Endoscope telecentric optical imaging lens

Abstract

The utility model discloses a telecentric optical imaging lens of an endoscope in the technical field of optical imaging lenses. Comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens and a fifteenth lens in sequence from the object side to the image side along the same optical axis. The object side surface and the image side surface of each lens are aspheric surfaces.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging lenses, and particularly relates to an endoscope telecentric optical imaging lens. Background Art

[0002] An endoscope generally refers to a medical instrument that enters the human body through various ducts to observe the internal conditions of the human body. The endoscope requires a small lens volume while maintaining high-definition imaging.

[0003] However, the existing endoscopes still need to be optimized in terms of lens configuration and parameter requirements, and the imaging quality needs to be improved. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an endoscope telecentric optical imaging lens to solve the technical problem of low imaging quality of the endoscope in the prior art.

[0005] To solve the above technical problem, the utility model specifically provides an endoscope telecentric optical imaging lens, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens from the object side to the image side along the same optical axis;

[0006] The object side surface and the image side surface of each lens are aspherical surfaces;

[0007] The first lens has a negative refractive power, its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis;

[0008] The second lens has a negative refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis;

[0009] The third lens has a refractive power, its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis;

[0010] The fourth lens has a refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis;

[0011] The fifth lens has a positive refractive power, its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis;

[0012] The sixth lens has a negative refractive power, its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis;

[0013] The seventh lens has a positive refractive power, its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis;

[0014] The eighth lens has a positive refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis.

[0015] The ninth lens has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis.

[0016] The tenth lens has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0017] The eleventh lens has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0018] The twelfth lens has a positive refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis.

[0019] The thirteenth lens has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis.

[0020] The fourteenth lens has a negative refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis.

[0021] The fifteenth lens has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0022] The endoscopic telecentric optical imaging lens satisfies the following relationship:

[0023] 0 < EPD / D32 < 0.15, 4.0 < f3 / f < 4.8, 1 < TSB / TSF < 1.2;

[0024] EPD: The entrance pupil diameter of the optical imaging lens, D32: The effective diameter of the image-side surface of the third lens, TSB: The distance from the object-side surface of the first lens to the diaphragm on the optical axis, TSF: The distance from the diaphragm to the object-side surface of the fifteenth lens on the optical axis, f: The focal length of the high-definition optical imaging lens, f3: The focal length of the third lens.

[0025] As a preferred embodiment of the present invention, the endoscopic telecentric optical imaging lens satisfies the following relationship:

[0026] -1 < |(V1 - V2)| < 1;

[0027] V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens.

[0028] As a preferred embodiment of the present invention, the endoscopic telecentric optical imaging lens satisfies the following relationship:

[0029] 0.08 ≤ ∑CT / ∑ET ≤ 0.12;

[0030] ∑CT is the distance between the central optical axes of each lens, and ∑ET is the edge thickness of each lens.

[0031] As a preferred embodiment of the present invention, the endoscopic telecentric optical imaging lens satisfies the following relationship:

[0032] 0.07 < f / TTL < 0.12;

[0033] TTL is the total optical length of the endoscopic telecentric optical imaging lens.

[0034] As a preferred embodiment of the present invention, the endoscopic telecentric optical imaging lens satisfies the following relationship:

[0035] -1 < (n1 + n3) / n2 < 3;

[0036] n1 is the maximum refractive index of the first lens, and n2 is the maximum refractive index of the second lens.

[0037] As a preferred embodiment of the present invention, the endoscopic telecentric optical imaging lens satisfies the following relationship:

[0038] 1.1 < Bf / Ff < 2.0;

[0039] Bf is the focal length from the first lens to the seventh lens in the front group of the diaphragm, and Ff is the focal length from the eighth lens to the fifteenth lens in the rear group of the diaphragm.

[0040] The present invention has the following beneficial effects compared with the prior art:

[0041] The endoscopic telecentric optical imaging lens provided by the present invention not only has a small volume but also effectively strengthens the correction of chromatic aberration to improve the imaging quality by reasonably configuring the materials of fifteen lenses. It can well correct aberrations, has high pixels, high resolution and excellent imaging quality, and can meet the requirements of endoscopic applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, other implementation drawings can be obtained by extending according to the provided drawings without creative efforts.

