CN218165243U - Fluorescence imaging endoscope objective lens with circumferential visual angle - Google Patents

Abstract

The utility model discloses a fluorescence imaging endoscope objective with circumferential visual angle, relating to the technical field of medical apparatus. The optical system of the lens sheath is composed of two first protective lenses, a polarization beam splitter prism and a polarizer, and the optical system of the objective lens is composed of a second protective lens, a biconcave lens, a first meniscus lens, a diaphragm, a second meniscus lens, a positive cemented lens and a fifth meniscus lens. When medical personnel used, can look for required inspection position through horizontal visual angle earlier, then through rotatory polaroid, filter horizontal visual angle light and make perpendicular visual angle light see through, simultaneously, rotatory endoscope sheath drives the prism rotatory to the view of the sick position within range all around, help medical personnel's understanding state of an illness more comprehensively, avoid misdiagnosis, miss diagnosis.

Description

Fluorescence imaging endoscope objective lens with circumferential visual angle

Technical Field

The utility model relates to the technical field of medical equipment, especially, relate to a fluorescence imaging endoscope objective that possesses circumference visual angle.

Background

An endoscope is a photoelectric instrument capable of reflecting the internal conditions of a human body and generally comprises an endoscope lens, a television camera system and a cold light source. The lens contains a set of imaging objective lens, relay lens and optical fiber. The optical fiber is connected with the cold light source and used for illumination; the imaging objective lens transmits the image to the ocular lens or the image sensor for medical staff to directly observe or amplify the image through the display, so that the internal condition can be observed more clearly, treatment can be carried out without operation, and the pain of a patient is greatly relieved.

In the prior art, the puncture sheath is often required to assist the endoscope in examining the patient. During operation, a health care provider typically inserts a puncture sheath at a site to be examined in a patient, and then extends an endoscope from within the hollow cavity of the puncture sheath into the patient to treat the same.

Because the observable range in the human body is small, and the puncture sheath is usually a hard structure, the sight line range is not adjustable, the examination of a patient has certain limitation, and the conditions of misdiagnosis, missed diagnosis and the like are easy to occur.

Meanwhile, when the observation visual field is changed, the endoscopes with different visual angles need to be selected and reinserted into the human body, and unnecessary damage to the patient is easily caused.

SUMMERY OF THE UTILITY MODEL

Objects of the invention

In view of this, an object of the present invention is to provide a fluorescence imaging endoscope objective lens with a circumferential viewing angle, so as to observe a scene in the peripheral range of a diseased part without replacing an endoscope with a different viewing angle, thereby improving the observation range.

(II) technical scheme

In order to achieve the above technical object, the utility model provides a fluorescence imaging endoscope objective that possesses circumference visual angle: the lens sheath optical system comprises a second protective lens, a biconcave lens, a first meniscus lens, a diaphragm, a second meniscus lens, a positive group cemented lens and a fifth meniscus lens;

the two first protective lenses are distributed in 90 degrees, and one of the first protective lenses, the polarization splitting prism, the polarizer, the second protective lens, the biconcave lens, the first meniscus lens, the diaphragm, the second meniscus lens, the positive group cemented lens and the fifth meniscus lens are sequentially arranged from the object side to the image side;

the central points of the polarization beam splitter prism, the polarizer, the second protective lens, the biconcave lens, the first meniscus lens, the diaphragm, the second meniscus lens, the positive group cemented lens and the fifth meniscus lens are all positioned on the same straight line;

the positive focus lens comprises a third meniscus lens, a biconvex lens and a fourth meniscus lens, the third meniscus lens and the fourth meniscus lens are distributed on two sides of the biconvex lens, and the third meniscus lens and the fourth meniscus lens are respectively adjacent to the second meniscus lens and the fifth meniscus lens;

biconcave type lens is 0.57mm with first meniscus type lens center air interval, first meniscus type lens is 5.98mm with diaphragm center air interval, the diaphragm is 0.67mm with second meniscus type lens center air interval, second meniscus type lens is 0.27mm with third meniscus type lens center air interval, fourth meniscus type lens is 0.1mm with fifth meniscus type lens center air interval.

Preferably, the first protective glass and the second protective glass are made of sapphire materials, the curvature of object space and image space planes of the first protective glass and the second protective glass is infinite, the center thickness of the first protective glass and the second protective glass is mm, the polarization splitting prism is a cube, the side length of the polarization splitting prism is 10mm, and the polarization splitting prism is made of H-ZLAF90 glass.

