Megapixel day and night co-focus imaging lens and electronic devices

Abstract

The present invention relates to the technical field of imaging lenses, and discloses a tens of millions of pixel day-night confocal imaging lens and an electronic device. The imaging lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in sequence from the object side to the image side, an aperture stop disposed between the second lens and the third lens, and an imaging surface on the image side of the ninth lens; the focal length relationships of the first lens to the ninth lens are as follows: -0.7 < F1 / F < -0.2; 0.2 < F | 2 / F < 0.8; 0.2 < F3 / F < 0.8; -0.8 < F4 / F < -0.4; 0.2 < F5 / F < 0.8; -0.9 < F6 / F < -0.5; -0.8 < F7 / F < -0.2; 0.2 < F8 / F < 0.8; 1 < F9 / F < 2. For the imaging lens and the electronic device of the present invention, the lens can achieve a high resolution of tens of millions of pixels, can be adapted to a chip with a 1.4um pixel size, is applicable to a 1 / 1.8-inch large target surface chip, improves the sensitivity and clarity of the image, especially under low light conditions, has stronger spectral transmission ability and spectral correction ability, and is applicable to occasions that require high resolution and high sensitivity monitoring.

Description

Technical Field

[0001] This invention relates to the field of imaging lens technology, and in particular to a megapixel day and night confocal imaging lens and electronic device. Background Technology

[0002] The statements in this section are merely to provide background information related to the disclosure of this invention and do not necessarily constitute prior art.

[0003] A megapixel day / night confocal imaging lens is a lens capable of maintaining clear imaging under various lighting conditions, typically used in surveillance, industrial inspection, and other fields. Its main functions and features include: support for megapixel high-definition imaging; dual-use capability, providing color images during the day and monochrome images at night; built-in autofocus for easy operation; fog-penetrating capability for clear imaging in foggy environments; automatic temperature compensation to adapt to environments with large temperature differences; and military-grade standards, capable of operating in extreme environments ranging from -40℃ to 70℃. These megapixel day / night confocal imaging lenses, through optical design and functional integration, provide high-quality imaging under various lighting conditions, making them suitable for applications requiring all-weather monitoring.

[0004] In specific application environments, multi-megapixel day and night confocal imaging lenses are widely used in practical monitoring scenarios such as video surveillance, perimeter security, personnel positioning, industrial monitoring, traffic monitoring, commercial monitoring, and environmental monitoring, especially in scenarios such as elderly care, child care, infant care, and medical care.

[0005] In the aforementioned monitoring scenarios, current megapixel day and night confocal imaging lenses suffer from problems such as small target area, large chromatic aberration, low illumination, low resolution, and high cost. Lenses that are compatible with 1 / 1.8-inch chips mostly have a resolution of 2.74µm, which is gradually becoming insufficient to meet the needs of the monitoring market. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a lens with a cutoff frequency of 300 line pairs / mm across the entire field of view, corresponding to a modulation transfer function value better than 0.3. This lens can achieve a resolution of tens of millions of pixels and is compatible with chips with 1.4µm pixels, which helps improve image sensitivity and clarity, especially under low light conditions. It is suitable for 1 / 1.8-inch large target surface chips, has stronger spectral transmission and spectral correction capabilities, and is suitable for tens of millions of pixel day and night confocal imaging lenses and electronic devices for occasions requiring high resolution and high sensitivity monitoring.

[0007] The technical solution adopted by the present invention is as follows: a tens of millions of pixel day-night co-focus imaging lens, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in sequence from the object side to the image side, and an aperture stop disposed between the third lens and the fourth lens; and an imaging surface on the image side of the ninth lens; wherein: the focal lengths of the first lens to the ninth lens satisfy the following focal length relationship formula: -0.7 < F1 / F < -0.2; 0.2 < F2 / F < 0.8; 0.2 < F3 / F < 0.8; -0.8 < F4 / F < -0.4; 0.2 < F5 / F < 0.8; -0.9 < F6 / F < -0.5; -0.8 < F7 / F < -0.2; 0.2 < F8 / F < 0.8; 1 < F9 / F < 2; where F is the total focal length F, F1 is the focal length of the first lens, F2 is the focal length of the second lens, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, F5 is the focal length of the fifth lens, F6 is the focal length of the sixth lens, F7 is the focal length of the seventh lens, F8 is the focal length of the eighth lens, and F9 is the focal length of the ninth lens.

