal length of the sixth lens to the focal length of the distortion lens is -0.237; and the ratio of the focal length of the seventh lens to the focal length of the distortion lens is 0.

405. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are spherical lenses.

2. The ultra-high definition low-distortion lens according to claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are made of glass.

3. The ultra-high definition low-distortion lens according to claim 1, wherein, The MTF value of each field of view of the distortion lens is greater than 0.6; and the full field of view RMS of the distortion lens is less than 2.6um.

4. The ultra-high definition low-distortion lens according to claim 1, wherein, The optical distortion of the distortion lens is less than 0.005%; and the TV distortion is less than 0.002%.

5. The ultra-high definition low-distortion lens according to claim 1, wherein, The relative luminance and edge luminance of the distortion lens are 99%.

6. The ultra-high definition low-distortion lens according to claim 1, wherein, The distortion lens adopts a 0.3-inch DMD chip.

7. The ultra-high definition low-distortion lens according to claim 1, wherein, The pixel points of the projection plane of the distortion lens are reduced by 0.36 times relative to the pixel points of the image plane.

Images