[0043] Figure 1 It is a schematic diagram of the endoscopic telecentric optical imaging lens in Embodiment 1 of the present invention;

[0044] Figure 2It is the field curvature and distortion curve graph of the endoscopic telecentric optical imaging lens in the first embodiment of the present utility model;

[0045] Figure 3 It is the axial aberration curve graph of the endoscopic telecentric optical imaging lens in the first embodiment of the present utility model;

[0046] Figure 4 It is the schematic diagram of the endoscopic telecentric optical imaging lens in the second embodiment of the present utility model;

[0047] Figure 5 It is the field curvature and distortion curve graph of the endoscopic telecentric optical imaging lens in the second embodiment of the present utility model;

[0048] Figure 6 It is the axial aberration curve graph of the endoscopic telecentric optical imaging lens in the second embodiment of the present utility model;

[0049] Figure 7 It is the schematic diagram of the endoscopic telecentric optical imaging lens in the third embodiment of the present utility model;

[0050] Figure 8 It is the field curvature and distortion curve graph of the endoscopic telecentric optical imaging lens in the third embodiment of the present utility model;

[0051] Figure 9 It is the axial aberration curve graph of the endoscopic telecentric optical imaging lens in the third embodiment of the present utility model;

[0052] Figure 10 It is the schematic diagram of the endoscopic telecentric optical imaging lens in the fourth embodiment of the present utility model;

[0053] Figure 11 It is the field curvature and distortion curve graph of the endoscopic telecentric optical imaging lens in the fourth embodiment of the present utility model;

[0054] Figure 12 It is the axial aberration curve graph of the endoscopic telecentric optical imaging lens in the fourth embodiment of the present utility model.

[0055] The reference numerals in the figure are respectively represented as follows:

[0056] The first lens: 101, 201, 301, 401;

[0057] The second lens: 102, 202, 302, 402;

[0058] The third lens: 103, 203, 303, 403;

[0059] The fourth lens: 104, 204, 304, 404;

[0060] The fifth lens: 105, 205, 305, 405;

[0061] The sixth lens: 106, 206, 306, 406;

[0062] The seventh lens: 107, 207, 307, 407;

[0063] The diaphragm: 108, 208, 308, 408;

[0064] The eighth lens: 109, 209, 309, 409;

[0065] The ninth lens: 1010, 2010, 3010, 4010;

[0066] The tenth lens: 1011, 2011, 3011, 4011;

[0067] The eleventh lens: 1012, 2012, 3012, 4012;

[0068] The twelfth lens: 1013, 2013, 3013, 4013;

[0069] The thirteenth lens: 1014, 2014, 3014, 4014;

[0070] The fourteenth lens: 1015, 2015, 3015, 4015;

[0071] The fifteenth lens: 1016, 2016, 3016, 4016. Detailed implementation manners

[0072] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0073] The present invention specifically provides an endoscope telecentric optical imaging lens, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a diaphragm, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens along the same optical axis from the object side to the image side;

[0074] The object side surface and the image side surface of each lens are aspherical surfaces;

[0075] The first lens has a negative refractive power, its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis;

[0076] The second lens has a negative refractive power, its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0077] The third lens has a refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0078] The fourth lens has a refractive power, its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0079] The fifth lens has a positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0080] The sixth lens has a negative refractive power, its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis;

[0081] The seventh lens has a positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0082] The eighth lens has a positive refractive power, its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0083] The ninth lens has a negative refractive power, its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis;

[0084] The tenth lens has a positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0085] The eleventh lens has a positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0086] The twelfth lens has a positive refractive power, its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0087] The thirteenth lens has a negative refractive power, its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0088] The fourteenth lens has a negative refractive power, its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis;

[0089] The fifteenth lens has a positive refractive power, its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0090] The endoscopic telecentric optical imaging lens satisfies the following relationships:

[0091] 0 < EPD / D32 < 0.15, 4.0 < f3 / f < 4.8, 1 < TSB / TSF < 1.2;

[0092] EPD: Entrance Pupil Diameter of the optical imaging lens, D32: Effective diameter of the image side of the third lens, TSB: Distance from the object side of the first lens to the diaphragm on the optical axis, TSF: Distance from the diaphragm to the object side of the fifteenth lens on the optical axis, f: Focal length of the high-definition optical imaging lens, f3: Focal length of the third lens.

