A high-definition zoom lens applied to micro-nano high-precision 3D printing

Abstract

The embodiment of the application discloses a high-definition zoom lens applied to micro-nano high-precision 3D printing, comprising: coaxially arranged lens groups with positive light angles, a diaphragm, a light splitting device, a galvanometer, a protective glass and an imaging surface, wherein the lens groups comprise coaxially arranged first group lenses and second group lenses in sequence, and the diaphragm is located between the first group lenses and the second group lenses. Through the high-definition zoom lens, the printing pixel size can be continuously changed, the lens distortion is small, the relative luminance is high, the light efficiency is high, and the use requirements are met.

Description

Technical Field

[0001] This invention relates to the field of zoom lens technology, and in particular to a high-definition zoom lens for use in micro-nano high-precision 3D printing. Background Technology

[0002] 3D printing technology, also known as "rapid prototyping technology," is a three-dimensional modeling method that uses computer graphics files as a basis to build up materials layer by layer. 3D micro / nano printing, in particular, has great potential and significant advantages in manufacturing complex three-dimensional micro / nano structures and high aspect ratio micro / nano structures. It also boasts advantages such as simple equipment, high efficiency, wide range of materials, and direct molding.

[0003] Current micro-nano printing systems are highly customized, and different printing sizes require the use of multiple objectives. In the field of photopolymerization printing, due to the differences in curing efficiency of materials, there are also higher requirements for ultraviolet band bandwidth. Fixed-focus lenses with single wavelength narrow bands can no longer meet the usage needs.

[0004] Therefore, it is necessary to design a new zoom lens that can achieve continuously variable printing pixel size, low lens distortion, high relative illumination, and high light efficiency to meet usage requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a high-definition zoom lens for micro-nano high-precision 3D printing.

[0006] To solve the above-mentioned technical problems, the purpose of this invention is achieved through the following technical solution: providing a high-definition zoom lens for micro-nano high-precision 3D printing, comprising: a lens group with positive optical power, an aperture stop, a beam splitter, a galvanometer, a protective glass, and an imaging surface arranged coaxially, wherein the lens group includes a first group of lenses and a second group of lenses arranged coaxially in sequence, and the aperture stop is located between the first group of lenses and the second group of lenses.

[0007] The further technical solution is as follows: the first group of lenses includes a fifth lens, a fourth lens and a third lens arranged in sequence; the third lens is a lens with negative optical power, the fourth lens is a lens with positive optical power and the third lens is a lens with positive optical power.

[0008] The further technical solution is as follows: the second group of lenses includes a second lens and a first lens arranged in sequence, the first lens being a lens with negative optical power and the second lens being a lens with positive optical power.

[0009] The further technical solution is as follows: the ratio of the focal length of the first lens to the focal length of the lens group of the objective lens system is -1.653.

[0010] A further technical solution thereof is that the ratio of the focal length of the second lens to the focal length of the objective lens system lens group is 1.531.

[0011] A further technical solution thereof is that the ratio of the focal length of the third lens to the focal length of the objective lens system lens group is -0.704.

[0012] A further technical solution thereof is that the ratio of the focal length of the fourth lens to the focal length of the objective lens system lens group is 0.662.

[0013] A further technical solution thereof is that the ratio of the focal length of the fifth lens to the focal length of the objective lens system lens group is 1.948.

[0014] A further technical solution thereof is that the first group of lenses and the second group of lenses satisfy the following conditional formula:

[0015] 3.6 < T L / f / IH < 5.0, where T L represents the total optical length of the first group of lenses and the second group of lenses, f represents the effective focal length of the first group of lenses and the second group of lenses, and IH represents the actual semi-image height of the first group of lenses and the second group of lenses.

[0016] A further technical solution thereof is that the first group of lenses and the second group of lenses satisfy the following conditional formula:

[0017] 19.3mm < IH / tanθ < 36.2mm; where IH represents the actual semi-image height of the first group of lenses and the second group of lenses, and θ represents the semi-field angle of the first group of lenses and the second group of lenses.

[0018] The beneficial effects of the present invention compared with the prior art are as follows: The present invention includes a first group of lenses with positive optical power, an aperture stop, a second group of lenses with positive optical power, a beam splitter device, a protective glass, and an imaging surface arranged coaxially in sequence, and is paired with a 0.3-inch DMD chip, which can be compatible with XPR technology to achieve 2K resolution; it realizes continuously variable printed pixel size, small lens distortion, high relative illumination, high light efficiency, and meets the usage requirements.

