A zoom lens

Abstract

The present invention relates to a zoom lens. The optical system of the lens comprises a front lens group E, a variator lens group F, a compensator lens group G, and a rear lens group H, which are sequentially arranged along an incident light path. The front lens group E comprises a positive meniscus lens E1, a first cemented group consisting of a positive meniscus lens E2 and a biconvex lens E3 in close contact, and a positive meniscus lens E4. The variator lens group F comprises a negative meniscus lens F1, a second cemented group consisting of a biconcave lens F2 and a positive meniscus lens F3 in close contact, and a biconcave lens F4. The compensator lens group G comprises a biconvex lens G1, a biconvex lens G2, and a positive meniscus lens G3. The rear lens group H comprises a biconvex lens H1, a positive meniscus lens H2, a third cemented group consisting of a biconcave lens H3 and a biconvex lens H4 in close contact, a positive meniscus lens H5, a negative meniscus lens H6, and a positive meniscus lens H7.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technology, and in particular to a zoom lens. Background Art

[0002] Zoom optical lenses offer the ability to operate in a variety of environments, making them particularly suitable for applications with limited space (such as polar regions and aerospace applications). They offer unparalleled advantages in military, criminal investigation, and aerospace applications. Zoom lenses utilize a cam focusing mechanism, making them more reliable and convenient during production and commissioning, effectively improving the stability and reliability of lenses used in these applications. Consequently, the overall system structure is simpler than that of standard camera lenses. Summary of the Invention

[0003] In view of this, an object of the present invention is to provide a zoom lens with small distortion and good object resolution, which can meet the usage requirements of the 30mm-320mm focal length range.

[0004] The present invention is implemented by the following scheme: a zoom lens, the optical system of which is composed of a front lens group E, a variator lens group F, a compensator lens group G, and a rear lens group H, which are arranged in sequence along the incident light path; the lenses with optical power in the front lens group E along the incident light path are, in sequence, a positive meniscus lens E1, a first cemented group consisting of a positive meniscus lens E2 and a biconvex lens E3, and a positive meniscus lens E4; the lenses with optical power in the variator lens group F along the incident light path are, in sequence, a negative meniscus lens F1, a first cemented group consisting of a positive meniscus lens E2 and a biconvex lens E3, and a positive meniscus lens E4; The second cemented group is composed of a concave lens F2 and a positive meniscus lens F3 in close contact, and the biconcave lens F4; the lenses with optical power along the incident light path of the compensation lens group G are, in order, a biconvex lens G1, a biconvex lens G2, and a positive meniscus lens G3; the lenses with optical power along the incident light path of the rear lens group H are, in order, a biconvex lens H1, a positive meniscus lens H2, a third cemented group composed of a biconcave lens H3 and a biconvex lens H4 in close contact, a positive meniscus lens H5, a negative meniscus lens H6, and a positive meniscus lens H7.

[0005] Furthermore, the air gap between the positive meniscus lens E1 in the front lens group E and the first cemented group is 1.76 mm, and the air gap between the first cemented group and the positive meniscus lens E4 is 3.7 mm.

[0006] Furthermore, the air gap between the negative meniscus lens F1 and the second cemented group in the zoom lens group F is 4.31 mm, and the air gap between the second cemented group and the biconcave lens F4 is 1.94 mm.

[0007] Furthermore, the air gap between the biconvex lens G1 and the biconvex lens G2 in the compensation lens group G is 0.1 mm, and the air gap between the biconvex lens G2 and the positive crescent lens G3 is 0.1 mm.

[0008] Furthermore, the air gap between the biconvex lens H1 and the positive meniscus lens H2 in the rear lens group H is 0.43 mm, the air gap between the positive meniscus lens H2 and the third cemented group is 3.58 mm, the air gap between the third cemented group and the positive meniscus lens H5 is 6.08 mm, the air gap between the positive meniscus lens H5 and the negative meniscus lens H6 is 0.82 mm, and the air gap between the negative meniscus lens H6 and the positive meniscus lens H7 is 13.64 mm.

[0009] Furthermore, the mechanical structure of the lens includes a front barrel part A, a magnification component part B, a light barrier component part C and a rear component part D arranged in sequence along the incident light path, the front lens group E is installed in the middle of the front barrel part A, the magnification lens group F and the compensation lens group G are installed in the middle of the magnification component part B, and the rear lens group H is installed in the middle of the rear component part D.