[0093] The endoscope telecentric optical imaging lens provided by the present utility model not only has a small volume but also effectively strengthens the correction of chromatic aberration to improve the imaging quality by reasonably configuring the materials of fifteen lenses. It can well correct aberrations, has high pixels, high resolution and excellent imaging quality, and can meet the requirements of endoscopic applications.

[0094] As a preferred embodiment of the present utility model, the endoscope telecentric optical imaging lens satisfies the following relational expressions:

[0095] -1 < |(V1 - V2)| < 1;

[0096] V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens.

[0097] As a preferred embodiment of the present utility model, the endoscope telecentric optical imaging lens satisfies the following relational expressions:

[0098] 0.08 ≤ ∑CT / ∑ET ≤ 0.12;

[0099] ∑CT is the distance between the central optical axes of each lens, and ∑ET is the edge thickness of each lens.

[0100] As a preferred embodiment of the present utility model, the endoscope telecentric optical imaging lens satisfies the following relational expressions:

[0101] 0.07 < f / TTL < 0.12;

[0102] TTL is the total optical length of the endoscope telecentric optical imaging lens.

[0103] As a preferred embodiment of the present utility model, the endoscope telecentric optical imaging lens satisfies the following relational expressions:

[0104] -1 < (n1 + n3) / n2 < 3;

[0105] n1 is the maximum refractive index of the first lens, and n2 is the maximum refractive index of the second lens.

[0106] As a preferred embodiment of the present utility model, the endoscope telecentric optical imaging lens satisfies the following relational expressions:

[0107] 1.1 < Bf / Ff < 2.0;

[0108] The focal length of the first lens to the seventh lens in front of the diaphragm is Bf, and the focal length of the eighth lens to the fifteenth lens behind the diaphragm is Ff.

[0109] Embodiment 1

[0110] Please refer to Figures 1 to 3 , Figure 1 which shows a schematic diagram of the endoscopic telecentric optical imaging lens according to Embodiment 1 of the present invention. Figure 2 which shows the field curvature and distortion curves of the endoscopic telecentric optical imaging lens according to Embodiment 1 of the present invention from left to right in sequence. Figure 3 is the axial aberration curve of the endoscopic telecentric optical imaging lens of Embodiment 1.

[0111] In Embodiment 1, the endoscopic telecentric optical imaging lens includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107, a diaphragm 108, an eighth lens 109, a ninth lens 1010, a tenth lens 1011, an eleventh lens 1012, a twelfth lens 1013, a thirteenth lens 1014, a fourteenth lens 1015, and a fifteenth lens 1016, which are sequentially arranged from the object side to the image side along the same optical axis.

[0112] Specifically, the surface types of each lens are as follows:

[0113] The first lens 101 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis.

[0114] The second lens 102 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis.

[0115] The third lens 103 has a refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0116] The fourth lens 104 has a refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis.

[0117] The fifth lens 105 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0118] The sixth lens 106 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis.

[0119] The seventh lens 107 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0120] The eighth lens 109 has a positive refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0121] The ninth lens 1010 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is concave near the optical axis;

[0122] The tenth lens 1011 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0123] The eleventh lens 1012 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis;

[0124] The twelfth lens 1013 has a positive refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0125] The thirteenth lens 1014 has a negative refractive power. Its object-side surface is concave near the optical axis, and its image-side surface is convex near the optical axis;

[0126] The fourteenth lens 1015 has a negative refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is concave near the optical axis;

[0127] The fifteenth lens 1016 has a positive refractive power. Its object-side surface is convex near the optical axis, and its image-side surface is convex near the optical axis.

