Ultra-thin diameter objective lens and ultra-thin fiber endoscope system

Abstract

The present invention relates to the technical field of medical devices, and particularly relates to an endoscope system with an ultra-fine diameter objective lens and an ultra-fine optical fiber. The ultra-fine diameter objective lens includes: a first lens element located at the front end, the first lens element being a negative lens, and the front end being the end of the ultra-fine diameter objective lens that is far from the light guiding optical fiber; a positive lens group located at the rear end, the positive lens group including a second lens element and a third lens element arranged in sequence from front to back, and the second lens element being located between the first lens element and the third lens element; wherein, the distance between the first lens element and the second lens element is greater than the distance between the second lens element and the third lens element, the rear end being the end of the ultra-fine diameter objective lens that is close to the light guiding optical fiber; and a diaphragm configured between the first lens element and the positive lens group.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to an endoscope system with an ultra-fine diameter objective lens and an ultra-fine optical fiber. Background Art

[0002] Endoscopes can assist doctors in minimally invasive or even non-invasive observation of internal organs and other tissue regions of interest in the human body, thereby further examining, operating on, and providing health care for lesions. Since the concept of endoscopes was first proposed by Philip Bozzini in 1806, the optical imaging of endoscopes has developed rapidly, helping endoscope doctors to make accurate diagnoses and reduce the pain of patients. With the rapid development of modern engineering science and technology in biomedicine, as a key component of the medical device system, the types, functions, and products of endoscopes are increasing. As one of the new types of endoscopes, the ultra-fine diameter fiber endoscope will have extensive applications such as peeping, positioning, examination, and medical treatment in special departments or fields such as otolaryngology, ophthalmology, and neurosurgery. At the same time, it provides great help for a series of clinical scientific research such as studying new treatment methods for specific intractable diseases.

[0003] The objective lens of the current endoscope is an objective lens imaging system composed of a total of four independent lens elements in two groups, front and back. There are many structural components, the assembly is relatively complex, the total radial length of the system is too long, and the diameter of the lens group lenses is large, which cannot meet the requirements for the front-end volume of the endoscope for more flexible, more delicate, and more precise surgeries and examinations. Summary of the Invention

[0004] The present invention provides an optical objective lens for an ultra-fine endoscope system that is simple in structure, has a large field of view, and can effectively improve the light flux; increases the doctor's ability to obtain information on the target site under difficult precision operations, thereby improving the reliability of minimally invasive surgeries; solves the technical problems in the current technology that the objective lens system of the ultra-fine endoscope does not adapt to a large field of view, small aperture, and large depth of field. In addition, the objective lens group of the present invention includes three lens elements, effectively reducing the overall external dimensions, reducing the difficulty of processing and assembly, and improving the system stability.

[0005] In a first aspect, an ultra-fine diameter objective lens is provided. The ultra-fine diameter objective lens is disposed at the front end of the light guide fiber of the fiber endoscope. The ultra-fine diameter objective lens includes:

[0006] A first lens element located at the front end. The first lens element is a negative lens, and the front end is the end of the ultra-fine diameter objective lens that is far from the light guide fiber.

[0007] a positive lens group at the rear end, the positive lens group comprising a second lens element and a third lens element arranged in sequence in front and behind, and the second lens element is located between the first lens element and the third lens element; wherein the distance between the first lens element and the second lens element is greater than the distance between the second lens element and the third lens element, and the rear end is an end of the ultra-fine diameter objective lens close to the light-guiding optical fiber;

[0008] An aperture stop is arranged between the first lens element and the positive lens group.

[0009] In a possible design, the diameter of the first lens element is less than 0.8 mm, and the diameters of the second lens element and the third lens element are both less than 0.45 mm.

[0010] In a possible design, the first lens element is a plano-concave negative lens, the second lens element is a meniscus negative lens, and the third lens element is formed by bonding a biconvex positive lens and a meniscus negative lens, wherein in the third lens element, the biconvex lens is located on the side facing the second lens element.

[0011] In a possible design, the distance between the first lens element and the second lens element is 1.32-1.50 mm, and the distance between the second lens element and the third lens element is 0.52-0.70 mm.

[0012] In a possible design, the maximum full field angle of the ultra-fine objective lens is 80°.

[0013] In a possible design, the length from the front side of the first lens element to the back side of the second lens element is 3.2-3.5 mm.

[0014] In a possible design, the objective lens is housed in a stainless steel package, and the outer diameter of the stainless steel package is less than 1.0 mm.

