A double-twist lens

Abstract

The present invention relates to a double-reflection lens. The optical system of the lens is composed of five groups of optical lenses, namely a front lens group D, a primary reflector E, a focusing lens group F, a secondary reflector G, and a rear lens group H, which are arranged in sequence along the incident direction of the light path. The lenses with optical power in the front lens group D are, in sequence, a biconvex lens D1, a first cemented group consisting of a biconvex lens D2 and a positive meniscus lens D3, and a second cemented group consisting of a positive meniscus lens D4 and a negative meniscus lens D5. The lenses with optical power in the front lens group D are a third cemented group consisting of a negative meniscus lens F1, a positive meniscus lens F2, and a negative meniscus lens F3. The lenses with optical power in the rear lens group H are a fourth cemented group consisting of a biconvex lens H1 and a positive meniscus lens H2. The double-reflection lens of the present invention reflects and deflects the light path twice. The double-reflection design can greatly reduce the total length of the lens, meeting the requirement of less space usage. The lens has good stability and reliability, high imaging quality, and low distortion.

Description

Technical Field

[0001] The present invention relates to the field of lenses, in particular to a double-bending lens. Background Art

[0002] For a telephoto lens, the longer the focal length, the longer the corresponding detection distance. In order to meet the detection needs of farther targets, the focal length needs to be as long as possible. Since the focal length is too long, the total length of the optical system will be longer, which will cause the lens length to become longer and the space occupied by the entire lens to become larger, which is not conducive to the requirements of miniaturization and lightweight of the entire system, and also limits the application range of the lens, and cannot meet the usage requirements of some specific scenarios. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a double-bend lens, which greatly reduces the total length of the lens, meets the requirement of less space usage, has low distortion and high imaging quality.

[0004] The present invention is implemented by the following scheme: a double-reflection lens, the optical system of which is composed of five groups of optical lenses, namely a front lens group D, a primary reflector E, a focusing lens group F, a secondary reflector G, and a rear lens group H, which are arranged in sequence along the incident direction of the light path; the lenses with optical power in the front lens group D are, in sequence, a biconvex lens D1, a first cemented group consisting of a biconvex lens D2 and a positive meniscus lens D3 in close contact, and a second cemented group consisting of a positive meniscus lens D4 and a negative meniscus lens D5 in close contact; the lenses with optical power in the front lens group D are a third cemented group consisting of a negative meniscus lens F1, a positive meniscus lens F2, and a negative meniscus lens F3 in close contact; and the lenses with optical power in the rear lens group H are a fourth cemented group consisting of a biconvex lens H1 and a positive meniscus lens H2 in close contact.

[0005] Furthermore, the air gap between the biconvex lens D1 and the first cemented group is 38.35 mm, the air gap between the first cemented group and the second cemented group is 16.36 mm; the central air gap between the second cemented group and the primary reflector E is 34.41 mm; the central air gap between the primary reflector E and the third cemented group is 38.59 mm; the central air gap between the third cemented group and the secondary reflector G is 24 mm; and the central air gap between the secondary reflector G and the fourth cemented group is 22 mm.

[0006] Furthermore, the primary reflector E and the secondary reflector G are installed at an angle of 45 degrees relative to the light path so that the light path generates a 90-degree reflection turn after passing through.

[0007] Furthermore, the mechanical structure of the lens includes a front barrel part A, a focusing and turning part B, and a rear group and turning part C; the front lens group D is installed in the front barrel part A, the primary reflective mirror E and the focusing lens group F are installed in the focusing and turning part B, and the secondary reflective mirror G and the rear lens group H are installed in the rear group and turning part C.

[0008] Furthermore, the front barrel part A includes a pressure ring A1, a front lens barrel A2, a pressure ring A3, an adjustment gasket A4, and a pressure ring A5; the focusing and transition part B includes a primary reflector seat B1, a primary reflector flange B2, a connecting flange B3, a focusing barrel B4, a pressure ring B5, a pressure ring B6, a focusing cam B7, a focusing lens seat B8, and a focusing guide pin B9; the rear group and transition part C includes a base plate C1, a secondary reflector seat C2, a secondary reflector flange C3, a pressure ring C4, and a camera interface C5.

