Refraction and reflection panoramic endoscope lens

Abstract

The invention provides a catadioptric panoramic endoscope lens. The system sequentially comprises a reflector, an aperture diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens from an object space to an image space. The aperture diaphragm is located between the reflector and the first lens; the first lens and the second lens, the third lens and the fourth lens, and the sixth lens and the seventh lens are glued to form a doublet lens; the optical surface of the reflector is an aspheric surface, and the optical surfaces of the other lenses are spherical surfaces. The system has the characteristics of wide view field range, small size, good imaging quality, compact structure, convenience in processing and the like, and can be applied to the field of panoramic imaging of human intestinal tracts.

Description

(I) Technical field

[0001] The invention relates to a catadioptric panoramic endoscope lens, which can be used for panoramic endoscope imaging of human intestines and belongs to the technical field of panoramic imaging. (II) Background technology

[0002] In recent years, gastrointestinal diseases in my country have always been in a high incidence state, and digestive tract diseases have increasingly become difficult diseases that plague people's health. Due to the small field of view and limited imaging range of ordinary endoscopes, they can only image a limited surrounding area, which may cause the lesion to be missed. Panoramic endoscopic imaging technology can obtain a full view of the intestine through capsule endoscopy or laparoscope, providing doctors with a richer field of vision. Therefore, panoramic endoscopic imaging technology can effectively reduce the blind spots of internal organs, has important application value in minimally invasive surgery and preoperative examinations, and has been a research hotspot in recent years.

[0003] The catadioptric panoramic optical system mainly obtains panoramic images with a large field of view through a reflector unit, that is, panoramic images of up to 360° in the sagittal direction and a certain angle in the meridian direction. Compared with panoramic imaging systems such as fisheye lenses, concentric lens optical systems and panoramic annular optical systems, it has the advantages of simple structure, smaller size and lower cost. (III) Summary of the invention

[0004] The object of the present invention is to provide a catadioptric panoramic endoscope head, aiming to provide a panoramic endoscope head with a simple and compact structure, a wide field of view and low cost.

[0005] The object of the present invention is achieved in that:

[0006] A catadioptric panoramic endoscope lens is composed of a reflector, an aperture stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens in sequence from the object side to the image side.

[0007] Furthermore, the system aperture stop is located between the reflector and the first lens, and the first lens and the second lens, the third lens and the fourth lens, and the sixth lens and the seventh lens are double-cemented lenses.

[0008] Furthermore, the optical surface of the system reflector is aspherical, and the optical surfaces of the other lenses are spherical.

[0009] Further, the refractive index n1 of the first lens of the system ranges from 1.5 < n1 < 1.6, and the dispersion v1 ranges from 46 < v1 < 47; the refractive index n2 of the second lens ranges from 1.6 < n2 < 1.7, and the dispersion v2 ranges from 60 < v2 < 61; the refractive index n3 of the third lens ranges from 1.6 < n3 < 1.7, and the dispersion v3 ranges from 60 < v3 < 61; the refractive index n4 of the fourth lens ranges from 1.8 < n4 < 1.9, and the dispersion v4 ranges from 25 < v4 < 26; the refractive index n5 of the fifth lens ranges from 1.6 < n5 < 1.7, and the dispersion v5 ranges from 60 < v5 < 61; the refractive index n6 of the sixth lens ranges from 1.6 < n6 < 1.7, and the dispersion v6 ranges from 60 < v6 < 61; the refractive index n7 of the seventh lens ranges from 1.8 < n7 < 1.9, and the dispersion v7 ranges from 25 < v7 < 26; the refractive index n8 of the eighth lens ranges from 1.4 < n8 < 1.5, and the dispersion v8 ranges from 90 < v8 < 91.

[0010] Further, the working field of view angle of the optical system in the sagittal direction is 360°, the working field of view angle in the meridional direction is from 30° to 99°, the total focal length is -0.53 mm, the F number is 3.3, the total length is 25 mm, the detection wavelength range is 486 nm to 656 nm, the image plane height is 1 mm, and it can meet the imaging requirements on the OV9734 imaging chip matched with it. (IV) BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic structural diagram of an embodiment of the catadioptric panoramic endoscope lens of the present invention.

[0012] Figure 2 It is an optical path diagram of an embodiment of the catadioptric panoramic endoscope lens of the present invention.

[0013] Figure 3 It is an MTF (Optical Transfer Function) diagram of an embodiment of the catadioptric panoramic endoscope lens of the present invention.

[0014] Figure 4 It is a spot diagram of an embodiment of the catadioptric panoramic endoscope lens of the present invention.

[0015] Figure 5 It is a defocused MTF diagram of an embodiment of the catadioptric panoramic endoscope lens of the present invention. (V) DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be further described below in conjunction with specific embodiments.

[0017] The present invention is a catadioptric panoramic endoscope lens, which is composed of a reflector 1, an aperture stop 2, a first lens 3, a second lens 4, a third lens 5, a fourth lens 6, a fifth lens 7, a sixth lens 8, a seventh lens 9, an eighth lens 10, and a target surface 11 in sequence from the object side to the image side.