[0010] Furthermore, the front barrel part A includes a pressure ring A1, a pressure ring A2, a gasket A3, a pressure ring A4, a lens mount A5, a guide pin A6, a gasket A7, a cam A8, a pressure ring A9, and a lens barrel A10; the zoom component part B includes a pressure ring B1, a lens mount B2, a slide B3, a cam B4, a slide B5, a lens mount B6, a spacer B7, a spacer B8, and a pressure ring B9; the light barrier component part C includes a light barrier piece C1, a moving ring C2, a bracket C3, a guide pin C4, a cam C5, and a pressure ring C6; the rear group component part D includes a pressure ring D1, a spacer D2, a spacer D3, a lens mount D4, a spacer D5, and a pressure ring D6.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) Small distortion, good target resolution, high uniformity of image illumination, on the one hand, it can easily identify targets at a long distance and a large range, on the other hand, it can magnify and observe targets at a short distance and a small range, and has the characteristics of continuous focus, continuous imaging and clearness during the zoom process; it can achieve the use of 30mm-320mm focal length and clear imaging, and is more suitable for use in places where the focal length needs to be changed, which greatly facilitates the user's use needs;

[0013] (2) Each lens is installed using multiple washers, reducing the problem of large discrepancies between the lens air gap and the design value caused by processing size errors, thereby improving the accuracy of the lens installation position;

[0014] (3) The amount of light entering can be controlled by adjusting the focusing light bar component to meet the requirements of use in different lighting environments.

[0015] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments and related drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a general assembly diagram of an embodiment of the present invention;

[0017] Figure 2 Schematic diagram of an optical system according to an embodiment of the present invention;

[0018] Figure 3 This is a short-focus MTF diagram of the optical system according to an embodiment of the present invention;

[0019] Figure 4 This is the telephoto MTF diagram of the optical system according to an embodiment of the present invention;

[0020] Figure 5 This is a short-focus distortion diagram of the optical system according to an embodiment of the present invention;

[0021] Figure 6 This is a telephoto distortion diagram of the optical system according to an embodiment of the present invention;

[0022] Figure 7 This is a short-focus relative illumination diagram of the optical system according to an embodiment of the present invention;

[0023] Figure 8 This is a telephoto relative illumination diagram of the optical system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] like Figures 1 to 8As shown, a zoom lens, the optical system of the lens is composed of a front lens group E, a variator lens group F, a compensator lens group G, and a rear lens group H arranged in sequence along the incident light path; the lenses with optical power along the incident light path of the front lens group E are, in sequence, a positive meniscus lens E1, a first cemented group consisting of a positive meniscus lens E2 and a biconvex lens E3, and a positive meniscus lens E4; the lenses with optical power along the incident light path of the variator lens group F are, in sequence, a negative meniscus lens F1, a biconcave lens F 2 and a positive meniscus lens F3 are closely bonded, and a biconcave lens F4 is formed; the lenses having optical power along the incident light path of the compensation lens group G are, in order, a biconvex lens G1, a biconvex lens G2, and a positive meniscus lens G3; the lenses having optical power along the incident light path of the rear lens group H are, in order, a biconvex lens H1, a positive meniscus lens H2, a third cemented group consisting of a biconcave lens H3 and a biconvex lens H4, a positive meniscus lens H5, a negative meniscus lens H6, and a positive meniscus lens H7.

[0027] In this embodiment, the air gap between the positive meniscus lens E1 and the first cemented group in the front lens group E is 1.76 mm, and the air gap between the first cemented group and the positive meniscus lens E4 is 3.7 mm.

[0028] In this embodiment, the air gap between the negative meniscus lens F1 and the second cemented group in the zoom lens group F is 4.31 mm, and the air gap between the second cemented group and the biconcave lens F4 is 1.94 mm.

[0029] In this embodiment, the air gap between the biconvex lens G1 and the biconvex lens G2 in the compensation lens group G is 0.1 mm, and the air gap between the biconvex lens G2 and the positive meniscus lens G3 is 0.1 mm.

[0030] In this embodiment, the air gap between the biconvex lens H1 and the positive meniscus lens H2 in the rear lens group H is 0.43 mm, the air gap between the positive meniscus lens H2 and the third cemented lens group is 3.58 mm, the air gap between the third cemented lens group and the positive meniscus lens H5 is 6.08 mm, the air gap between the positive meniscus lens H5 and the negative meniscus lens H6 is 0.82 mm, and the air gap between the negative meniscus lens H6 and the positive meniscus lens H7 is 13.64 mm.

