Lens with high imaging quality

Abstract

The utility model relates to the technical field of optics, in particular to a lens with high imaging quality, which comprises a magnification lens, a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an object plane to an image plane along the axial direction of the lens, the first lens, the second lens and the fifth lens are all concave-convex lenses, the third lens and the fourth lens are plano-concave lenses, and the sixth lens and the seventh lens are biconvex lenses. Multiple lenses are combined together to improve the imaging quality.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, and in particular to a lens with high imaging quality. Background Technology

[0002] DMD technology achieves precise modulation and projection of light through the precise control of micromirror arrays. To improve image quality, traditional lens designs typically employ multi-lens configurations, optimizing lens shapes, selecting high-performance materials, and finely adjusting the relative positions between lenses to minimize various aberrations, such as spherical aberration, off-axis aberration, and chromatic aberration. Reducing these aberrations is crucial for improving image sharpness, color reproduction, and contrast.

[0003] However, traditional lens configuration methods often face a challenge in balancing structural compactness and imaging performance when pursuing image quality. On the one hand, achieving higher image quality often requires increasing the number and complexity of lenses, which directly leads to increased lens size and weight, hindering the trend towards miniaturization and lightweight design. On the other hand, even with increased lens number and complexity, traditional configuration methods still struggle to achieve significant improvements in image quality while maintaining a compact lens structure, especially in complex lighting environments and extreme shooting conditions, where the stability and consistency of image quality still need to be strengthened.

[0004] Furthermore, traditional lens designs often suffer from deficiencies in imaging performance in the field region (i.e., the image edge region far from the lens optical axis), easily leading to problems such as image distortion and reduced resolution. Distortion, especially barrel and pincushion distortion, severely affects the geometric accuracy of the image and reduces its overall aesthetic appeal. Therefore, effectively controlling distortion in the field region and improving the imaging quality of the entire image area has become one of the key issues that urgently need to be addressed in the field of lens design.

[0005] Therefore, this application develops a high-image-quality lens to solve the problems existing in the prior art. Utility Model Content

[0006] The purpose of this invention is to provide a lens with high imaging quality to solve the problem of low imaging quality in DMD imaging in the prior art.

[0007] The technical solution of this utility model is: a high-imaging-quality lens, comprising: a magnification lens, a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the lens axis from the object plane to the image plane. The magnification lens is a plano-convex lens, the first lens, the second lens, and the fifth lens are all concave-convex lenses, the third lens and the fourth lens are plano-concave lenses, and the sixth lens and the seventh lens are biconvex lenses.

[0008] Preferably, the image-side surface of the magnification lens is convex, both sides of the first and second lenses are convex toward the object plane, the image-side surface of the third lens is concave, the object-side surface of the fourth lens is concave, and both sides of the fifth lens are convex toward the image plane.

[0009] Preferably, the distance between the center of the object side of the first lens and the center of the object side of the second lens is 2.5mm to 3mm, the distance between the center of the object side of the second lens and the center of the object side of the third lens is 2mm to 2.5mm, the distance between the center of the object side of the fourth lens and the center of the object side of the fifth lens is 10mm to 15mm, the distance between the center of the image side of the fifth lens and the center of the object side of the sixth lens is 0.5mm to 1.5mm, and the distance between the center of the image side of the sixth lens and the center of the object side of the seventh lens is 0.5mm to 1.5mm.

[0010] Preferably, the thickness of the first lens is 7mm to 11mm, the thickness of the second lens is 8mm to 12mm, the thickness of the third lens is 5mm to 9mm, the thickness of the fourth lens is 5mm to 7mm, the thickness of the fifth lens is 10mm to 12mm, the thickness of the sixth lens is 7mm to 9mm, and the thickness of the seventh lens is 6mm to 8mm.

[0011] Preferably, the distance between the seventh lens and the image plane is 80mm to 90mm, and the distance between the center of the image side of the magnification lens and the center of the object side of the first lens is 95mm to 105mm.

[0012] Preferably, the aperture stop is located between the third lens and the fourth lens, and the thickness of the aperture stop is 11.5mm to 12.5mm, and the distance between the center of the object side surface of the third lens and the object side surface of the aperture stop is 19mm to 21mm.

