Search

CN-116184650-B - Medical magnification amplification type endoscope optical system

CN116184650BCN 116184650 BCN116184650 BCN 116184650BCN-116184650-B

Abstract

The invention discloses a magnification-increasing endoscope optical system for medical treatment, which comprises a first lens group, a second lens group, a third lens group, a fourth lens group, an optical filter and a CMOS chip which are sequentially arranged from an object plane side, wherein the object plane and the CMOS chip are in object image conjugation relation, the first lens group is a negative refractive index lens group, the second lens group, the third lens group and the fourth lens group are positive refractive index lens groups, a system diaphragm is arranged between the first lens group and the second lens group, the third lens group is used for zooming and switching a low-power state and a high-power state along the movement of an optical axis of the endoscope system, and a first concave lens is arranged on the first lens group towards the object plane side. Compared with the prior art, the invention simplifies the zooming mode, has excellent and stable image quality in the zooming process, and has higher magnification and F number and higher resolution when in high magnification.

Inventors

  • YANG XIBIN

Assignees

  • 苏州光纫科技有限公司

Dates

Publication Date
20260512
Application Date
20220621

Claims (8)

  1. 1. The utility model provides a medical magnification amplification type endoscope optical system, its characterized in that includes from the first mirror group (1), second mirror group (2), third mirror group (3), fourth mirror group (4), light filter (5) and CMOS chip (6) that object plane (7) side arranged in proper order, object plane (7) with CMOS chip (6) each other are object image conjugation relation, first mirror group (1) is negative refractive index mirror group, second mirror group (2), third mirror group (3) and fourth mirror group (4) are positive refractive index mirror group, be provided with system diaphragm (8) between first mirror group (1) and second mirror group (2), third mirror group (3) are used for carrying out zoom and switch low-power state, high-power state along endoscope system's optical axis movement, first mirror group (1) orientation object plane (7) side is provided with first concave lens (11), first concave lens (11) focal length and the following system of focal length low-power ratio of endoscope system satisfy: In which, in the process, For the focal length of the first concave lens (11), The focal length of the endoscope is low.
  2. 2. A magnification-magnifying type endoscope optical system for medical use according to claim 1, wherein a focal length ratio of the first lens group (1) to the focal length ratio of the first concave lens (11) satisfies the following relationship: In which, in the process, Is the focal length of the first lens group (1).
  3. 3. The magnification-type endoscope optical system for medical use according to claim 1, wherein the focal length of the second lens group (2) and the focal length ratio of the endoscope low power system satisfy the following relationship of 3.1 3.5, Wherein, Is the focal length of the second lens group (2).
  4. 4. The medical magnification-type endoscope optical system according to claim 1, wherein the combined focal length of the third lens group (3) and the fourth lens group (4) satisfies the following relationship with the focal length ratio of the endoscope low power system in the endoscope low power state: In which, in the process, Is the combined focal length of the third lens group (3) and the fourth lens group (4).
  5. 5. A medical magnification-magnifying endoscope optical system according to claim 1, characterized in that the ratio of the center distances of the system diaphragm (8) to the first lens group (1) and the second lens group (2) satisfies the following relationship: In which, in the process, For the distance of the system diaphragm (8) to the second lens group (2), Is the distance from the first lens group (1) to the second lens group (2).
  6. 6. The magnification-type endoscope optical system for medical use according to claim 1, wherein a distance between the second lens group (2) and the fourth lens group (4) is constant during zooming of the endoscope system, and a moving direction of the third lens group (3) along an optical axis of the endoscope system coincides with a moving direction of the object plane (7).
  7. 7. The magnification-type endoscope optical system for medical use according to claim 2, wherein a ratio of a radius of curvature of the first concave lens (11) on the image plane side to a focal length of the first lens group (1) satisfies the following relationship In which, in the process, The curvature radius of the first concave lens (11) near the image plane side.
  8. 8. The medical magnification-type endoscope optical system according to claim 1, wherein the first concave lens (11) is made of quartz glass.

Description

Medical magnification amplification type endoscope optical system Technical Field The invention belongs to the field of endoscope optical systems, and particularly relates to a magnification-enlarging type endoscope optical system for medical treatment. Background Endoscopes are one of the medical devices that are currently clinically indispensable. With the miniaturization of cameras and the development of the diameter reduction of the insertion end of an endoscope, minimally invasive surgery has been developed. The conventional endoscope has a larger visual field, but has lower resolution, can only realize the purposes of doctor observation and operation, and cannot be used for pathological diagnosis. In order to solve the requirements of medical observation, operation and real-time precise diagnosis, the requirements of an endoscope optical system capable of zooming become stronger, and a large view field can be watched when the zoom endoscope is in low power, so that the operation is facilitated, the view field is small when the zoom endoscope is in high power, but the resolution is high, and the precise diagnosis is facilitated. The magnifying endoscope optical system can switch between a normal low power state and a magnified observation state by moving the lens group along the optical axis, and also changes the focal length. As disclosed in chinese patent CN201480016424.5, an magnifying endoscope optical system is disclosed, which comprises a plurality of lens groups and a negative lens connected to an imaging element, and is capable of switching between at least a normal observation state and a close-up magnification state by moving a part of the lens groups. In the prior art (such as the patent mentioned above), the movement adjustment of the lens group during zooming is complicated, the switching between the low power state and the high power state is inconvenient, and the magnification is not high. Disclosure of Invention The invention aims to provide a medical magnification-enlarging endoscope optical system, which simplifies a zooming mode, has excellent and stable image quality in zooming, and has higher magnification and F number and higher resolution when being high. In order to achieve the purpose, the medical magnification amplifying endoscope optical system comprises a first lens group, a second lens group, a third lens group, a fourth lens group, an optical filter and a CMOS chip which are sequentially arranged from an object plane side, wherein the object plane and the CMOS chip are in object image conjugation relation, the first lens group is a negative refractive index lens group, the second lens group, the third lens group and the fourth lens group are positive refractive index lens groups, a system diaphragm is arranged between the first lens group and the second lens group, the third lens group is used for moving along an optical axis of the endoscope system to zoom and switch a low-power state and a high-power state, a first concave lens is arranged on one side of the first lens group towards the object plane, and the ratio of the focal length of the first concave lens to the focal length of the endoscope low-power system satisfies the following relation: In which, in the process, For the focal length of the first concave lens (11),The focal length of the endoscope is low. The first lens group is composed of a plurality of lenses and is mainly used for collecting information of each view field of an object, and the whole lens group has a negative refractive index. The system diaphragm is positioned between the first lens group and the second lens group, the third lens group and the fourth lens group all have positive refractive indexes, divergent light rays of the first lens group are precisely converged and imaged, and the optical filter (formed by coating films on the surface of the protective sheet) is positioned in front of the CMOS chip. As a further description of the above technical solution: The focal length of the first lens group and the focal length ratio of the first concave lens satisfy the following relation: In which, in the process, Is the focal length of the first lens group. As a further description of the above technical solution: The focal length of the second lens group and the focal length ratio of the endoscope low power system satisfy the following relation of 3.1 3.5, Wherein,Is the focal length of the second lens group. As a further description of the above technical solution: The combined focal length of the third lens group and the fourth lens group is in a low-power state of the endoscope, and the focal length ratio of the combined focal length of the third lens group and the fourth lens group to the low-power system of the endoscope meets the following relation: In which, in the process, Is the combined focal length of the third lens group and the fourth lens group. As a further description of the above technical solution: the ratio of the center di