[0008] In at least one embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens are all spherical mirrors.

[0009] In at least one embodiment, the first lens and the second lens, the fifth lens and the sixth lens, and the seventh lens and the eighth lens are respectively integrated cemented lenses, and at the same time, an air gap is provided between the second lens and the third lens, between the third lens and the aperture stop, between the aperture stop and the fourth lens, between the fourth lens and the fifth lens, between the sixth lens and the seventh lens, between the seventh lens and the eighth lens, and between the ninth lens and the imaging surface.

[0010] In at least one embodiment, the relationship between the optical total length TTL of the imaging lens and the maximum image height IH corresponding to the maximum field angle is: 5 ≤ TTL / IH ≤ 7.

[0011] In at least one embodiment, the relationship between the back focal length BFL of the imaging lens and the total focal length F is: 0.5 ≤ BFL / F ≤ 1.

[0012] In at least one embodiment, the first lens is a negative meniscus lens, the second lens is a positive biconvex lens, the third lens is a positive biconvex lens, the fourth lens is a negative meniscus lens, the fifth lens is a positive biconvex lens, the sixth lens is a negative meniscus lens, the seventh lens is a negative meniscus lens, the eighth lens is a positive biconvex lens, and the ninth lens is a positive biconvex lens.

[0013] The electronic device has the aforementioned megapixel day and night confocal imaging lens.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. A first lens, second lens, third lens, aperture stop, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, and ninth lens are arranged sequentially along the optical axis. The effective focal length F of the optical system composed of these lenses satisfies the focal length relationship of the formula, making it compatible with 1.4µm pixel chips. This helps improve image sensitivity and clarity, especially under low-light conditions. It is suitable for 1 / 1.8-inch large-area chips, thereby improving the resolution of multi-megapixel day / night confocal imaging lenses and electronic devices, providing very clear images, capturing more details, and at a lower cost.

[0016] 2. The first lens is designed as a biconcave lens with negative optical power, the second lens as a biconvex lens with positive optical power, the third lens as a biconvex lens with positive optical power, the fourth lens as a biconcave lens with negative optical power, the fifth lens as a biconvex lens with positive optical power, the sixth lens as a biconcave lens with negative optical power, the seventh lens as a biconcave lens with negative optical power, the eighth lens as a biconvex lens with positive optical power, and the ninth lens as a biconvex lens with positive optical power. All of the above lenses, from the first to the ninth, are spherical lenses, which facilitates processing and testing.

[0017] The present invention relates to a megapixel day and night confocal imaging lens and electronic device, which has a cutoff frequency of 300 line pairs / mm across the entire field of view and a corresponding modulation transfer function value better than 0.3. The imaging lens can achieve a high resolution of 10 million pixels and is compatible with chips with 1.4µm pixels, which helps to improve the sensitivity and clarity of images, especially under low light conditions. It is suitable for 1 / 1.8-inch large target surface chips, has stronger spectral transmission and spectral correction capabilities, and is suitable for occasions requiring high resolution and high sensitivity monitoring. It has good practical and economic value. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the optical structure of a high-resolution 10-megapixel day-night confocal imaging lens according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 The modulation transfer function curve of the embodiment is shown, where the horizontal axis is the spatial frequency in period / mm and the vertical axis is the OTF magnitude.