Preferably, the biconcave lens is made of H-LAK61 glass, the curvature radius of an object side concave surface of the biconcave lens is 6.48mm, the curvature radius of an image side concave surface of the biconcave lens is 2.42mm, and the center interval of the biconcave lens is 2.3mm.

Preferably, the first meniscus lens is made of H-ZBAF5 glass, one surface of the first meniscus lens adjacent to the biconcave type lens is a concave surface, one surface of the first meniscus lens adjacent to the second meniscus lens is a concave surface, the radius of curvature of the concave surface on the first meniscus lens is 7mm, the radius of curvature of the convex surface on the first meniscus lens is 2.45mm, and the center interval of the first meniscus lens is 2mm.

Preferably, the second meniscus lens is made of H-QF3 glass, one surface of the second meniscus lens adjacent to the first meniscus lens is a concave surface, one surface of the second meniscus lens adjacent to the third meniscus lens is a convex surface, the radius of curvature of the concave surface on the second meniscus lens is 1.58mm, the radius of curvature of the convex surface on the second meniscus lens is 2.49mm, and the center interval of the second meniscus lens is 2.9mm.

Preferably, the third meniscus lens adopts H-LAK3 glass to make, the one side of the adjacent second meniscus lens of third meniscus lens is the convex surface, the one side of the adjacent biconvex type lens of third meniscus lens is the concave surface, convex surface radius of curvature on the third meniscus lens is 10.64mm, concave surface radius of curvature on the third meniscus lens is 2.6mm, the centre spacing of third meniscus lens is 0.6mm.

Preferably, the biconvex lens is made of H-ZPK7 glass, one surface of the biconvex lens adjacent to the third meniscus lens is an object side convex surface, one surface of the biconvex lens adjacent to the fourth meniscus lens is an image side convex surface, the curvature radius of the object side convex surface of the biconvex lens is 2.6mm, the curvature radius of the image side convex surface of the biconvex lens is 3mm, and the center interval of the biconvex lens is 1.8mm.

Preferably, the fourth meniscus lens adopts H-ZF50 glass to make, the one side of the adjacent biconvex type lens of fourth meniscus lens is the concave surface, the one side of the adjacent fifth meniscus lens of fourth meniscus lens is the convex surface, the concave surface radius of curvature of fourth meniscus lens is 3mm, the convex surface radius of curvature of fourth meniscus lens is 8.5mm, the centre-to-centre spacing of fourth meniscus lens is 0.6mm.

Preferably, the fifth meniscus lens is made of H-QF56 glass, one surface of the fifth meniscus lens adjacent to the fourth meniscus lens is an object side convex surface, one surface of the fifth meniscus lens departing from the fourth meniscus lens is a concave surface, the object side convex surface curvature radius of the fifth meniscus lens is 7.68mm, the concave surface curvature radius of the fifth meniscus lens is 20.36mm, and the center interval of the fifth meniscus lens is 4.2mm.

Preferably, an endoscope sheath is arranged on the outer side of the endoscope sheath optical system, the first protective glasses are respectively fixed in the endoscope sheath and on the surface of the endoscope sheath, the polarization splitting prism is fixed in the endoscope sheath, one end, far away from the first protective glasses, of the endoscope sheath is rotatably connected with a lens barrel, the second protective glasses, the biconcave lens, the first meniscus lens, the diaphragm, the second meniscus lens, the positive group of cemented lenses and the fifth meniscus lens are all fixed in the lens barrel, a guide groove is formed in the outer surface of the endoscope sheath, a connecting ring is slidably connected in the guide groove, the periphery of the polarizer is fixed on the connecting ring, and the connecting ring is rotatably connected with the endoscope sheath.

According to the technical scheme, the method has the following beneficial effects:

1: when medical personnel used, can look for required inspection position through horizontal visual angle earlier, then through rotatory polaroid, filter horizontal visual angle light and make perpendicular visual angle light see through, simultaneously, rotatory endoscope sheath drives the prism rotatory to the view of the sick position within range all around helps medical personnel's more comprehensive understanding state of an illness, avoids misdiagnosis, the missed diagnosis.

2: the horizontal visual angle and the vertical visual angle are integrated in the same optical system, and the endoscope with the visual angles of 30 degrees, 45 degrees and 70 degrees, which is usually used, does not need to be replaced when in use, so that the operation flow is reduced, and the pain of a patient can be relieved by reducing the plugging times.