[0031] The zoom lens group F and the compensating lens group G are linked by a cam, allowing the lens focal length to vary from 30mm to 320mm, meeting the needs of different focal length ranges. The zoom lens group F can move back and forth a distance of 25.86mm, while the compensating lens group G can move back and forth a distance of 25.05mm. When the lens is in the short focus position (focal length of 30mm), the air gap between the positive meniscus lens E4 and the negative meniscus lens F1 is 1.09mm, the air gap between the biconcave lens F4 and the biconvex lens G1 is 53.48mm, and the air gap between the positive meniscus lens G3 and the biconvex lens H1 is 2.58mm.

[0032] In the present invention, a gap is reserved at the front end of the front lens mount A5 of the front barrel portion A to allow space for deformation and expansion of parts during high and low temperature use, thereby preventing the movement mechanism from getting stuck; the front and rear focusing distances of the front lens group E are -0.3mm to +0.2mm, with the direction of movement toward the image plane being the positive direction.

[0033] In this embodiment, the mechanical structure of the lens includes a front barrel part A, a magnification component part B, a light barrier component part C and a rear component part D arranged in sequence along the incident light path, the front lens group E is installed in the middle of the front barrel part A, the magnification lens group F and the compensation lens group G are installed in the middle of the magnification component part B, and the rear lens group H is installed in the middle of the rear component part D.

[0034] In this embodiment, the front barrel part A includes a pressure ring A1, a pressure ring A2, a gasket A3, a pressure ring A4, a lens mount A5, a guide pin A6, a gasket A7, a cam A8, a pressure ring A9, and a lens barrel A10; the zoom component part B includes a pressure ring B1, a lens mount B2, a slide B3, a cam B4, a slide B5, a lens mount B6, a spacer B7, a spacer B8, and a pressure ring B9; the light barrier component part C includes a light barrier piece C1, a moving ring C2, a bracket C3, a guide pin C4, a cam C5, and a pressure ring C6; the rear group component part D includes a pressure ring D1, a spacer D2, a spacer D3, a lens mount D4, a spacer D5, and a pressure ring D6.

[0035] The lens of the present invention is designed with a light barrier component part C, and the amount of light entering can be controlled by focusing the light barrier component, which can meet the use requirements in different lighting environments.

[0036] The zoom lens of this invention can achieve sharp images in the 30mm-320mm focal length range, making it particularly suitable for applications requiring variable focal lengths, greatly facilitating user needs. To minimize difficulties encountered during lens production and commissioning, particularly with regard to adjustment of the front barrel section A, the design utilizes multiple washers (washer A3 and washer A7) for each lens element. This reduces the potential for significant discrepancies between the lens air gap and the designed value due to machining dimensional errors, thereby improving lens installation accuracy.

[0037] The indicators achieved by the above lens are as follows:

[0038] 1. Spectral range: 450-700nm;

[0039] 2. Focal length: 30mm-320mm;

[0040] 3. F number: ≤F6@f320mm, ≤F5@f30mm;

[0041] 4. Working distance: 500m~+∞;

[0042] 5. Pixel size: 17μm×11μm

[0043] 6. Number of pixels: 1000×1000;

[0044] 7. Maximum distortion: <2%;

[0045] 8. Operating temperature range: -40℃~+60℃;

[0046] 9. Total optical length: ≤163.4mm;

[0047] 10. Average transmittance: ≥0.7@450nm~700nm;

[0048] 11. Weight: <3kg;

[0049] 12. The distance between the camera mounting base and the photosensitive chip is 12.5mm±0.02mm;

[0050] 14, ƒ30, ƒ175, ƒ320, forward and reverse zoom, the MTF measured values ​​should meet the indicators in Table 1.

[0051] Table 1 Image quality requirements for visible light zoom lenses

[0052]

[0053] To achieve the above design parameters, the specific parameters of the optical system of this embodiment are shown in Table 2:

[0054] Table 2 Data of each lens in the optical system (unit: mm)

[0055]

[0056] Figure 3 This is the short-focus MTF diagram of the optical system of the present invention. At a frequency of 30 lp / mm, the short-focus 0 field of view transfer function is greater than 0.8, and the 0.7 field of view transfer function is greater than 0.58, indicating that the system has good target resolution capability; Figure 4This is the telephoto MTF diagram of the optical system of the present invention. The telephoto 0 field of view transfer function is greater than 0.8, and the 0.7 field of view transfer function is greater than 0.51, indicating that the system has good target resolution capability; Figure 5 This is the short-focus distortion diagram of the optical system of the present invention. The short-focus distortion is less than 2%, indicating that the system has small distortion and good target resolution capability. Figure 6 This is the telephoto distortion diagram of the optical system of the present invention. The telephoto distortion is less than 2%, indicating that the system has small distortion and good target resolution capability. Figure 7 This is the short-focus relative illumination diagram of the optical system of the present invention. The short-focus image plane illumination uniformity is greater than 85%;

[0057] Figure 8 This is the relative illumination diagram of the optical system at long focus of the present invention. The illumination uniformity of the image plane at long focus is greater than 85%.

