All-glass endoscope

Abstract

An all-glass endoscope is characterized by sequentially comprising a first lens (L1) which is a negative lens, a second lens (L2) which is a positive lens, a third lens (L3) which is a positive lens, a fourth lens (L4) which is a positive lens, a fifth lens (L5) which is a negative lens, a sixth lens (L6) which is a positive lens, a seventh lens (L7) which is a negative lens and an optical filter (IR). Wherein the first lens (L1) and the second lens (L2) form a first lens group (E1), the fourth lens (L4) and the fifth lens (L5) form a second lens group (E2), the sixth lens (L6) and the seventh lens (L7) form a third lens group (E3), and an optical filter (IR) is arranged; f1 / F is greater than or equal to-0.9 and less than or equal to 0; 1.59 < = F2 / F < = 3.5; -8 < = F3 / F < =-6; 0.5 < = f / F < = 2.5; the all-glass endoscope has the advantages of stable optical performance, small size, wide visual field, high imaging quality and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical imaging technology, and more particularly relates to a full glass endoscope. BACKGROUND

[0002] In recent years, endoscope lens technology has developed rapidly in the direction of high resolution, miniaturization and multi-functional integration. Traditional endoscopes mostly use plastic or mixed material lenses, which are prone to thermal deformation and aging, which greatly affects the imaging quality. Full glass endoscopes have gradually become a research hotspot in high-end medical and industrial detection fields due to their stable optical performance and strong corrosion resistance. To make up for the shortcomings of traditional endoscopes, a full glass endoscope is further described herein. SUMMARY

[0003] In view of the problems existing in the prior art, the present application provides a full glass endoscope, which aims to make up for the shortcomings of traditional endoscopes such as thermal deformation, low imaging quality, and to realize stable optical performance, large field of view, clear imaging and other characteristics.

[0004] The present application is realized by the following technical solutions:

[0005] A full glass endoscope, characterized in that it comprises a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7) and an optical filter (IR), a total of 8 lenses; wherein the first lens (L1) and the second lens (L2) form a first lens group (E1), the fourth lens (L4) and the fifth lens (L5) form a second lens group (E2), and the sixth lens (L6) and the seventh lens (L7) form a third lens group (E3);

[0006] The first lens (L1) is made of glass and has a negative focal power, with a convex object side and a concave image side;

[0007] The second lens (L2) is made of glass and has a positive focal power, with a convex object side and a concave image side;

[0008] The third lens (L3) is made of glass and has a positive focal power, with a convex object side and a convex image side;

[0009] The fourth lens (L4) is made of glass and has a positive focal power, with a convex object side and a convex image side;

[0010] The fifth lens (L5) is made of glass and has a negative focal power, with a concave object side and a convex image side;

[0011] The sixth lens (L6) is made of glass, has positive refractive power, the object side surface is convex, and the image side surface is convex.

[0012] The seventh lens (L7) is made of glass, has negative refractive power, the object side surface is concave, and the image side surface is convex.

[0013] The all-glass endoscope satisfies the following conditional expressions:

[0014] -0.9≤F1 / F≤0;

[0015] 1.59≤F2 / F≤3.5;

[0016] -8≤F3 / F≤-6;

[0017] 0.5≤f / F≤2.5;

[0018] wherein F1, F2, F3, f, F are the effective focal length of the first lens group (E1), the second lens group (E2), the third lens group (E3), the third lens (L3), and the entire all-glass endoscope lens, respectively.

[0019] Preferably, the following relationship is satisfied:

[0020] 0.2≤ΣT1 / TTL≤0.5;

[0021] 0.1≤ΣT2 / TTL≤0.35;

[0022] 0.15≤ΣT3 / TTL≤0.3;

[0023] wherein ΣT1 is the axial distance from the object side surface of the first lens (L1) to the image side surface of the second lens (L2), ΣT2 is the axial distance from the object side surface of the fourth lens (L4) to the image side surface of the fifth lens (L5), ΣT3 is the axial distance from the object side surface of the sixth lens (L6) to the image side surface of the seventh lens (L7), and TTL is the distance on the optical axis from the object side surface of the first lens of the all-glass endoscope to the imaging surface.