3: the system has a design wavelength of 0.43-0.9 μm, covers visible light and fluorescence wave bands, and can quickly and accurately search diseased parts through fluorescence imaging.

4: the system distortion is less than 0.2%, the direct perspective image is not deformed, digital image processing is not needed, the application effect of the video imaging operation is ensured, and the operation is ensured to be carried out smoothly.

5: the system adopts an image space telecentric structure, which is beneficial to reducing the aperture of a subsequent image transfer system and obtaining smaller endoscope size, and simultaneously, the image space telecentric structure ensures that the deviation of the central illumination and the marginal illumination of the image surface is within 10 percent, thereby ensuring the uniform integral illumination of the image surface and clear imaging.

6: the system design adopts the power distribution empirical theory and the primary aberration complementary optimization principle, so that the primary aberration on the surface of each element of the optical system is distributed uniformly, the manufacturing tolerance sensitivity is reduced, and the cost is reduced for system preparation.

7: the system has reliable engineering realizability and high expected image quality, and MTF is close to diffraction limit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of an endoscope optical system of the present invention;

FIG. 2 isbase:Sub>A schematic cross-sectional view taken at A-A of the endoscope of FIG. 1 in accordance with the present invention

FIG. 3 is a schematic view of the horizontal ray incident endoscope optical system of the present invention;

FIG. 4 is a schematic view of the vertical direction light incident endoscope optical system of the present invention;

FIG. 5 is a stippling diagram of an endoscopic system of the present invention;

FIG. 6 is a distorted view of the endoscopic system of the present invention;

FIG. 7 is an MTF plot of an endoscopic system of the present invention.

Description of the drawings: 1. a first protective mirror; 2. a polarization splitting prism; 3. a polarizer; 4. a second protective glass; 5. a biconcave lens; 6. a first meniscus lens; 7. a second meniscus lens; 8. a third meniscus lens; 9. a biconvex lens; 10. a fourth meniscus lens; 11. A fifth meniscus lens; 12. an endoscopic sheath; 13. a guide groove; 14. a connecting ring; 15. a diaphragm; 16. a lens barrel.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, identical or similar reference numerals indicate identical or similar parts and features. The drawings are only schematic representations of the concepts and principles of embodiments of the disclosure, and do not necessarily show specific dimensions and proportions of the various embodiments of the disclosure. Certain features that are part of a particular figure may be exaggerated in order to illustrate relevant details or structures of embodiments of the present disclosure.

Referring to FIGS. 1-6:

example one

A fluorescence imaging endoscope objective lens with a circumferential visual angle comprises a sheath optical system and an objective optical system, and is characterized in that one end of the sheath optical system departing from the objective optical system is an object side, and one end of the objective optical system departing from the sheath optical system is an image side;

the sheath optical system is composed of two first protective lenses 1, a polarization beam splitter prism 2 and a polarizer 3, an endoscope sheath 12 is arranged on the outer side of the sheath optical system, the two first protective lenses 1 are distributed at 90 degrees, the two first protective lenses 1 are respectively fixed in the endoscope sheath 12 and on the surface of the endoscope sheath 12, the polarization beam splitter prism 2 is fixed in the endoscope sheath 12, the object side light can penetrate through the first protective lenses 1 at two angles to the polarization beam splitter prism 2, the incident light beam passes through the polarization beam splitter prism 2, the light beam P component completely penetrates through the light beam, the S component is reflected in the direction perpendicular to 90 degrees, two linearly polarized light beams with the polarization directions perpendicular to each other are formed, and the light incident direction is shown in fig. 3 and 4;

the rear of the polarization beam splitter prism 2 is provided with a polarizer 3, the polarizer 3 is used as an analyzer and only allows linearly polarized light to transmit, and when the polarization beam splitter prism is assembled, the polarizer 3 can be rotated until the incident light P component completely transmits, and then the polarizer 3 rotates by 90 degrees and then the incident light S component completely transmits.

It is worth mentioning that the polarizer 3 is only allowed to be fixed when the light P component and the light S component completely penetrate through, the rotation angle is 90 degrees, and the medical staff can independently rotate the polarizer 3 to select the visual angle parallel to the optical axis or the visual angle perpendicular to the optical axis for observation when checking;

meanwhile, the rotatable endoscope sheath 12 drives the polarization splitting prism 2 to receive the scenery in the panoramic range, and the polarizer 3 rotates synchronously with the polarization splitting prism to ensure the consistency of the permeable polarization directions.

