Large-aperture micro-luminous night vision lens

Abstract

The application discloses a large-image-surface micro-light night vision lens, which comprises, in sequence from the object side to the image side, a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with negative refractive power, a sixth lens with positive refractive power, a seventh lens with negative refractive power and an eighth lens with positive refractive power. The first lens, the second lens, the third lens, the fourth lens, a diaphragm, the fifth lens, the sixth lens, the seventh lens and the eighth lens are arranged in sequence from the object side to the image side, wherein the first lens and the fourth lens are glass lenses, the second lens and the third lens are cemented lenses, and the fifth lens to the eighth lens are plastic aspheric lenses. The application adopts the design of combining four glass lenses and four plastic lenses, is beneficial to correcting secondary spectrum and high-order aberration, and simultaneously adopts the multiple plastic lenses, which is beneficial to lens structure design and reduces the number of lens used by the lens.

Claims

1. A large-image-size low-light night vision lens, characterized in that: From the object side to the image side, it successively includes: A first lens with a positive focal power, wherein the object side surface of the first lens is convex and the image side surface of the first lens is concave; A second lens with a positive focal power; A third lens with a negative focal power; A fourth lens with a positive focal power, wherein the object side surface of the fourth lens is convex and the image side surface of the fourth lens is concave; A fifth lens with a negative focal power, wherein the object side surface of the fifth lens is convex and the image side surface of the fifth lens is concave; A sixth lens with a positive focal power, wherein the object side surface of the sixth lens is concave and the image side surface of the sixth lens is convex; A seventh lens with a negative focal power, wherein the object side surface of the seventh lens is concave and the image side surface of the seventh lens near the optical axis is concave; An eighth lens with a positive focal power, wherein the object side surface of the eighth lens near the optical axis is convex and the image side surface of the eighth lens is convex; The first lens, the second lens, the third lens, the fourth lens, the aperture stop, the fifth lens, the sixth lens, the seventh lens and the eighth lens are arranged in sequence from the object side to the image side, wherein the first lens and the fourth lens are glass lenses, the second lens and the third lens are cemented lenses, and the fifth lens to the eighth lens are plastic aspherical lenses.

2. The large-image-size low-light night vision lens according to claim 1, characterized in that: This large image surface low-light night vision lens satisfies: 45.9mm < f < 46mm, TTL ≤ 39.1mm; f is the overall focal length of this large image surface low-light night vision lens, and TTL is the distance from the first lens of the optical lens to the imaging surface on the optical axis.

3. The large-image-size low-light night vision lens according to claim 1, characterized in that: This large image surface low-light night vision lens satisfies: 55 < |f1| < 70, 30 < |f2| < 35, 19 < |f3| < 23, 33 < |f4| < 36, 110 < |f5| < 160, 160 < |f6| < 240, 3 < |f7| < 5.5, 4 < |f8| < 7, where f1, f2, f3, f4, f5, f6, f7 and f8 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens respectively.

4. The large-image-size low-light night vision lens according to claim 2, characterized in that: The absolute value of the ratio of the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens to the overall focal length satisfies: 1 < |(f1 / f)| < 2, 0.6 < |(f2 / f)| < 0.8, 0.4 < |(f3 / f)| < 0.5, 0.7 < |(f4 / f)| < 0.8, 2 < |(f5 / f)| < 3.5, 3.5 < |(f6 / f)| < 5.2, 0.117 < |(f7 / f)| < 0.15, 0.096 < |(f8 / f)| < 0.15, where f is the overall focal length of this large image surface low-light night vision lens, 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, and f8 is the focal length of the eighth lens.

5. The large-image-size low-light night vision lens according to claim 2, characterized in that: This large image surface low-light night vision lens satisfies: 0.849 < TTL / f < 0.

9.

6. The large-image-size low-light night vision lens according to claim 2, characterized in that: This large-format low-light night vision lens meets the following requirements: 0.586 <SD max / TTL<0.6; where SD max TTL is the aperture of the largest lens element in the lens; TTL is the distance on the optical axis from the first lens of the optical lens to the imaging plane.

7. The large-image-size low-light night vision lens according to claim 1, characterized in that: The large-image low-light night vision lens satisfies the following conditions: nd1≤1.5; vd1>90, nd2≤1.5; vd2>80; nd2≥1.6; vd2<45; 4≤1.6; vd4>68; where nd1, nd2, nd3, and nd4 are the refractive indices of the first, second, third, and fourth lenses, respectively; and vd1, vd2, vd3, and vd4 are the Abbe numbers of the first, second, third, and fourth lenses, respectively.

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