[0058] Unless otherwise stated, for any of the technical solutions disclosed in the present invention, if a numerical range is disclosed, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely a numerical range that is representative or has a more obvious technical effect among many feasible numerical values. Due to the large number of numerical values, it is impossible to enumerate them exhaustively. Therefore, the present invention discloses some numerical values ​​to illustrate the technical solutions of the present invention. Moreover, the numerical values ​​listed above should not be construed as limiting the scope of protection of the present invention.

[0059] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by integral molding using a casting process) (except where it is obviously not possible to use an integrated molding process).

[0060] In addition, unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes include states or shapes that are approximate, similar, or close thereto.

[0061] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other manner. Any person skilled in the art may utilize the above-disclosed technical content to modify or modify the present invention into equivalent embodiments. However, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical content of the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.

Claims

1. A zoom lens, characterized in that: The optical system of the lens is composed of a front lens group E, a zoom lens group F, a compensation lens group G, and a rear lens group H arranged in sequence along the incident light path; the lens with optical power along the incident light path of the front lens group E is composed of a positive meniscus lens E1, a first cemented group composed of a positive meniscus lens E2 and a biconvex lens E3, and a positive meniscus lens E4; the lens with optical power along the incident light path of the zoom lens group F is composed of a negative meniscus lens F1, a biconcave lens F2 and a positive meniscus lens The lens group G having optical power along the incident light path is composed of a biconvex lens G1, a biconvex lens G2, and a positive meniscus lens G3; the lens group H having optical power along the incident light path is composed of a biconvex lens H1, a positive meniscus lens H2, a third cemented group consisting of a biconcave lens H3 and a biconvex lens H4 closely bonded, a positive meniscus lens H5, a negative meniscus lens H6, and a positive meniscus lens H7.

2. The zoom lens according to claim 1, wherein: The air gap between the positive meniscus lens E1 and the first cemented group in the front lens group E is 1.76 mm, and the air gap between the first cemented group and the positive meniscus lens E4 is 3.7 mm.

3. The zoom lens according to claim 1, wherein: The air gap between the negative meniscus lens F1 and the second cemented group in the zoom lens group F is 4.31 mm, and the air gap between the second cemented group and the biconcave lens F4 is 1.94 mm.

4. The zoom lens according to claim 1, wherein: The air gap between the biconvex lens G1 and the biconvex lens G2 in the compensation lens group G is 0.1 mm, and the air gap between the biconvex lens G2 and the positive crescent lens G3 is 0.1 mm.

5. The zoom lens according to claim 1, wherein: In the rear lens group H, the air gap between the biconvex lens H1 and the positive meniscus lens H2 is 0.43mm, the air gap between the positive meniscus lens H2 and the third cemented group is 3.58mm, the air gap between the third cemented group and the positive meniscus lens H5 is 6.08mm, the air gap between the positive meniscus lens H5 and the negative meniscus lens H6 is 0.82mm, and the air gap between the negative meniscus lens H6 and the positive meniscus lens H7 is 13.64mm.

6. The zoom lens according to claim 1, wherein: The mechanical structure of the lens includes a front barrel part A, a zoom component part B, a light barrier component part C and a rear component part D arranged in sequence along the incident light path, the front lens group E is installed in the middle of the front barrel part A, the zoom lens group F and the compensation lens group G are installed in the middle of the zoom component part B, and the rear lens group H is installed in the middle of the rear component part D.

7. The zoom lens according to claim 6, wherein: The front barrel part A includes a pressure ring A1, a pressure ring A2, a gasket A3, a pressure ring A4, a lens mount A5, a guide pin A6, a gasket A7, a cam A8, a pressure ring A9, and a lens barrel A10; the zoom component part B includes a pressure ring B1, a lens mount B2, a slide B3, a cam B4, a slide B5, a lens mount B6, a spacer B7, a spacer B8, and a pressure ring B9; the light barrier component part C includes a light barrier piece C1, a moving ring C2, a bracket C3, a guide pin C4, a cam C5, and a pressure ring C6; the rear group component part D includes a pressure ring D1, a spacer D2, a spacer D3, a lens mount D4, a spacer D5, and a pressure ring D6.

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