[0019] The following further describes the present invention in conjunction with the attached drawings and specific embodiments. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 A 2D layout diagram of a high-definition zoom lens for micro-nano high-precision 3D printing in a 16µm state, provided as an embodiment of the present invention;

[0022] Figure 2 The spatial frequency MTF diagram of a high-definition zoom lens for micro-nano high-precision 3D printing provided in this embodiment of the invention at a 16µm state;

[0023] Figure 3 A dot plot of a high-definition zoom lens for micro-nano high-precision 3D printing at 16µm, provided as an embodiment of the present invention;

[0024] Figure 4 A field curvature evaluation diagram of a high-definition zoom lens applied to micro-nano high-precision 3D printing at 16µm, provided as an embodiment of the present invention;

[0025] Figure 5 This invention provides a distortion evaluation diagram of a high-definition zoom lens applied to micro-nano high-precision 3D printing at a 16µm state, as provided in an embodiment of the invention.

[0026] Figure 6 A relative illumination diagram of a high-definition zoom lens for micro-nano high-precision 3D printing at 16µm, provided as an embodiment of the present invention;

[0027] Figure 7 A 2D layout diagram of a high-definition zoom lens applied to micro-nano high-precision 3D printing in a 10µm state, provided as an embodiment of the present invention;

[0028] Figure 8 The spatial frequency MTF diagram of a high-definition zoom lens for micro-nano high-precision 3D printing provided in this embodiment of the invention at a 10µm state;

[0029] Figure 9 A dot plot of a high-definition zoom lens for micro-nano high-precision 3D printing at 10µm, provided as an embodiment of the present invention;

[0030] Figure 10 This invention provides a field curvature evaluation diagram of a high-definition zoom lens applied to micro-nano high-precision 3D printing at a 10µm state;

[0031] Figure 11 This invention provides a distortion evaluation diagram of a high-definition zoom lens applied to micro-nano high-precision 3D printing at a 10µm state, as provided in an embodiment of the invention.

[0032] Figure 12A relative illumination diagram of a high-definition zoom lens for micro-nano high-precision 3D printing at a 10µm state, provided as an embodiment of the present invention;

[0033] Explanation of the markings in the image:

[0034] 1. Lens group; 2. Aperture stop; 3. Beam splitter; 4. Galvanometer; 5. Protective glass; 6. Imaging plane; G01, First lens; G02, Second lens; G03, Third lens; G04, Fourth lens; G05, Fifth lens. Detailed Implementation

[0035] 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, not all, of the embodiments of the present invention. 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.

[0036] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0037] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0039] Please see Figure 1 , Figure 1This is a 2D layout diagram of a high-definition zoom lens for micro-nano high-precision 3D printing, shown in an embodiment of the present invention, in a 16µm state. This lens is specifically a 3D printing optical engine system based on DLP technology, applicable to 3D micro-nano printing scenarios. DLP (Digital Lighting Processor) technology is a spatial light modulation technology based on a DMD (Digital Mirror Device) chip. It boasts advantages such as fast response, high efficiency, and high reliability, and has wider applications not only in projection display but also in industry. The DMD chip consists of a series of micrometer-scale mirror arrays, with each pixel micromirror switching at a speed of 32kHz. It has a wide spectral range, applicable not only to the visible spectrum but also supporting the ultraviolet (UV) to near-infrared (NIR) bands. This lens, paired with a 0.3-inch DMD chip, is compatible with XPR technology, achieving 2K resolution; without XPR, it achieves 720P resolution. The lens offers advantages such as continuously variable printing pixel size from 10 to 16µm, low lens distortion, high relative illumination, and high luminous efficiency. Taking into account and balancing practical application scenarios, manufacturing, cost, distortion, image quality, projection brightness, etc., it has a series of advantages such as high imaging quality, fewer lenses, minimal distortion, reasonable tolerance, and low cost.

[0040] Please see Figure 1 A high-definition zoom lens for micro-nano high-precision 3D printing includes: a lens group 1 with positive optical power, an aperture 2, a beam splitter 3, a galvanometer 4, a protective glass 5, and an imaging surface 6, all arranged coaxially. The lens group 1 includes a first group of lenses and a second group of lenses arranged coaxially in sequence, and the aperture 2 is located between the first group of lenses and the second group of lenses.

[0041] The first group of lenses includes a fifth lens G05, a fourth lens G04, and a third lens G03 arranged in sequence; the third lens G03 is a lens with negative optical power, the fourth lens G04 is a lens with positive optical power, and the fifth lens G05 is a lens with positive optical power.

[0042] The second group of lenses includes a second lens G02 and a first lens G01 arranged in sequence. The first lens G01 is a lens with negative optical power, and the second lens G02 is a lens with positive optical power.

[0043] In this embodiment, the lenses of the aforementioned high-definition zoom lens are all made of glass, and all lenses are spherical lenses.

[0044] The group lens material of this embodiment has high transmittance for light with wavelengths of 380nm to 410nm, and the wavelength range is 380 to 410nm, which can accommodate both 385nm and 405nm light sources.

[0045] Please see Figure 1 The first lens is a zoom group.