[0020] Figure 3 yes Figure 1The distortion curve of the embodiment, where the horizontal axis is percentage and the vertical axis is field of view angle;

[0021] Figure 4 yes Figure 1 The relative illuminance curve of the embodiment, where the horizontal axis is the field of view in millimeters and the vertical axis is the relative illuminance;

[0022] Wherein: 1-first lens, 2-second lens, 3-third lens, 4-fourth lens, 5-fifth lens, 6-sixth lens, 7-seventh lens, 8-eighth lens, 9-ninth lens, 10-aperture stop, 11-image plane. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the combination or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, in the description of the embodiments of this invention, the positional relationships of devices such as "upper," "lower," "front," "rear," "left," and "right" in all figures are based on… Figure 1 As the standard.

[0025] like Figure 1 As shown, a multi-megapixel day-night confocal imaging lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, and a ninth lens 9 arranged sequentially from the object side to the image side, and an aperture stop 10 disposed between the second lens 2 and the third lens 3; and an imaging plane 11 located on the image side of the ninth lens 9; wherein the focal lengths of the first lens 1 to the ninth lens 9 satisfy the following focal length relationship:

[0026] -0.7 <F1 / F<-0.2;

[0027] 0.2 <F2 / F<0.8;

[0028] 0.2 <F3 / F<0.8;

[0029] -0.8 <F4 / F<-0.4;

[0030] 0.2 <F5 / F<0.8;

[0031] -0.9 <F6 / F<-0.5;

[0032] -0.8 <F7 / F<-0.2;

[0033] 0.2 <F8 / F<0.8;

[0034] 1 <F9 / F<2;

[0035] In the formula, F is the total focal length F, F1 is the focal length of the first lens, F2 is the focal length of the second lens, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, F5 is the focal length of the fifth lens, F6 is the focal length of the sixth lens, F7 is the focal length of the seventh lens, F8 is the focal length of the eighth lens, and F9 is the focal length of the ninth lens.

[0036] In at least one embodiment, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9 are all spherical mirrors, which facilitates processing and testing.

[0037] In at least one embodiment, the first lens 1 and the second lens 2, the fifth lens 5 and the sixth lens 6, and the seventh lens 7 and the eighth lens 8 are all integral cemented lenses. Meanwhile, air gaps are set between the second lens 2 and the third lens 3, between the third lens 3 and the aperture stop 10, between the aperture stop 10 and the fourth lens 4, between the fourth lens 4 and the fifth lens 5, between the sixth lens 6 and the seventh lens 7, between the seventh lens 7 and the eighth lens 8, and between the ninth lens 9 and the imaging plane 11. That is, the first lens 1 and the second lens 2 are independent integral cemented lenses, the fifth lens 5 and the sixth lens 6 are independent integral cemented lenses, and the seventh lens 7 and the eighth lens 8 are independent integral cemented lenses. Each set of integral cemented lenses can be installed and disassembled independently during installation. However, the cemented lenses bonded together are installed and disassembled as a whole. Except for the bonded lens sets, the other lenses are arranged with air gaps between them.

[0038] In at least one embodiment, the relationship between the total optical length TTL of the imaging lens and the maximum image height IH corresponding to the maximum field of view is: 5≤TTL / IH≤7.

[0039] In at least one embodiment, the relationship between the back focal length BFL and the total focal length F of the imaging lens is: 0.5≤BFL / F≤1.

[0040] In at least one embodiment, the first lens 1 is a biconcave lens with negative optical power, the second lens 2 is a biconvex lens with positive optical power, the third lens 3 is a biconvex lens with positive optical power, the fourth lens 4 is a biconcave lens with negative optical power, the fifth lens 5 is a biconvex lens with positive optical power, the sixth lens 6 is a biconcave lens with negative optical power, the seventh lens 7 is a biconcave lens with negative optical power, the eighth lens 8 is a biconvex lens with positive optical power, and the ninth lens 9 is a biconvex lens with positive optical power.