[0009] Compared with the prior art, the present invention has the following beneficial effects: the double-reflection lens of the present invention reflects and reflects the light path twice. The double-reflection design can greatly reduce the total length of the lens and meet the requirements of less space usage; it has good stability and reliability, low distortion, and high imaging quality.

[0010] 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

[0011] Figure 1 This is a cross-sectional view of the overall structure of an embodiment of the present invention;

[0012] Figure 2 Schematic diagram of an optical system according to an embodiment of the present invention;

[0013] Figure 3 This is a detailed diagram of the reflector adjustment structure according to an embodiment of the present invention;

[0014] Figure 4 This is the MTF diagram of the optical system according to the embodiment of the present invention;

[0015] Figure 5 This is a point diagram of the optical system according to an embodiment of the present invention;

[0016] Figure 6 This is a distortion diagram of the optical system according to an embodiment of the present invention; DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] like Figures 1 to 6 As shown, a double-reflection lens, the optical system of the lens consists of five groups of optical lenses, namely a front lens group D, a primary reflector E, a focusing lens group F, a secondary reflector G, and a rear lens group H, which are arranged in sequence along the incident direction of the light path; the lenses with optical power in the front lens group D are, in sequence along the incident direction of the light path, a biconvex lens D1, a first cemented group consisting of a biconvex lens D2 and a positive meniscus lens D3 in close contact, and a second cemented group consisting of a positive meniscus lens D4 and a negative meniscus lens D5 in close contact; the lenses with optical power in the front lens group D are a third cemented group consisting of a negative meniscus lens F1, a positive meniscus lens F2, and a negative meniscus lens F3 in close contact, which are arranged in sequence along the incident direction of the light path; and the lenses with optical power in the rear lens group H are a fourth cemented group consisting of a biconvex lens H1 and a positive meniscus lens H2 in close contact, which are arranged in sequence along the incident direction of the light path.

[0020] The lens's primary reflector E and secondary reflector G reflect light twice after it enters the lens. This double-reflection design significantly reduces the overall length of the lens, meeting space requirements. Double-reflection optical lenses offer exceptional spatial flexibility and are particularly well-suited for applications with limited space, such as in polar regions and aerospace applications. They offer unparalleled advantages in military, criminal investigation, aerospace, and other fields.

[0021] In this embodiment, the air gap between the biconvex lens D1 and the first cemented group is 38.35 mm, the air gap between the first cemented group and the second cemented group is 16.36 mm; the central air gap between the second cemented group and the primary reflector E is 34.41 mm; the central air gap between the primary reflector E and the third cemented group is 38.59 mm; the central air gap between the third cemented group and the secondary reflector G is 24 mm; and the central air gap between the secondary reflector G and the fourth cemented group is 22 mm.

[0022] In this embodiment, the primary reflector E and the secondary reflector G are installed at an angle of 45 degrees relative to the light path so that the light path generates a 90-degree reflection turn after passing through.

[0023] The technical indicators achieved by the optical system of this embodiment are as follows:

[0024] The indicators achieved by the above lens are as follows:

[0025] (1) Spectral range: 400-1000nm;

[0026] (2) Focal length: 480mm;

[0027] (3) F-number: 6.5;

[0028] (4) Working distance: 500m~+∞;

[0029] (5) Pixel size: 11μm×11μm

[0030] (6) Number of pixels: 2048 × 2048;

[0031] (7) Optical transfer function: full field MTF>0.2@46lp / mm;

[0032] (8) Maximum distortion: <2%;

[0033] (9) Operating temperature range: -40℃~+60℃;

[0034] (10) Total optical length: ≤280mm;

[0035] (11) White light transmittance: ≥80%;

[0036] (12)Weight: <1.6kg.

[0037] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0038]

[0039] In this embodiment, the mechanical structure of the lens includes a front barrel part A, a focusing and transition part B, and a rear group and transition part C; the front lens group D is installed in the front barrel part A, the primary reflective mirror E and the focusing lens group F are installed in the focusing and transition part B, and the secondary reflective mirror G and the rear lens group H are installed in the rear group and transition part C.

[0040] In this embodiment, the front barrel part A includes a pressure ring A1, a front lens barrel A2, a pressure ring A3, an adjustment gasket A4, and a pressure ring A5; the focusing and transition part B includes a primary reflector seat B1, a primary reflector flange B2, a connecting flange B3, a focusing barrel B4, a pressure ring B5, a pressure ring B6, a focusing cam B7, a focusing lens seat B8, and a focusing guide pin B9; the rear group and transition part C includes a base plate C1, a secondary reflector seat C2, a secondary reflector flange C3, a pressure ring C4, and a camera interface C5.