[0024] Preferably, the following relationship is satisfied:

[0025] 140°≤FOV≤145°;

[0026] 3.5≤FNO≤4.5;

[0027] wherein FOV is the maximum field of view of the entire all-glass endoscope lens, and FNO is the F number of the entire all-glass endoscope lens.

[0028] Preferably, the following relationship is satisfied:

[0029] 0.45<D1 / D2<0.6;

[0030] Wherein, D1 is the entrance pupil diameter of the entire all-glass endoscope lens, and D2 is the exit pupil diameter of the entire all-glass endoscope lens.

[0031] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following characteristics:

[0032] (1) The lenses of the all-glass endoscope lens of the present application are all made of glass material, which has good optical performance stability, high temperature resistance and other characteristics;

[0033] (2) The field of view of the all-glass endoscope lens of the present application is 140°≤FOV≤145°, which effectively increases the field of view of the lens and facilitates the user to observe more details;

[0034] (3) The all-glass endoscope lens of the present application has the characteristics of small volume, small distortion and high resolution, and has high flexibility.

DRAWINGS

[0035] Figure 1 is a structural schematic diagram of the all-glass endoscope lens.

[0036] Figure 2 is an MTF diagram of the all-glass endoscope lens.

[0037] Figure 3 is an aberration curve diagram of the all-glass endoscope lens.

[0038] Figure 4 is a distortion diagram of the all-glass endoscope lens.

DETAILED DESCRIPTION

[0039] The following is a specific embodiment of the present application.

[0040] 1. An all-glass endoscope, characterized by: sequentially comprising a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and an optical filter (IR), a total of 8 lenses; wherein the first lens (L1) and the second lens (L2) form a first lens group (E1), the fourth lens (L4) and the fifth lens (L5) form a second lens group (E2), and the sixth lens (L6) and the seventh lens (L7) form a third lens group (E3).

[0041] The first lens (L1) is made of glass material and has negative optical power, the object side surface is convex, and the image side surface is concave;

[0042] The second lens (L2) is made of glass material and has positive optical power, the object side surface is convex, and the image side surface is concave;

[0043] The third lens (L3) is made of glass, has positive refractive power, and has a convex object side surface and a convex image side surface;

[0044] The fourth lens (L4) is made of glass, has positive refractive power, and has a convex object side surface and a convex image side surface;

[0045] The fifth lens (L5) is made of glass, has negative refractive power, and has a concave object side surface and a convex image side surface;

[0046] The sixth lens (L6) is made of glass, has positive refractive power, and has a convex object side surface and a convex image side surface;

[0047] The seventh lens (L7) is made of glass, has negative refractive power, and has a concave object side surface and a convex image side surface;

[0048] The all-glass endoscope satisfies the following conditional expressions:

[0049] -0.9≤F1 / F≤0;

[0050] 1.59≤F2 / F≤3.5;

[0051] -8≤F3 / F≤-6;

[0052] 0.5≤f / F≤2.5;

[0053] wherein F1, F2, F3, f, and F are the effective focal lengths of the first lens group (E1), the second lens group (E2), the third lens group (E3), the third lens (L3), and the entire all-glass endoscope lens, respectively.

[0054] 2. The all-glass endoscope according to claim 1, characterized in that:

[0055] 0.2≤ΣT1 / TTL≤0.5;

[0056] 0.1≤ΣT2 / TTL≤0.35;

[0057] 0.15≤ΣT3 / TTL≤0.3;

[0058] wherein ΣT1 is the axial distance from the object side surface of the first lens (L1) to the image side surface of the second lens (L2), ΣT2 is the axial distance from the object side surface of the fourth lens (L4) to the image side surface of the fifth lens (L5), ΣT3 is the axial distance from the object side surface of the sixth lens (L6) to the image side surface of the seventh lens (L7), and TTL is the distance on the optical axis from the object side surface of the first lens of the all-glass endoscope to the imaging surface.