[0128] This endoscope telecentric optical imaging lens further includes an infrared filter, which is placed between the thirteenth lens 1014 and the object to be photographed. The infrared filter filters out the infrared band light entering the lens to avoid the infrared light irradiating the photosensitive chip and generating noise. Specifically, the infrared filter can be made of glass material to avoid affecting the focal length.

[0129] Refer to Table 1-1 and Table 1-2 below for reference.

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136] Table 1-1 shows the detailed structural data of the first embodiment, where the units of the radius of curvature, thickness, and focal length are millimeters, f is the focal length of the optical imaging lens group, Fno is the f-number, and EPD is the entrance pupil diameter of the optical imaging lens.

[0137] Surfaces 0 to 37 sequentially represent the surfaces from the object side to the image side. Among them, surfaces 2-34 sequentially represent the object surface of the first lens 101, the image surface of the first lens 101, the object surface of the second lens 102, the image surface of the second lens 102, the object surface of the third lens 103, the image surface of the third lens 103, the object surface of the fourth lens 104, the image surface of the fourth lens 104, the object surface of the fifth lens 105, the image surface of the fifth lens 105, the object surface of the sixth lens 106, the image surface of the sixth lens 106, the object surface of the seventh lens 107, the image surface of the seventh lens 107, the object surface of the eighth lens 109, the image surface of the eighth lens 109, the object surface of the ninth lens 1010, the image surface of the ninth lens 1010, the object surface of the tenth lens 1011, the image surface of the tenth lens 1011, the object surface of the eleventh lens 1012, the image surface of the eleventh lens 1012, the object surface of the twelfth lens 1013, the image surface of the twelfth lens 1013, the object surface of the thirteenth lens 1014, the image surface of the thirteenth lens 1014, the object surface of the infrared filter, and the image surface of the infrared filter.

[0138] Table 1-2 shows the aspheric coefficient data in the first embodiment. Among them, k represents the conic coefficient in the aspheric curve equation, and A4, A6, A8, A10, A12, A14, and A16 represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order aspheric coefficients of each surface.

[0139] The Second Embodiment

[0140] Please refer to Figures 4 to 6 , Figure 4 which shows a schematic diagram of the endoscopic telecentric optical imaging lens according to the second embodiment of the present invention. Figure 5 which shows the field curvature and distortion curves of the endoscopic telecentric optical imaging lens according to the second embodiment of the present invention from left to right in sequence. Figure 6 is the axial aberration curve diagram of the endoscopic telecentric optical imaging lens according to the second embodiment.

[0141] The endoscopic telecentric optical imaging lens in the second embodiment includes a first lens 201, a second lens 202, a third lens 203, a fourth lens 204, a fifth lens 205, a sixth lens 206, a seventh lens 207, a diaphragm 208, an eighth lens 209, a ninth lens 2010, a tenth lens 2011, an eleventh lens 2012, a twelfth lens 2013, a thirteenth lens 2014, a fourteenth lens 2015, and a fifteenth lens 2016 sequentially arranged along the same optical axis from the object side to the image side.

[0142] The surface shape of each lens is the same as that in the first embodiment.

[0143] Refer to Table 2-1 and Table 2-2 below for reference.

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] Embodiment Three

[0150] Please refer to Figures 7 to 9 , Figure 7 which shows a schematic diagram of the endoscopic telecentric optical imaging lens according to the third embodiment of the present invention, Figure 8 which shows the field curvature and distortion curves of the endoscopic telecentric optical imaging lens according to the third embodiment of the present invention from left to right in sequence, Figure 9 and is the axial aberration curve of the endoscopic telecentric optical imaging lens according to the third embodiment.

[0151] The endoscopic telecentric optical imaging lens in Embodiment Three includes a first lens 301, a second lens 302, a third lens 303, a fourth lens 304, a fifth lens 305, a sixth lens 306, a seventh lens 307, a diaphragm 308, an eighth lens 309, a ninth lens 3010, a tenth lens 3011, an eleventh lens 3012, a twelfth lens 3013, a thirteenth lens 3014, a fourteenth lens 3015, and a fifteenth lens 3016 that are sequentially arranged from the object side to the image side along the same optical axis;

[0152] The surface shape of each lens is the same as that in the first embodiment.