Furthermore, in order to rotate the polarizer 3 conveniently, a guide groove 13 is formed in the outer surface of the endoscope sheath 12, a connecting ring 14 is connected in the guide groove 13 in a sliding manner, the periphery of the polarizer 3 is fixed on the connecting ring 14, and the connecting ring 14 is connected with the endoscope sheath 12 in a rotating manner, so that the polarizer 3 can be driven by rotating the connecting ring 14.

It should be noted that the friction between the connection ring 14 and the endoscope sheath 12 is increased by a rubber sheet or the like, and the connection stability between the connection ring 14 and the endoscope sheath 12 is maintained by increasing the friction.

The objective optical system is composed of a second protective lens 4, a biconcave lens 5 with negative focal power, a first meniscus lens 6 with positive focal power, a diaphragm 15, a second meniscus lens 7 with positive focal power, a third meniscus lens 8 with negative focal power, a biconvex lens 9 with positive focal power, a fourth meniscus lens 10 with negative focal power and a fifth meniscus lens 11 with positive focal power, wherein the third meniscus lens 8, the biconvex lens 9 and the fourth meniscus lens 10 form a cemented lens.

Further, the first protective mirror 1 and the second protective mirror 4 are both made of sapphire materials, the curvature of the object space plane and the image space plane of the first protective mirror 1 and the second protective mirror 4 is infinite, the center thickness is 1mm, the polarization splitting prism 2 is a cube, the side length of the polarization splitting prism 2 is 10mm, and the polarization splitting prism 2 is made of H-ZLAF90 glass.

Furthermore, the biconcave lens 5 is made of H-LAK61 glass, the curvature radius of the object-side concave surface is 6.48mm, the curvature radius of the image-side concave surface is 2.42mm, and the center interval is 2.3mm.

Further, the first meniscus lens 6 was made of H-ZBAF5 glass, and had a concave curvature radius of 7mm, a convex curvature radius of 2.45mm, and centers at intervals of 2mm.

Further, the second meniscus lens 7 is made of H-QF3 glass, and has a concave curvature radius of 1.58mm, a convex curvature radius of 2.49mm, and center intervals of 2.9mm.

Further, the third meniscus lens 8 is made of H-LAK3 glass, and has a convex curvature radius of 10.64mm, a concave curvature radius of 2.6mm, and a center interval of 0.6mm.

Furthermore, the biconvex lens 9 is made of H-ZPK7 glass, and has a convex curvature radius of 2.6mm on the object side, 3mm on the image side and a center interval of 1.8mm.

Furthermore, the fourth meniscus lens 10 is made of H-ZF50 glass, and has a concave curvature radius of 3mm, a convex curvature radius of 8.5mm, and a center interval of 0.6mm.

Further, the fifth meniscus lens 11 is made of H-QF56 glass, and has a convex curvature radius of 7.68mm in the object side, a concave curvature radius of 20.36mm, and a center-to-center interval of 4.2mm.

Further, the air space between the biconcave lens 5 and the center of the first meniscus lens 6 is 0.57mm, the air space between the center of the first meniscus lens 6 and the center of the diaphragm 15 is 5.98mm, the air space between the center of the diaphragm 15 and the center of the second meniscus lens 7 is 0.67mm, the air space between the center of the second meniscus lens 7 and the center of the third meniscus lens 8 is 0.27mm, and the air space between the center of the fourth meniscus lens 10 and the center of the fifth meniscus lens 11 is 0.1mm.

The structural parameters of the endoscope optical system are shown in the table 1:

table 1:

the rear part of the endoscope objective lens is connected with a steering lens group and transmitted to an eyepiece, and images are observed by eyes or collected by a camera system through an adapter. The image rotating mirrors are generally 3-5 groups, and the imaging magnification of each group is-1. Thus, the objective imaging performance determines the imaging performance of the entire endoscope optical system. Compared with the prior art, the optical system can realize that the entrance pupil diameter D =0.4mm, F =2mm, the aperture F # =5, the distortion is less than 0.03%, MTF0.3@175lp/mm, the wavelength is 0.43-0.9 μm, the visible light and fluorescence wave bands are covered, and the fluorescence imaging examination can be carried out through the combined optimization of 6 optical lenses.