[0018] Further, the system aperture stop is located between the mirror and the first lens, and the first lens and the second lens, the third lens and the fourth lens, and the sixth lens and the seventh lens are doublet lenses.

[0019] Further, the optical surface of the system mirror is an aspherical surface, and the optical surfaces of the remaining lenses are spherical surfaces.

[0020] Further, the mirror has a first surface S1 convex toward the image side; the first lens has a third surface S3 concave toward the object side and a fourth surface S4 convex toward the image side; the second lens has a fourth surface S4 concave toward the object side and a fifth surface S5 convex toward the image side; the third lens has a sixth surface S6 convex toward the object side and a seventh surface S7 convex toward the image side; the fourth lens has a seventh surface S7 concave toward the object side and an eighth surface S8 convex toward the image side; the fifth lens has a ninth surface S9 convex toward the object side and a tenth surface S10 convex toward the image side; the sixth lens has an eleventh surface S11 convex toward the object side and a twelfth surface S12 convex toward the image side; the seventh lens has a twelfth surface S12 concave toward the object side and a thirteenth surface S13 concave toward the image side; the eighth lens has a fourteenth surface S14 concave toward the object side and a fifteenth surface S15 concave toward the image side.

[0021] Further, the refractive index n1 of the system first lens ranges from 1.5 < n1 < 1.6, and the dispersion v1 ranges from 46 < v1 < 47; the refractive index n2 of the second lens ranges from 1.6 < n2 < 1.7, and the dispersion v2 ranges from 60 < v2 < 61; the refractive index n3 of the third lens ranges from 1.6 < n3 < 1.7, and the dispersion v3 ranges from 60 < v3 < 61; the refractive index n4 of the fourth lens ranges from 1.8 < n4 < 1.9, and the dispersion v4 ranges from 25 < v4 < 26; the refractive index n5 of the fifth lens ranges from 1.6 < n5 < 1.7, and the dispersion v5 ranges from 60 < v5 < 61; the refractive index n6 of the sixth lens ranges from 1.6 < n6 < 1.7, and the dispersion v6 ranges from 60 < v6 < 61; the refractive index n7 of the seventh lens ranges from 1.8 < n7 < 1.9, and the dispersion v7 ranges from 25 < v7 < 26; the refractive index n8 of the eighth lens ranges from 1.4 < n8 < 1.5, and the dispersion v8 ranges from 90 < v8 < 91.

[0022] Further, the working field of view angle of the optical system in the sagittal direction is 360°, the working field of view angle in the meridional direction is from 30° to 99°, the total focal length is -0.53 mm, the F number is 3.3, the total length is 25 mm, and the detection wavelength range is from 486 nm to 656 nm.

[0023] Further, the image plane height of the optical system is 1 mm, and it can meet the imaging requirements on the OV9734 imaging chip matched with it.

[0024] In this embodiment, the parameters of each surface are shown in Table 1 and Table 2 below.

[0025] Table 1: Optical component surface parameters

[0026] Table 2: Aspheric coefficients of the first surface K A1 A2 A3 A4 Aspheric coefficient -1.293 -7.039E-05 4.531E-07 6.287E-10 2.934E-11

[0027] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A catadioptric panoramic endoscope lens. Its characteristics are: From the object side to the image side, it consists of a reflecting mirror, an aperture stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens in sequence.

2. The catadioptric panoramic endoscope head according to claim 1, characterized in that: The system aperture stop is located between the reflecting mirror and the first lens. The first lens and the second lens, the third lens and the fourth lens, and the sixth lens and the seventh lens are doublet lenses.

3. The catadioptric panoramic endoscope head according to claim 1, characterized in that: The optical surface of the system reflecting mirror is an aspherical surface, and the optical surfaces of the remaining lenses are spherical surfaces.

4. The catadioptric panoramic endoscope head according to claim 1, characterized in that: For the system, the refractive index n1 of the first lens ranges from 1.5 < n1 < 1.6, and the dispersion v1 ranges from 46 < v1 < 47; the refractive index n2 of the second lens ranges from 1.6 < n2 < 1.7, and the dispersion v2 ranges from 60 < v2 < 61; the refractive index n3 of the third lens ranges from 1.6 < n3 < 1.7, and the dispersion v3 ranges from 60 < v3 < 61; the refractive index n4 of the fourth lens ranges from 1.8 < n4 < 1.9, and the dispersion v4 ranges from 25 < v4 < 26; the refractive index n5 of the fifth lens ranges from 1.6 < n5 < 1.7, and the dispersion v5 ranges from 60 < v5 < 61; the refractive index n6 of the sixth lens ranges from 1.6 < n6 < 1.7, and the dispersion v6 ranges from 60 < v6 < 61; the refractive index n7 of the seventh lens ranges from 1.8 < n7 < 1.9, and the dispersion v7 ranges from 25 < v7 < 26; the refractive index n8 of the eighth lens ranges from 1.4 < n8 < 1.5, and the dispersion v8 ranges from 90 < v8 < 91.

Images