[0015] In a second aspect, an ultra-fine endoscope system is provided, comprising the ultra-fine objective lens and a light-guiding optical fiber as described in the first aspect, wherein the ultra-fine objective lens is located at the front end of the light-guiding optical fiber.

[0016] In one possible design, the numerical aperture of the ultra-fine objective lens in image space matches the numerical aperture of a single optical fiber in the light-guiding optical fiber, and the root mean square diameter of the diffuse spot formed by the ultra-fine objective lens on the imaging plane is smaller than the imaging diameter of the single optical fiber.

[0017] In one possible design, the system further includes: an image sensor located at the rear end of the light-guiding optical fiber; an image processor communicatively connected to the image sensor; and a display communicatively connected to the image processor.

[0018] The objective lens of the ultra-fine optical system provided by the present invention has the following advantages: Under the premise of image transmission through optical fibers, an optical objective lens for an ultra-fine endoscope system with a simple structure, a large field of view, and effectively increased light flux is provided, enhancing the doctor's ability to obtain information about the target site during precise operations, thereby improving the reliability of minimally invasive surgeries; it solves the technical problems existing in the current technology that the objective lens system of ultra-fine endoscopes is not suitable for large fields of view, small apertures, and large depths of field. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the lens structure arrangement of an ultra-fine diameter objective lens provided by the present invention.

[0020] Figure 2 It is an optical path diagram of the objective lens imaging of an ultra-fine diameter fiber endoscope system provided by the present invention.

[0021] Figure 3 It is a schematic diagram of a fiber endoscope system including an ultra-fine diameter objective lens. Detailed Embodiments

[0022] The following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those not specified in the embodiments, they are carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0023] Before further describing the specific embodiments of the present application, it should be understood that the protection scope of the present application is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present application are for the purpose of describing specific embodiments and not for limiting the protection scope of the present application; in the specification and claims of the present application, unless otherwise clearly stated in the text, the singular forms "a", "an", and "the" include the plural forms.

[0024] When the embodiments give a numerical range, it should be understood that unless otherwise specified in the present application, any value between the two endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the art of this technology. In addition to the specific methods, equipment, and materials used in the embodiments, according to the knowledge of those skilled in the art of this technology and the description of the present application, any methods, equipment, and materials similar to or equivalent to those described in the embodiments of the present application can also be used to implement the present application.

[0025] Disclosed in the embodiments of the present invention is an ultra-thin diameter objective lens and an ultra-thin fiber endoscope system including the objective lens, which can be applied to departments or fields such as otolaryngology, ophthalmology, neurosurgery, etc.

[0026] Next, in combination with Figure 1 , Figure 2 and Figure 3 the ultra-thin diameter objective lens and the ultra-thin fiber endoscope system provided by the embodiments of the present invention are described.

[0027] The embodiments of the present invention provide an optical objective lens system for an ultra-thin endoscope system. This fiber objective lens system can also be called an ultra-thin diameter objective lens, or simply referred to as an objective lens.

[0028] Figure 1 The lens structure of the ultra-thin diameter objective lens is shown. The objective lens includes two sets of front and rear lens groups, where the front lens group L1 is a negative lens group and the rear lens group L2 is a positive lens group; among them, the front negative lens group L1 includes a first lens element 1, and the rear positive lens group L2 includes a second lens element 2 and a third lens element 6; the first lens element 1 is placed at the very front of the ultra-thin diameter objective lens group, the second lens element 2 is arranged behind the first lens element 1, and the third lens element 6 is arranged behind the second lens element 2.

[0029] Among them, in this specification, "front" refers to the end far from the light guide fiber after the objective lens is set on the light guide fiber, and "rear" refers to the end close to the light guide fiber.

[0030] Among them, the distance between the front lens group L1 and the rear lens group L2 is greater than the maximum distance between the lenses within the lens group.

[0031] In this ultra-thin optical objective lens system, the diameter of the negative lens group L1 is less than 0.8 mm, and the diameter of the lens in the positive lens group L2 is less than 0.45 mm. With a small lens diameter, the objective lens selects a reverse telephoto structure and adopts a form of separating the negative and positive lens groups. When parallel light beams are incident, after being diverged by the aforementioned front group, they are imaged on the focal plane by the rear group. In this way, the principal plane of the objective lens moves backward out of the objective lens, and a working distance longer than the focal length can be obtained.

[0032] The first lens element 1 of the front lens group L1 is a plano-concave negative lens; in the rear lens L2, the second lens element 2 is a meniscus negative lens; and the third lens element 6 includes two lenses, a biconvex positive lens 3 and a meniscus negative lens 4, and the biconvex positive lens 3 is in the front and the meniscus negative lens 4 is in the rear, and the biconvex positive lens 3 and the meniscus negative lens 4 are bonded together with glue.