[0041] The focusing lens seat B8 is located in the focusing barrel B4, and the focusing lens group F is installed on the focusing lens seat B8. The front and rear focusing distance of the focusing lens seat B8 is -0.5mm~+0.3mm, and the moving direction toward the image plane is the positive direction.

[0042] The relative position of the second cemented group formed by the positive meniscus lens D4 and the biconcave lens D5 of the front lens group D in close contact has a great influence on the imaging quality of the lens. Adjustment gaskets A4 of different thicknesses are provided at their assembly to facilitate the adjustment of their front and rear installation positions.

[0043] The primary reflector mount B1 and the secondary reflector mount C2 are respectively provided with adjustment structures I for the primary reflector E and the secondary reflector G. The adjustment structure can be adjusted using screws I1 to adjust the pitch angle of the reflector and thus adjust the imaging quality of the lens; the adjustment structure is tightened using screws I2 to lock the lens in a good state.

[0044] Each lens of the front lens group D is fixed using multiple pressure rings (pressure ring A1, pressure ring A3, pressure ring A5), reducing the problem of insufficient preload force caused by length and improving the tightening effect of the lenses.

[0045] The double-turn optical lens uses a structural design and mechanical compensation method to effectively improve the space utilization of the user unit. The added adjustment mechanism greatly improves the production efficiency of the lens, making the lens more reliable and convenient during the production and debugging process, and effectively improving the stability and reliability of the lens required for this type of use.

[0046] 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.

[0047] 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).

[0048] 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.

[0049] 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.

[0050] 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 double-bend lens, characterized in that: The optical system of the lens consists of five groups of optical lenses, namely a front lens group D, a primary reflector E, a focusing lens group F, a secondary reflector G, and a rear lens group H, which are arranged in sequence along the incident direction of the light path; the lenses with optical power in the front lens group D are, in sequence, a biconvex lens D1, a first cemented group consisting of a biconvex lens D2 and a positive meniscus lens D3 in close contact, and a second cemented group consisting of a positive meniscus lens D4 and a negative meniscus lens D5 in close contact; the lenses with optical power in the front lens group D are a third cemented group consisting of a negative meniscus lens F1, a positive meniscus lens F2, and a negative meniscus lens F3 in close contact; and the lenses with optical power in the rear lens group H are a fourth cemented group consisting of a biconvex lens H1 and a positive meniscus lens H2 in close contact.

2. The double-bending lens according to claim 1, wherein: The air gap between the biconvex lens D1 and the first cemented group is 38.35 mm, the air gap between the first cemented group and the second cemented group is 16.36 mm; the central air gap between the second cemented group and the primary reflector E is 34.41 mm; the central air gap between the primary reflector E and the third cemented group is 38.59 mm; the central air gap between the third cemented group and the secondary reflector G is 24 mm; and the central air gap between the secondary reflector G and the fourth cemented group is 22 mm.

3. The double-bending lens according to claim 1, wherein: The primary reflector E and the secondary reflector G are installed at an angle of 45 degrees relative to the light path so that the light path generates a 90-degree reflection turn after passing through.

4. The double-bending lens according to claim 1, wherein: The mechanical structure of the lens includes a front barrel part A, a focusing and turning part B, and a rear group and turning part C; the front lens group D is installed in the front barrel part A, the primary reflector E and the focusing lens group F are installed in the focusing and turning part B, and the secondary reflector G and the rear lens group H are installed in the rear group and turning part C.

5. The double-bending lens according to claim 4, wherein: The front barrel part A includes a pressure ring A1, a front lens barrel A2, a pressure ring A3, an adjustment gasket A4, and a pressure ring A5; the focusing and transition part B includes a primary reflector seat B1, a primary reflector flange B2, a connecting flange B3, a focusing barrel B4, a pressure ring B5, a pressure ring B6, a focusing cam B7, a focusing lens seat B8, and a focusing guide pin B9; the rear group and transition part C includes a base plate C1, a secondary reflector seat C2, a secondary reflector flange C3, a pressure ring C4, and a camera interface C5.

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