Example two

On the basis of the first embodiment, an endoscope sheath (12) is fixedly sleeved outside a first protective lens (1), the first protective lens (1) and a polarization splitting prism (2) are fixed in the endoscope sheath (12), one end of the endoscope sheath (12) is rotatably connected with a lens barrel (16), and the second protective lens (4), a biconcave lens (5), a first meniscus lens (6), a diaphragm (15), a second meniscus lens (7), a positive group cemented lens and a fifth meniscus lens (11) are all fixed in the lens barrel (16), so that when the endoscope sheath (12) is rotated, only the first protective lens (1), the polarization splitting prism (2) and a polarizer (3) can be driven to rotate, and the second protective lens (4), the biconcave lens (5), the first meniscus lens (6), the diaphragm (15), the second meniscus lens (7), the positive group cemented lens and the fifth meniscus lens (11) in the lens barrel (16) can be kept unmovable;

in order to rotate the polarizer 3 conveniently, a guide groove 13 is formed on the outer surface of the endoscope sheath 12, a connecting ring 14 is slidably connected to the guide groove 13, the outer periphery of the polarizer 3 is fixed to the connecting ring 14, and the connecting ring 14 is rotatably connected to the endoscope sheath 12.

Exemplary embodiments of the proposed solution of the present disclosure have been described in detail above with reference to preferred embodiments, however, it will be understood by those skilled in the art that many variations and modifications may be made to the specific embodiments described above, and that many combinations of the various technical features, structures presented in the present disclosure may be made without departing from the concept of the present disclosure, without departing from the scope of the present disclosure, which is defined by the appended claims.

Claims (10)

1. The fluorescence imaging endoscope objective lens with the circumferential visual angle comprises a sheath optical system and an objective optical system, and is characterized in that one end of the sheath optical system, which is far away from the objective optical system, is an object side, one end of the objective optical system, which is far away from the sheath optical system, is an image side, the sheath optical system consists of two first protective lenses (1), a polarization beam splitter prism (2) and a polarizer (3), and the objective optical system consists of a second protective lens (4), a biconcave lens (5), a first meniscus lens (6), a diaphragm (15), a second meniscus lens (7), a positive cemented lens and a fifth meniscus lens (11);

the two first protective lenses (1) are distributed in 90 degrees, and one of the first protective lenses (1), the polarization beam splitter prism (2), the polarizer (3), the second protective lens (4), the biconcave lens (5), the first meniscus lens (6), the diaphragm (15), the second meniscus lens (7), the positive group cemented lens and the fifth meniscus lens (11) are sequentially arranged from the object side to the image side;

the central points of the polarization beam splitter prism (2), the polarizer (3), the second protective lens (4), the biconcave lens (5), the first meniscus lens (6), the diaphragm (15), the second meniscus lens (7), the positive group cemented lens and the fifth meniscus lens (11) are all positioned on the same straight line;

the positive focus lens comprises a third meniscus lens (8), a biconvex lens (9) and a fourth meniscus lens (10), the third meniscus lens (8) and the fourth meniscus lens (10) are distributed on two sides of the biconvex lens (9), and the third meniscus lens (8) and the fourth meniscus lens (10) are respectively adjacent to the second meniscus lens (7) and the fifth meniscus lens (11);

biconcave type lens (5) are 0.57mm with first meniscus type lens (6) central air interval, first meniscus type lens (6) are 5.98mm with diaphragm (15) central air interval, diaphragm (15) are 0.67mm with second meniscus type lens (7) central air interval, second meniscus type lens (7) are 0.27mm with third meniscus type lens (8) central air interval, fourth meniscus type lens (10) are 0.1mm with fifth meniscus type lens (11) central air interval.

2. The objective lens of the fluorescence imaging endoscope with the circumferential visual angle according to claim 1, wherein the first protective lens (1) and the second protective lens (4) are made of sapphire materials, the curvature of the object space and the image space of the first protective lens (1) and the second protective lens (4) is infinite, the center thickness is 1mm, the polarization splitting prism (2) is a cube, the side length of the polarization splitting prism (2) is 10mm, and the polarization splitting prism (2) is made of H-ZLAF90 glass.

3. The objective lens of the fluorescence imaging endoscope with the circumferential visual angle according to claim 1, characterized in that the biconcave lens (5) is made of H-LAK61 glass, the curvature radius of the object-side concave surface of the biconcave lens (5) is 6.48mm, the curvature radius of the image-side concave surface of the biconcave lens (5) is 2.42mm, and the center spacing of the biconcave lens (5) is 2.3mm.