[0153] Refer to Table 3-1 and Table 3-2 below for reference.

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160] Embodiment 4

[0161] Please refer to Figures 10 to 12 , Figure 10 which shows a schematic diagram of the endoscopic telecentric optical imaging lens according to Embodiment 4 of the present utility model, Figure 11 and which shows the field curvature and distortion curve graphs of the endoscopic telecentric optical imaging lens according to Embodiment 4 of the present utility model from left to right in sequence, Figure 12 and which is the axial aberration curve graph of the endoscopic telecentric optical imaging lens for Embodiment 4.

[0162] In Embodiment 4, the endoscopic telecentric optical imaging lens includes a first lens 401, a second lens 402, a third lens 403, a fourth lens 404, a fifth lens 405, a sixth lens 406, a seventh lens 407, a diaphragm 408, an eighth lens 409, a ninth lens 4010, a tenth lens 4011, an eleventh lens 4012, a twelfth lens 4013, a thirteenth lens 4014, a fourteenth lens 4015, and a fifteenth lens 4016 that are sequentially arranged from the object side to the image side along the same optical axis;

[0163] The surface types of the respective lenses are the same as those in Embodiment 1.

[0164] In conjunction with the following Tables 4-1 and 4-2.

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171] The following table shows the conditions that the endoscopic telecentric optical imaging lens needs to meet in Embodiments 1 to 4

[0172]

[0173]

[0174] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. An endoscope telecentric optical imaging lens, characterized in that: The invention comprises, in order from the object side to the image side along the same optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a stop, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens and a fifteenth lens; The object side and image side of each lens are aspherical; The first lens has negative refractive power, its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis; The second lens has negative refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis; The third lens has refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The fourth lens element has refractive power, and its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis; The fifth lens element has positive refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The sixth lens element has negative refractive power, and its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis; The seventh lens element has positive refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The eighth lens element has positive refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis; The ninth lens element has negative refractive power, and its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis; The tenth lens element has positive refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The eleventh lens has positive refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The twelfth lens has positive refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis; The thirteenth lens has negative refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis; The fourteenth lens has negative refractive power, its object side surface is convex near the optical axis, and its image side surface is concave near the optical axis; The fifteenth lens has positive refractive power, its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis; The endoscope telecentric optical imaging lens satisfies the following relationship: 0<EPD / D32<0.15,4.0 <f3 / f<4.8,1<TSB / TSF<1.2; EPD: entrance pupil diameter of the optical imaging lens, D32: effective diameter of the image side of the third lens, TSB: distance from the object side of the first lens to the aperture on the optical axis, TSF: distance from the aperture to the object side of the fifteenth lens on the optical axis, f: focal length of the high-definition optical imaging lens, f3: focal length of the third lens.

2. The telecentric optical imaging lens for endoscope according to claim 1, characterized in that: The endoscope telecentric optical imaging lens satisfies the following relationship: -1<|(V1-V2)|<1; V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens.

3. The telecentric optical imaging lens for endoscope according to claim 1, characterized in that: The endoscope telecentric optical imaging lens satisfies the following relationship: 0.08≤∑CT / ∑ET≤0.12; ∑CT is the distance between the central optical axes of each lens, and ∑ET is the edge thickness of each lens.

4. The telecentric optical imaging lens for endoscope according to claim 1, characterized in that: The endoscope telecentric optical imaging lens satisfies the following relationship: 0.07<f / TTL<0.12; TTL is the total optical length of the endoscope telecentric optical imaging lens.

5. The telecentric optical imaging lens for endoscope according to claim 1, characterized in that: The endoscope telecentric optical imaging lens satisfies the following relationship: -1<(n1+n3) / n2<3; n1 is the maximum refractive index of the first lens, and n2 is the maximum refractive index of the second lens.

6. The telecentric optical imaging lens for endoscope according to claim 1, characterized in that: The endoscope telecentric optical imaging lens satisfies the following relationship: 1.1<Bf / Ff<2.0; Bf is the focal length of the first lens to the seventh lens in the front group of the aperture, and Ff is the focal length of the eighth lens to the fifteenth lens in the rear group of the aperture.

Images