CN207133507U

CN207133507U - A kind of pre-objective of endoscope

Info

Publication number: CN207133507U
Application number: CN201720890891.1U
Authority: CN
Inventors: 李凯; 朱晓冬; 李慧
Original assignee: Anhui Aerospace Biotechnology Co Ltd
Current assignee: Anhui Aerospace Biotechnology Co Ltd
Priority date: 2017-07-21
Filing date: 2017-07-21
Publication date: 2018-03-23
Anticipated expiration: 2027-07-21

Abstract

The utility model discloses a kind of pre-objective of endoscope, including front lens, aperture diaphragm, the first rear lenses and the second rear lenses in lens barrel are sequentially arranged in from object side, and front lens has negative power, and the first rear lenses and the second rear lenses have positive light coke；The radius of curvature of front lens surface is respectively 1.44mm and 0.455mm, and the radius of curvature on the first rear lenses surface is respectively 0.382mm and 0.35mm, and the radius of curvature on the second rear lenses surface is respectively 0.716mm and infinity；The thickness of front lens, the first rear lenses and the second rear lenses is respectively 0.142mm, 0.404mm and 0.285mm；The spacing of front lens and aperture diaphragm is 0.285mm, and the spacing of aperture diaphragm and the first rear lenses is that 0.1mm, the first rear lenses and the second rear lenses spacing are 0.362mm；With small size, big visual field, as matter it is good the advantages of, meet medical use demand.

Description

A kind of pre-objective of endoscope

Technical field

Technical field of medical instruments is the utility model is related to, specifically a kind of pre-objective of endoscope.

Background technology

With the development of science and technology, medical endoscope has been widely used in medical field, it be the mankind spy on, Treat one of important tool of people's intracorporeal organ.And the application of medical endoscope clinically is increasingly popularized, it to Miniaturization, be multi-functional, high as matter develops.

According to the use demand of actual medical endoscope, endoscope must is fulfilled for small size, big visual field, as the bar such as matter is good Part, so the pre-objective coupled system as the defeated endoscopic images system important component of fiber must also have small chi Very little, big visual field, as matter it is good the features such as.

Utility model content

The purpose of this utility model is to provide a kind of pre-objective of endoscope, and the pre-objective has small size, big Visual field, as matter it is good the advantages of, meet medical use demand.

Technical scheme is used by the utility model solves its technical problem：

A kind of pre-objective of endoscope, including be sequentially arranged in from object side in lens barrel front lens, aperture diaphragm, first Rear lenses and the second rear lenses, front lens have negative power, and the first rear lenses and the second rear lenses have positive light coke；

The radius of curvature of front lens surface is respectively 1.44mm and 0.455mm, and the radius of curvature on the first rear lenses surface is divided Not Wei -0.382mm and -0.35mm, the radius of curvature on the second rear lenses surface be respectively 0.716mm with it is infinitely great；

The thickness of front lens, the first rear lenses and the second rear lenses is respectively 0.142mm, 0.404mm and 0.285mm；

The spacing of front lens and aperture diaphragm is 0.285mm, and the spacing of aperture diaphragm and the first rear lenses is 0.1mm, the The spacing of one rear lenses and the second rear lenses is 0.362mm；

Front lens, the first rear lenses and the second rear lenses wavelength be refractive index at 588nm be respectively 1.528554, 1.729160 with 1.548300；Front lens, the first rear lenses are respectively for the Abbe number at 588nm in wavelength with the second rear lenses 76.975515,54.499235 and 74.244488.

The beneficial effects of the utility model are：While to meet big visual field, make peripheral field light in subsequent optical member Incidence angle on part is smaller, and front lens is using the larger negative eyeglass of curvature；Further to reduce the curvature of field, the negative lens materials of selection Refractive index it is smaller；To correct the astigmatism and chromatic longitudiinal aberration of whole system, microscope group before and after aperture diaphragm using form backwards, So that the aberration of front and rear microscope group hangs down, axle amount is cancelled out each other；The optical coupling system that this patent is made up of the mutual cooperation of each lens, tool Have small size, big visual field, as matter it is good the advantages of, meet medical use demand.

Brief description of the drawings

The utility model is further illustrated with reference to the accompanying drawings and examples：

Fig. 1 is structural representation of the present utility model；

Fig. 2 is principle schematic of the present utility model；

Fig. 3 is modulation transfer function curve map of the present utility model；

Fig. 4 is the curvature of field of the present utility model and distortion curve figure；

Fig. 5 is encircled energy curve map of the present utility model.