[0041] In at least one embodiment, the air gap between the second lens 2 and the third lens 3 is between 0.1 mm and 0.5 mm, the air gap between the third lens 3 and the aperture stop 10 is between 0.1 mm and 0.5 mm, the air gap between the aperture stop 10 and the fourth lens 4 is between 0.4 mm and 1 mm, the air gap between the fourth lens 4 and the fifth lens 5 is between 0.4 mm and 1 mm, the air gap between the sixth lens 6 and the seventh lens 7 is between 0.1 mm and 0.5 mm, the air gap between the eighth lens 8 and the ninth lens 9 is between 0.1 mm and 0.5 mm, and the air gap between the ninth lens 9 and the imaging plane 11 is between 6 mm and 12 mm.

[0042] In one embodiment, the air gap between the second lens 2 and the third lens 3 is 0.1 mm, the air gap between the third lens 3 and the aperture stop 10 is 0.4 mm, the air gap between the aperture stop 10 and the fourth lens 4 is 0.6 mm, the air gap between the fourth lens 4 and the fifth lens 5 is 0.6 mm, the air gap between the sixth lens 6 and the seventh lens 7 is 0.1 mm, the air gap between the eighth lens 8 and the ninth lens 9 is 0.1 mm, and the air gap between the ninth lens 9 and the imaging plane 11 is 9.3 mm. In this embodiment, the high-resolution 10-megapixel day / night confocal imaging lens has an effective focal length F of 12.5 mm, a relative numerical aperture F / 2.4, a full field of view of 39.2°, a diagonal dimension of the imaging plane of 9 mm, and a total optical length of 28 mm (the distance from the first lens 1 to the ninth lens 9). The operating wavelength is 400-900 nm. The optical parameters of each lens are shown in Table 1 below.

[0043] Table 1. Lens optical parameters in the embodiments

[0044] Face number radius thickness Refractive index Abbe number 1 -12.1 3 1.92 20.9 2 9.1 3.0 1.75 51 3 -12.6 0.1 / / 4 10.6 1.8 2.10 17.0 5 -47.1 0.4 / / 6 (Aperture) unlimited 0.6 / / 7 -27.0 0.8 1.61 44.1 8 6.2 0.6 / / 9 6.9 1.7 1.88 40.8 10 -737.2 1.0 1.85 23.8 11 9.4 1.0 / / 12 -12.4 0.8 1.99 16.5 13 8.7 2.5 1.59 68.3 14 -8.5 0.1 / / 15 29.6 1.4 2.10 17.0 16 -43.1 7.6 / / 17 unlimited 9.3 / / Image unlimited / / /

[0045] like Figure 2 As shown, Figure 1The high-resolution 10-megapixel day and night confocal imaging lens shown has a cutoff frequency of 300 line pairs / mm across the entire field of view, with a corresponding modulation transfer function value better than 0.3. The imaging lens can achieve 10 megapixels, can be adapted to 1.4µm pixel chips, and is suitable for 1 / 1.8-inch large target surface chips. Moreover, the modulation transfer function curves of each field of view are relatively concentrated, indicating that the high-resolution 10-megapixel day and night confocal imaging lens can achieve high-precision target detection.

[0046] like Figure 3 As shown, Figure 1 The high-resolution, 10-megapixel day-night confocal imaging lens shown exhibits a distortion value of less than 2% across the entire field of view, achieving high fidelity in visible-infrared imaging.

[0047] like Figure 4 As shown, Figure 1 The high-resolution, 10-megapixel day-night confocal imaging lens shown has a relative illumination value of over 80% across the entire field of view, thus avoiding vignetting.

[0048] Electronic devices equipped with the aforementioned megapixel day / night confocal imaging lens are applicable to, but are not limited to, medical diagnostics, microscopy systems, document imaging and acquisition, industrial assembly line imaging and acquisition, fingerprint and palmprint imaging and acquisition, desktop image capture, portrait and iris recognition, high-speed license plate capture, and outdoor monitoring in fields such as medical care, banking, industry, security, transportation, and monitoring. This megapixel day / night confocal imaging lens features high resolution, providing clear and detailed images; it also offers a high frame rate to ensure smooth dynamic images, high color reproduction for lifelike color reproduction, and achieves uncompressed and interpolated operation to guarantee image authenticity; and it offers multiple triggering and I / O options to adapt to different shooting needs.