4. The objective lens of claim 1, wherein the first meniscus lens (6) is made of H-ZBAF5 glass, one surface of the first meniscus lens (6) adjacent to the biconcave lens (5) is a concave surface, one surface of the first meniscus lens (6) adjacent to the second meniscus lens (7) is a concave surface, the radius of curvature of the concave surface on the first meniscus lens (6) is 7mm, the radius of curvature of the convex surface on the first meniscus lens (6) is 2.45mm, and the centers of the first meniscus lenses (6) are spaced apart by 2mm.

5. The objective lens of the fluorescence imaging endoscope with the circumferential visual angle according to claim 1, wherein the second meniscus lens (7) is made of H-QF3 glass, one surface of the second meniscus lens (7) adjacent to the first meniscus lens (6) is a concave surface, one surface of the second meniscus lens (7) adjacent to the third meniscus lens (8) is a convex surface, the radius of curvature of the concave surface on the second meniscus lens (7) is 1.58mm, the radius of curvature of the convex surface on the second meniscus lens (7) is 2.49mm, and the center interval of the second meniscus lens (7) is 2.9mm.

6. The objective lens of the fluorescence imaging endoscope with the circumferential visual angle according to claim 1, wherein the third meniscus lens (8) is made of H-LAK3 glass, one surface of the third meniscus lens (8) adjacent to the second meniscus lens (7) is a convex surface, one surface of the third meniscus lens (8) adjacent to the biconvex lens (9) is a concave surface, the radius of curvature of the convex surface on the third meniscus lens (8) is 10.64mm, the radius of curvature of the concave surface on the third meniscus lens (8) is 2.6mm, and the center interval of the third meniscus lens (8) is 0.6mm.

7. The objective lens of an endoscope for fluorescence imaging with a circumferential visual angle according to claim 1, wherein the biconvex lens (9) is made of H-ZPK7 glass, one surface of the biconvex lens (9) adjacent to the third meniscus lens (8) is a convex object side, one surface of the biconvex lens (9) adjacent to the fourth meniscus lens (10) is a convex image side, the radius of curvature of the convex object side of the biconvex lens (9) is 2.6mm, the radius of curvature of the convex image side of the biconvex lens (9) is 3mm, and the center interval of the biconvex lens (9) is 1.8mm.

8. The fluorescence imaging endoscope objective lens with the circumferential visual angle of claim 1, characterized in that the fourth meniscus lens (10) is made of H-ZF50 glass, one surface of the fourth meniscus lens (10) adjacent to the biconvex lens (9) is a concave surface, one surface of the fourth meniscus lens (10) adjacent to the fifth meniscus lens (11) is a convex surface, the concave curvature radius of the fourth meniscus lens (10) is 3mm, the convex curvature radius of the fourth meniscus lens (10) is 8.5mm, and the center-to-center spacing of the fourth meniscus lens (10) is 0.6mm.

9. The objective lens of the fluorescence imaging endoscope with the circumferential view angle of claim 1, wherein the fifth meniscus lens (11) is made of H-QF56 glass, one surface of the fifth meniscus lens (11) adjacent to the fourth meniscus lens (10) is a convex object side, one surface of the fifth meniscus lens (11) away from the fourth meniscus lens (10) is a concave surface, the radius of curvature of the convex object side of the fifth meniscus lens (11) is 7.68mm, the radius of curvature of the concave surface of the fifth meniscus lens (11) is 20.36mm, and the center of the fifth meniscus lens (11) is spaced by 4.2mm.

10. The objective lens with the circumferential visual angle for the fluorescence imaging endoscope as claimed in claim 1, wherein an endoscope sheath (12) is disposed outside an endoscope sheath optical system, the two first protective lenses (1) are respectively fixed in the endoscope sheath (12) and on the surface of the endoscope sheath (12), the polarization splitting prism (2) is fixed in the endoscope sheath (12), one end of the endoscope sheath (12) far away from the first protective lens (1) is rotatably connected with a lens barrel (16), the second protective lens (4), the biconcave lens (5), the first meniscus lens (6), the diaphragm (15), the second meniscus lens (7), the positive group cemented lens and the fifth meniscus lens (11) are all fixed in the lens barrel (16), a guide groove (13) is disposed on the outer surface of the endoscope sheath (12), a connection ring (14) is slidably connected in the guide groove (13), the periphery of the polarizer (3) is fixed on the connection ring (14), and the connection ring (14) is rotatably connected with the endoscope sheath (12).

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