[0046] In one embodiment, please refer to Figure 1 The ratio of the focal length of the first lens G01 to the focal length of the objective lens system is -1.653.

[0047] In one embodiment, please refer to Figure 1 The ratio of the focal length of the second lens G02 to the focal length of the objective lens system is 1.531.

[0048] In one embodiment, please refer to Figure 1 The ratio of the focal length of the third lens G03 to the focal length of the objective lens system is -0.704.

[0049] In one embodiment, please refer to Figure 1 The ratio of the focal length of the fourth lens G04 to the focal length of the objective lens system is 0.662.

[0050] In one embodiment, please refer to Figure 1 The ratio of the focal length of the fifth lens G05 to the focal length of the objective lens system is 1.948.

[0051] In this embodiment, the zoom range of the objective lens system lens group is 20-35mm.

[0052] In one embodiment, the first group of lenses and the second group of lenses satisfy the following condition:

[0053] 3.6 <T L / f / IH<5.0, where T L The first group of lenses and the second group of lenses represent the total optical length, f represents the effective focal length of the first group of lenses and the second group of lenses, and IH represents the actual half-image height of the first group of lenses and the second group of lenses.

[0054] Satisfies 3.6 <T L When / f / IH < 5.0, the relationship between the total length of the lens and its resolving power can be reasonably balanced. L When the / f / IH value exceeds the upper limit, the overall length of the lens becomes too large (the imaging system becomes too large). If the overall length is scaled proportionally or forcibly compressed, the image height will be insufficient. L When the value of / f / IH is below the lower limit, the lens aberration correction becomes difficult due to the excessive optical focal length of each lens, resulting in a significant decrease in resolving power.

[0055] In one embodiment, the first group of lenses and the second group of lenses satisfy the following conditional expression:

[0056] 19.3mm < IH / tanθ < 36.2mm; where IH represents the actual half image height of the first group of lenses and the second group of lenses, and θ represents the half field angle of the first group of lenses and the second group of lenses.

[0057] When 19.3mm < IH / tanθ < 36.2mm is satisfied, the distortion of the optical lens can be reasonably limited, and the difficulty of distortion correction can be reduced. When the value of IH / tanθ exceeds the lower limit, the distortion of the lens will increase in the negative direction; when the value of IH / tanθ exceeds the upper limit, the distortion of the lens will increase in the positive direction. At the same time, the field of view size can be limited, and then the size of the projection frame can be controlled.

[0058] In this embodiment, the optical lens satisfies the following conditional expression: CRA < 2°; where CRA represents the principal ray incident angle of the first group of lenses and the second group of lenses on the imaging surface.

[0059] When the conditional expression is satisfied, it can well match the DMD chip and achieve a good projection effect.

[0060] The specific parameter table of the 16um objective lens system, that is, the specific parameters of the high-definition zoom lens in the 16um state, is shown in Table 1:

[0061] Table 1. Specific Parameter Table of 16um Objective Lens System

[0062]

[0063] The projection lens obtained according to the specific parameters of each of the above lenses, such as Figure 1 shown in the 2D Layout of the objective lens system.

[0064] The MTF (Modulation Transfer Function) index is the most accurate and scientific evaluation standard for lenses at present. The ordinate is the contrast, and the closer it is to 1, the better the lens imaging. The abscissa represents the resolution, with the unit of line pairs per millimeter. The pixel size of the image source adopted in this embodiment is 5.4um, and the corresponding designed resolution is 93 line pairs per millimeter. Generally, the projection lens is required to have an MTF value of at least 0.3 or more in each field of view at the design stage, and the MTF values of each field of view in this embodiment are all above 0.58, as Figure 2 shown.

[0065] Such as Figure 3The diagram shows the dot matrix of the lens's various fields of view. The smaller the spot radius of each field of view, the better the image quality. Generally, an RMS of less than the pixel size (5.4µm) across the entire field of view is considered excellent. In this embodiment, the RMS across the entire field of view is less than 1.8µm, which is considered very excellent.

[0066] like Figure 4 and Figure 5 As shown, 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 value. The system distortion in this embodiment is within 0.2%.

[0067] like Figure 6 As shown, the edge illumination reaches 99%, which results in excellent uniformity of the projection effect on the system's imaging surface.

[0068] Please see Figure 7 At 10µm resolution, the structure used in high-definition zoom lenses is the same, the difference being:

[0069] The specific parameters of the 10µm objective lens system are shown in Table 2:

[0070] Table 2.10µm Objective Lens System Specific Parameters

[0071]

[0072] like Figure 8 As shown, the MTF (Mean Transmission Factor) is currently the most accurate and scientific evaluation standard for lenses. The vertical axis represents contrast ratio; the closer it is to 1, the better the lens 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 in this embodiment, the MTF values ​​for each field of view are all above 0.55.