[0059] 3. The all-glass endoscope according to claim 1 or 2, characterized in that:

[0060] 140°≤FOV≤145°;

[0061] 3.5≤FNO≤4.5;

[0062] wherein FOV is the maximum field of view of the entire all-glass endoscope lens, and FNO is the F number of the entire all-glass endoscope lens.

[0063] 4. The all-glass endoscope lens, characterized in that:

[0064] 0.45<D1 / D2<0.6;

[0065] wherein D1 is the entrance pupil diameter of the entire all-glass endoscope lens, and D2 is the exit pupil diameter of the entire all-glass endoscope lens.

[0066] In the lens data table of this embodiment, the units of the curvature radius and the thickness are mm.

[0067] Figure 1 is a structural schematic diagram of the all-glass endoscope lens.

[0068] Figure 2 is an MTF diagram of the all-glass endoscope lens.

[0069] Figure 3 is an aberration curve diagram of the all-glass endoscope lens.

[0070] Figure 4 is a distortion diagram of the all-glass endoscope lens.

[0071] The following table is the parameter table of the embodiment

[0072] Table 1 is a structural parameter table of an entire all-glass endoscope lens

[0073]

[0074]

[0075] The above is only the description of the optimal implementation case of the present application, and is not a limitation on the present application. Any modification made within the design and principle of the present application should be included in the protection scope of the present application.

Claims

1. An all-glass endoscope, characterized in that: It consists of eight lenses in total: a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and an IR filter. Among them, the first lens (L1) and the second lens (L2) form the first lens group (E1), the fourth lens (L4) and the fifth lens (L5) form the second lens group (E2), and the sixth lens (L6) and the seventh lens (L7) form the third lens group (E3). The first lens (L1) is made of glass and has negative optical power. Its object side is convex and its image side is concave. The second lens (L2) is made of glass and has positive optical power. Its object side is convex and its image side is concave. The third lens (L3) is made of glass, has positive optical power, and its object side and image side are both convex. The fourth lens (L4) is made of glass, has positive optical power, and has a convex object side and an convex image side. The fifth lens (L5) is made of glass and has negative optical power. Its object side is concave and its image side is convex. The sixth lens (L6) is made of glass, has positive optical power, and has a convex object side and an convex image side. The seventh lens (L7) is made of glass and has negative optical power. Its object side is concave and its image side is convex. This all-glass endoscope satisfies the following condition: -0.9≤F1 / F≤0; 1.59≤F² / F≤3.5; -8≤F3 / F≤-6; 0.5 ≤ f / F ≤ 2.5; F1, F2, F3, f, and F represent the effective focal lengths of the first lens group (E1), the second lens group (E2), the third lens group (E3), the third lens (L3), and the entire all-glass endoscope lens, respectively.

2. The all-glass endoscope according to claim 1, characterized in that: 0.2≤ΣT1 / TTL≤0.5; 0.1≤ΣT2 / TTL≤0.35; 0.15≤ΣT3 / TTL≤0.3; Where ΣT1 is the axial distance from the object side of the first lens (L1) to the image side of the second lens (L2), ΣT2 is the axial distance from the object side of the fourth lens (L4) to the image side of the fifth lens (L5), ΣT3 is the axial distance from the object side of the sixth lens (L6) to the image side of the seventh lens (L7), and TTL is the distance on the optical axis from the object side of the first lens of the all-glass endoscope to the imaging surface.

3. The all-glass endoscope according to claim 1, characterized in that: 140°≤FOV≤145°; 3.5 ≤ FNO ≤ 4.5; Wherein, FOV is the maximum field of view of the entire all-glass endoscope lens, and FNO is the F-number of the entire all-glass endoscope lens.

4. The all-glass endoscope according to claim 1, characterized in that: 0.45 < D1 / D2 < 0.6; Where D1 is the entrance pupil diameter of the entire all-glass endoscope lens, and D2 is the exit pupil diameter of the entire all-glass endoscope lens.

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