[0013] Compared with the prior art, the advantages of this utility model are:

[0014] (1) By setting multiple different lenses and accurately calculating the radius of curvature, thickness and distance between each lens, multiple lenses are combined and used together. The light is focused by the plano-convex magnification lens. The unique shape and power distribution of the concave and convex lenses of the first, second and fifth lenses effectively balance and correct the field curvature caused by other lenses. The strong light is focused by the biconvex lenses of the sixth and seventh lenses, and the light is focused more accurately on the image plane, thereby reducing the field curvature. The combination of plano-concave and concave-convex lenses effectively balances and corrects the distortion caused by uneven lens shape and power distribution. The strong light focusing of the biconvex lens can prevent the generation of distortion, thereby improving the image quality. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0016] Figure 1 This is a diagram showing the distribution of multiple lenses in a high-imaging-quality lens according to the present invention.

[0017] Figure 2 This is a dot diagram of a high-imaging-quality lens according to the present invention;

[0018] Figure 3 This is an OTF image of a high-imaging-quality lens according to the present invention.

[0019] Figure 4 This is a distortion field curve of a high-imaging-quality lens according to the present invention.

[0020] Among them: 1. Magnification lens; 2. First lens; 3. Second lens; 4. Third lens; 5. Aperture stop; 6. Fourth lens; 7. Fifth lens; 8. Sixth lens; 9. Seventh lens. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to specific embodiments:

[0022] like Figure 1 As shown, a high-imaging-quality lens includes a magnification lens 1 for adjusting the focal length or magnification of the imaging system. In the DMD imaging system, the plano-convex lens, as the magnification lens 1, can change the focusing characteristics of light, thereby adjusting the imaging focal length, increasing or decreasing the focal length to adapt to different imaging needs, maintaining the compactness of the imaging system, and providing the required focal length adjustment range. The design of the concave-convex lens helps to correct aberrations, thereby improving image quality. It can also effectively collect and focus light from the object surface, ensuring that the light can be uniformly projected onto the DMD. The plano-convex lens helps to further reduce aberrations, especially aberrations in the edge field of view, and can adjust the incident angle of light, ensuring that the light can smoothly transition to the subsequent lens group, significantly improving the resolution and contrast of the imaging system. The biconvex lens has positive optical power and can converge the light from the front lens and project it onto the DMD. The aperture stop 5 is located between the lens groups and its main function is to control the amount of light passing through, thereby adjusting the exposure of the image.

[0023] Furthermore, the first lens 2 and the second lens 3, as the front group lenses of the lens, are mainly responsible for collecting and focusing light from the object plane. The fact that both sides of the second lens bulge towards the object plane helps to enhance the light-collecting ability of the lens and reduce aberrations, enabling more effective light collection and increasing the light transmission of the lens. The concave image side of the third lens 4 helps to adjust the refraction path of light, reduce aberrations, and optimize image quality. It can more effectively control the refraction angle of light and reduce distortion during the imaging process. The concave object side of the fourth lens 6, in conjunction with other lenses, achieves precise control of light and can reduce the reflection and scattering of light on the lens surface, reducing the impact of stray light on image quality. The fifth lens 7, as one of the rear group lenses of the lens, is mainly responsible for adjusting the focusing position of light. The fact that both sides of the fifth lens bulge towards the image plane helps to enhance the light-converging ability of the lens and improve the image sharpness of the lens. In conjunction with other lenses, it can further reduce aberrations and improve the resolution and contrast of the image.

[0024] The specific parameters provided in this application are as follows:

[0025] Table 1: Relevant parameters of the lens in this application:

[0026]

[0027]

[0028] Based on the parameters of different lenses and aperture 5 in Table 1, the following can be obtained: Figure 2 As shown in the dot plot, the image point is always within the range of the blur spot. Specifically, the distance between the center of the object side of the first lens 2 and the center of the object side of the second lens 3 is 2.87 mm. A reasonable distance between the first lens 2 and the second lens 3 helps to reduce the overall impact of the ghost images generated by them on the imaging lens group, thereby improving the image quality. By controlling this distance, the effective radius of the object side and the image side of the first lens 2 can be controlled to a certain extent. An appropriate distance also helps to improve the stability of the optical system and reduce the degradation of image quality caused by vibration or temperature changes.

[0029] like Figure 3 As shown, a smooth and gradually decreasing MTF curve indicates that the optical system has a uniform ability to transmit contrast at different spatial frequencies, without any sudden drop or fluctuation at a certain frequency. This reflects that the image quality is uniform across the entire image range, without any obvious local distortion or blurring, and thus has high image quality.

[0030] like Figure 4 As shown, the curve did not shift significantly, which means that the distortion is small, the image is closer to the original object in shape, and there is no obvious distortion or deformation. The image is relatively clear throughout the entire field of view, and there is no obvious defocus phenomenon, which reflects the high image quality.