[0049] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A 10-megapixel day-night confocal imaging lens, characterized in that, include: The first lens (1), second lens (2), third lens (3), fourth lens (4), fifth lens (5), sixth lens (6), seventh lens (7), eighth lens (8), and ninth lens (9) are arranged sequentially from object side to image side. An aperture stop (10) is set between the third lens (3) and the fourth lens (4); and The imaging plane (11) is located on the image side of the ninth lens (9). Wherein: the focal lengths of the first lens (1) to the ninth lens (9) satisfy the following focal length relationship: -0.7 <F1 / F<-0.2; 0.2 <F2 / F<0.8; 0.2 <F3 / F<0.8; -0.8 <F4 / F<-0.4; 0.2 <F5 / F<0.8; -0.9 <F6 / F<-0.5; -0.8 <F7 / F<-0.2; 0.2 <F8 / F<0.8; 1 <F9 / F<2; In the formula, F is the total focal length F, F1 is the focal length of the first lens, F2 is the focal length of the second lens, F3 is the focal length of the third lens, F4 is the focal length of the fourth lens, F5 is the focal length of the fifth lens, F6 is the focal length of the sixth lens, F7 is the focal length of the seventh lens, F8 is the focal length of the eighth lens, and F9 is the focal length of the ninth lens. The lens contains nine lenses with optical power. The first lens (1) is a biconcave lens with negative optical power, the second lens (2) is a biconvex lens with positive optical power, the third lens (3) is a biconvex lens with positive optical power, the fourth lens (4) is a biconcave lens with negative optical power, the fifth lens (5) is a biconvex lens with positive optical power, the sixth lens (6) is a biconcave lens with negative optical power, the seventh lens (7) is a biconcave lens with negative optical power, the eighth lens (8) is a biconvex lens with positive optical power, and the ninth lens (9) is a biconvex lens with positive optical power.

2. The megapixel day / night confocal imaging lens according to claim 1, characterized in that: The first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), and the ninth lens (9) are all spherical mirrors.

3. The megapixel day / night confocal imaging lens according to claim 2, characterized in that: The first lens (1), the second lens (2), the fifth lens (5), the sixth lens (6), the seventh lens (7), and the eighth lens (8) are all integral cemented lenses. At the same time, air gaps are set between the second lens (2) and the third lens (3), between the third lens (3) and the aperture stop (10), between the aperture stop (10) and the fourth lens (4), between the fourth lens (4) and the fifth lens (5), between the sixth lens (6) and the seventh lens (7), between the seventh lens (7) and the eighth lens (8), and between the ninth lens (9) and the imaging plane (11).

4. The megapixel day / night confocal imaging lens according to claim 3, characterized in that: The relationship between the total optical length TTL of the imaging lens and the maximum image height IH corresponding to the maximum field of view is: 5≤TTL / IH≤7.

5. The megapixel day / night confocal imaging lens according to claim 4, characterized in that: The relationship between the back focal length BFL and the total focal length F of the imaging lens is: 0.5≤BFL / F≤1.

6. The megapixel day / night confocal imaging lens according to claim 1, characterized in that: The air gap between the second lens (2) and the third lens (3) is between 0.1 mm and 0.5 mm, the air gap between the third lens (3) and the aperture stop (10) is between 0.1 mm and 0.5 mm, the air gap between the aperture stop (10) and the fourth lens (4) is between 0.4 mm and 1 mm, the air gap between the fourth lens (4) and the fifth lens (5) is between 0.4 mm and 1 mm, the air gap between the sixth lens (6) and the seventh lens (7) is between 0.1 mm and 0.5 mm, the air gap between the eighth lens (8) and the ninth lens (9) is between 0.1 mm and 0.5 mm, and the air gap between the ninth lens (9) and the imaging plane (11) is between 6 mm and 12 mm.

7. An electronic device, characterized in that: A multi-megapixel day and night confocal imaging lens as described in any one of claims 1-6.

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