[0033] The distance between the first lens element plano-concave lens 1 of the front lens group L1 and the second lens element meniscus negative lens 2 of the rear lens group L2 is 1.32-1.50 mm; the distance between the second lens element meniscus negative lens 2 of the rear lens group L2 and the third lens element double cemented lens 6 is 0.52-0.70 mm. The optical objective system aperture 5 is placed between the front negative lens L1 and the rear positive lens L2.

[0034] Wherein, the maximum full field angle of the optical objective lens system can reach 75°-80°.

[0035] The total radial length of the optical objective lens system, that is, the length between the front surface of the first lens element 1 and the rear surface of the third lens element 6, is 3.2-3.5 mm. The objective lens group is packaged in medical stainless steel, and the outer diameter after packaging is less than 1.0 mm.

[0036] In the actual imaging process, the numerical aperture of the objective lens in the image space matches the numerical aperture of a single optical fiber of the imaging optical fiber bundle; the objective lens imaging system Figure 2 The root mean square diameter of the diffuse spot formed on the imaging plane 7 is smaller than the imaging diameter of a single imaging optical fiber, thereby avoiding crosstalk between pixels.

[0037] The objective lens is packaged for imaging, such as Figure 3 As shown, the imaging light signal is transmitted to the image sensor via the optical fiber, and then passes through the image processor to display the image on the display screen in real time. Finally, doctors and other users can perform relevant medical operations.

[0038] In summary, the present invention provides an optical objective lens of an ultra-fine endoscope system with a large field of view, which can increase the ability of doctors to obtain information about specific target parts during minimally invasive surgery, thereby improving the reliability of surgery; and solves the technical problem that the objective lens system of ultra-fine endoscopes in the current technology is not suitable for a large field of view, a small aperture, and a large depth of field. In addition, the objective lens group of the present invention has and only has three lens elements.

[0039] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An ultra-fine diameter objective lens, characterized in that, The ultra-thin diameter objective lens is disposed at the front end of the light guiding optical fiber of the fiber endoscope. The ultra-thin diameter objective lens includes: A first lens element located at the front end. The first lens element is a negative lens, and the front end is the end of the ultra-thin diameter objective lens away from the light guiding optical fiber; A positive lens group located at the rear end. The positive lens group includes a second lens element and a third lens element arranged in sequence from front to back, and the second lens element is located between the first lens element and the third lens element. Wherein, the distance between the first lens element and the second lens element is greater than the distance between the second lens element and the third lens element, and the rear end is the end of the ultra-thin diameter objective lens close to the light guiding optical fiber; A diaphragm configured between the first lens element and the positive lens group; The diameter of the first lens element is less than 0.8 mm, and the diameters of the second lens element and the third lens element are both less than 0.45 mm; The first lens element is a plano-concave negative lens, the second lens element is a meniscus negative lens, and the third lens element is formed by bonding a biconvex positive lens and a meniscus negative lens. Wherein, in the third lens element, the biconvex positive lens is located on the side facing the second lens element; The distance between the first lens element and the second lens element is 1.32 - 1.50 mm, and the distance between the second lens element and the third lens element is 0.52 - 0.70 mm.

2. The ultra-fine diameter objective lens according to claim 1, characterized in that, The maximum full field of view angle of the ultra-thin diameter objective lens is 80°.

3. The ultra-fine diameter objective lens according to claim 1, wherein The length from the front side of the first lens element to the rear side of the second lens element is 3.2 - 3.5 mm.

4. The ultra-fine diameter objective lens according to claim 1, wherein The objective lens is accommodated in a stainless steel package, and the outer diameter of the stainless steel package is less than 1.0 mm.

5. An ultra-fine fiber endoscope system, characterized in that, It includes the ultra-thin diameter objective lens according to any one of claims 1 - 4 and a light guiding optical fiber. Wherein, the ultra-thin diameter objective lens is located at the front end of the light guiding optical fiber.

6. The system according to claim 5, wherein The numerical aperture of the ultra-thin diameter objective lens in the image space matches the numerical aperture of a single optical fiber in the light guiding optical fiber, and the root mean square diameter of the diffraction spot formed by the ultra-thin diameter objective lens on the imaging plane is less than the imaging diameter of a single optical fiber.

7. The system according to claim 5 or 6, characterized in that, The system further includes an image sensor located at the rear end of the light guiding optical fiber; an image processor communicatively connected to the image sensor; and a display communicatively connected to the image processor.

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