[0031] Specifically, the distance between the center of the object side of the second lens 3 and the center of the object side of the third lens 4 is 2.3 mm, the distance between the center of the object side of the fourth lens 6 and the center of the object side of the fifth lens 7 is 19.7 mm, the distance between the center of the image side of the fifth lens 7 and the center of the object side of the sixth lens 8 is 13.3 mm, the distance between the center of the image side of the fifth lens 7 and the center of the object side of the sixth lens 8 is 1 mm, and the distance between the center of the image side of the sixth lens 8 and the center of the object side of the seventh lens 9 is 1 mm.

[0032] The distance between the seventh lens 9 and the image plane is 85.49 mm, and the distance between the center of the image side of the magnification lens 1 and the center of the object side of the first lens 2 is 101.6 mm. The greater distance between the seventh lens 9 and the image plane allows sufficient space for light to diffuse and focus after passing through the seventh lens 9, thereby optimizing image quality. The greater distance between the center of the image side of the magnification lens 1 and the center of the object side of the first lens 2 ensures sufficient space between the magnification lens 1 and the first lens 2 to achieve better optical performance, which helps to reduce the reflection and scattering of light between the lenses and improve the clarity and contrast of the image.

[0033] Furthermore, the aperture 5 is located between the third lens 4 and the fourth lens 6, and the thickness of the aperture 5 is 12.95 mm. The distance between the center of the object side surface of the third lens 4 and the object side surface of the aperture 5 is 19.7 mm. The aperture 5, with its sufficient thickness, has mechanical stability and durability, ensuring that the imaging quality will not be affected by deformation or damage during long-term use. At the same time, the appropriate distance helps to maintain the relative position stability between the aperture 5 and the lens, reducing the degradation of imaging quality caused by vibration or temperature changes. Placing the aperture 5 between the third lens 4 and the fourth lens 6 can make full use of the imaging characteristics of these two lenses, and at the same time, the aperture 5 can be used to further optimize the imaging quality.

[0034] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and therefore, all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this utility model.

Claims

1. A lens with high imaging quality, characterized in that, include: The lens consists of a magnification lens (1), a first lens (2), a second lens (3), a third lens (4), an aperture stop (5), a fourth lens (6), a fifth lens (7), a sixth lens (8), and a seventh lens (9) arranged sequentially from the object plane to the image plane along the lens axis. The magnification lens (1) is a plano-convex lens, the first lens (2), the second lens (3), and the fifth lens (7) are all concave-convex lenses, the third lens (4) and the fourth lens (6) are plano-concave lenses, and the sixth lens (8) and the seventh lens (9) are biconvex lenses.

2. The high-imaging-quality lens according to claim 1, characterized in that: The image side of the magnification lens (1) is convex, the two sides of the first lens (2) and the second lens (3) are both convex toward the object plane, the image side of the third lens (4) is concave, the object side of the fourth lens (6) is concave, and the two sides of the fifth lens (7) are both convex toward the image plane.

3. The high-imaging-quality lens according to claim 1, characterized in that: The distance between the object-side center of the first lens (2) and the object-side center of the second lens (3) is 2.5mm to 3mm, the distance between the object-side center of the second lens (3) and the object-side center of the third lens (4) is 2mm to 2.5mm, the distance between the object-side center of the fourth lens (6) and the object-side center of the fifth lens (7) is 10mm to 15mm, the distance between the image-side center of the fifth lens (7) and the object-side center of the sixth lens (8) is 0.5mm to 1.5mm, and the distance between the image-side center of the sixth lens (8) and the object-side center of the seventh lens (9) is 0.5mm to 1.5mm.

4. A high-imaging-quality lens according to claim 1, characterized in that: The thickness of the first lens (2) is 7mm to 11mm, the thickness of the second lens (3) is 8mm to 12mm, the thickness of the third lens (4) is 5mm to 9mm, the thickness of the fourth lens (6) is 5mm to 7mm, the thickness of the fifth lens (7) is 10mm to 12mm, the thickness of the sixth lens (8) is 7mm to 9mm, and the thickness of the seventh lens (9) is 6mm to 8mm.

5. A high-imaging-quality lens according to claim 1, characterized in that: The distance between the seventh lens (9) and the image plane is 80mm to 90mm, and the distance between the center of the image side of the magnification lens (1) and the center of the object side of the first lens (2) is 95mm to 105mm.

6. A high-imaging-quality lens according to claim 1, characterized in that: The aperture stop (5) is located between the third lens (4) and the fourth lens (6), and the thickness of the aperture stop (5) is 11.5mm to 12.5mm. The distance between the center of the object side surface of the third lens (4) and the object side surface of the aperture stop (5) is 19mm to 21mm.

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