[0073] like Figure 9 As shown, the smaller the spot radius of each field of view, the better the imaging quality. Generally, an RMS of less than the pixel size (5.4µm) across the entire field of view is considered excellent. In this embodiment, the RMS across the entire field of view is less than 3.32µm, which is considered very excellent.

[0074] like Figure 10 and Figure 11 As shown, 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 value. The system distortion in this embodiment is within 0.2%.

[0075] like Figure 12As shown, the edge illumination reaches 99%, which results in excellent uniformity of the projection effect on the system's imaging surface.

[0076] In this embodiment, the high-definition zoom lens used in micro-nano high-precision 3D printing, at a 10µm resolution, has a projected pixel size of 16µm corresponding to a working distance of 30mm. A 10µm projected pixel size corresponds to a working distance of 20mm. The projected pixel size ranges from 10µm to 16µm. The lens uses a 0.3-inch DMD chip. The lens has high relative illumination, which is beneficial for improving optomechanical uniformity. The selected lens material has high transmittance for light wavelengths from 380nm to 410nm.

[0077] The high-definition zoom lens of this embodiment boasts high light efficiency and low distortion, meeting the requirements of desktop high-precision 3D printing equipment. It is compatible with XPR technology, achieving 2K resolution when using XPR and 720P resolution when not using XPR. The relative illumination across the entire field of view exceeds 99%, and the MTF across the entire field of view exceeds 0.55, resulting in excellent image quality. With a wavelength range of 380–410 nm, it can accommodate both 385 nm and 405 nm light sources. This high-definition zoom lens of the embodiment achieves a reasonable balance between magnification, image brightness, cost, image quality, and resolution. Furthermore, the objective lens system proposed with full consideration of practical applications and manufacturing processes offers a series of advantages, including high image quality, a small number of lenses, minimal distortion, reasonable tolerances, and low cost. It possesses high practical application value.

[0078] The aforementioned high-definition zoom lens for micro-nano high-precision 3D printing consists of a first group of lenses with positive optical power, an aperture 2, a second group of lenses with positive optical power, a beam splitter 3, a protective glass 5, and an imaging surface 6 arranged coaxially in sequence. The lens is equipped with a 0.3-inch DMD chip, which is compatible with XPR technology and can achieve 2K resolution. It enables continuously variable printing pixel size, low lens distortion, high relative illumination, and high light efficiency, meeting the application requirements.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-definition zoom lens for micro / nano high-precision 3D printing, characterized in that, Including: A lens group with positive optical power, an aperture stop, a beam splitter, a galvanometer scanner, a protective glass, and an imaging surface that are coaxially arranged. The lens group consists of a first group of lenses and a second group of lenses arranged coaxially in sequence. The aperture stop is located between the first group of lenses and the second group of lenses. The first group of lenses consists of a fifth lens, a fourth lens, and a third lens arranged in sequence. The third lens is a lens with negative optical power, the fourth lens is a lens with positive optical power, and the fifth lens is a lens with positive optical power. The second group of lenses consists of a second lens and a first lens arranged in sequence. The first lens is a lens with negative optical power, and the second lens is a lens with positive optical power. The first group of lenses and the second group of lenses satisfy the following conditional expressions: 3.6mm -1 <T L / f / IH<5.0mm -1 , among which, T L The first group of lenses and the second group of lenses represent the total optical length, f represents the effective focal length of the first group of lenses and the second group of lenses, and IH represents the actual half-image height of the first group of lenses and the second group of lenses.

2. The high-definition zoom lens for micro-nano high-precision 3D printing according to claim 1, characterized in that, The ratio of the focal length of the first lens to the focal length of the high-definition zoom lens group is -1.

653.

3. A high-definition zoom lens for micro-nano high-precision 3D printing according to claim 1, characterized in that, The ratio of the focal length of the second lens to the focal length of the high-definition zoom lens group is 1.

531.

4. A high-definition zoom lens for micro / nano high-precision 3D printing according to claim 1, characterized in that, The ratio of the focal length of the third lens to the focal length of the high-definition zoom lens group is -0.

704.

5. A high-definition zoom lens for micro-nano high-precision 3D printing according to claim 1, characterized in that, The ratio of the focal length of the fourth lens to the focal length of the high-definition zoom lens group is 0.

662.

6. A high-definition zoom lens for micro-nano high-precision 3D printing according to claim 1, characterized in that, The ratio of the focal length of the fifth lens to the focal length of the high-definition zoom lens group is 1.

948.

7. A high-definition zoom lens for micro-nano high-precision 3D printing according to claim 1, characterized in that, The first group of lenses and the second group of lenses satisfy the following conditional expressions: 19.3mm < IH / tanθ < 36.2mm; where IH represents the actual semi-image height of the first group of lenses and the second group of lenses, and θ represents the semi-field angle of the first group of lenses and the second group of lenses.

Images