Embodiment

As shown in figure 1, the utility model provides a kind of pre-objective of endoscope, including lens barrel is sequentially arranged in from object side Front lens 2, aperture diaphragm 3, the first rear lenses 4 and the second rear lenses 5 in 1, front lens 2 have a negative power, after first thoroughly The rear lenses 5 of mirror 4 and second have positive light coke；

The radius of curvature of a front surface and a rear surface of front lens 2 is respectively 1.44mm and 0.455mm, the first rear lenses 4 The radius of curvature of a front surface and a rear surface is respectively -0.382mm and -0.35mm, a front surface and a rear surface of the second rear lenses 5 Radius of curvature is respectively 0.716mm and infinity, i.e., surface is plane thereafter；

The thickness a1 of front lens 2 is 0.142mm, and the thickness a4 of the first rear lenses 4 is 0.404mm, the thickness of the second rear lenses 5 Degree a6 is 0.285mm；The thickness of aperture diaphragm 3 can be neglected；

The spacing a2 of front lens 2 and aperture diaphragm 3 is 0.285mm, and the spacing a3 of aperture diaphragm 3 and the first rear lenses 4 is 0.1mm, the first rear lenses 4 and the second rear lenses 5 spacing a5 are 0.362mm；

Front lens 2, the first rear lenses 4 are respectively for the refractive index at 588nm in wavelength with the second rear lenses 5 1.528554,1.729160 and 1.548300；Front lens 2, the first rear lenses 4 and the second rear lenses 5 are at 588nm in wavelength Abbe number is respectively 76.975515,54.499235 and 74.244488.

The optical coupling system that the utility model pre-objective is formed has following parameter：Effective F numbers are 4, magnifying power for- 0.038th, angle of half field-of view is 45 °, picture altitude 0.27mm, rear focus BF are 0mm, total length a7 is 1.53mm, focal length f is 0.265mm。

With reference to shown in Fig. 2, the utility model analyzes design criteria in the case where meeting the requirement of endoscope small size, big visual field, Using the image space telecentric system system of " negative-just " type.

In coherent fiber bundle objective lens design, the total reflection condition for meeting optical fiber is first had to, makes the numerical aperture of incident ray small In the numerical aperture of optical fiber.Again because the imaging beam of object point is symmetrical on optical axis on axle, coherent fiber bundle can be fully entered；And axle Foreign object point incident beam is symmetrical on chief ray；The incidence angle of one part glazed thread or the lower light of a part, which will exceed, passes picture The numerical aperture angle of beam, causes some light to be blocked.

Propagated to ensure on axle that whole imaging beams of object point and extra-axial object point can enter in coherent fiber bundle, should be by object lens It is designed to image space telecentric system.It is contemplated that if the lateral dimension mistake of optical system will be caused using image space telecentric system Greatly, it is difficult to apply.

Accordingly, it is considered to system aperture diaphragm is placed in inside microscope group, in typical photographic field lens structure, anti-tele-objective Have the characteristics that visual field is wide, focal length is short, simple in construction, it is easy to accomplish telecentric beam path in image space, while can ensure that optical system has There are smaller volume and quality.Therefore positive and negative group of separation is chosen, group is born in preceding, the anti-long distance of group front focal plane after aperture diaphragm is located at Initial configuration of the type photographic field lens as the object lens.

Optic test is carried out to the utility model pre-objective, with reference to shown in Fig. 3, the object lens are at 77 lp/mm frequencies Transfer function values more than 0.65, and close to diffraction limit；With reference to shown in Fig. 4, the object lens curvature of field is little, and distorts at edge Reach maximum at visual field, about -20% or so, this is due to that the objective angular field is big, and structure is asymmetric；With reference to shown in Fig. 5, abscissa For image patch radius, ordinate is encircled energy, it is seen that 90% energy is concentrated in the circle that radius is 10 μm under three visual fields, More than 95% energy is concentrated in the circle that radius is 15 μm.

It is described above, only it is preferred embodiment of the present utility model, not the utility model is made any formal Limitation；Any those skilled in the art, it is all available in the case where not departing from technical solutions of the utility model ambit The methods and technical content of the disclosure above makes many possible changes and modifications to technical solutions of the utility model, or is revised as The equivalent embodiment of equivalent variations.Therefore, every content without departing from technical solutions of the utility model, according to of the present utility model Technical spirit still falls within this practicality to any simple modification, equivalent substitution, equivalence changes and modification made for any of the above embodiments In the range of the protection of new technique scheme.

Claims

A kind of 1. pre-objective of endoscope, it is characterised in that including be sequentially arranged in from object side in lens barrel front lens, aperture Diaphragm, the first rear lenses and the second rear lenses, front lens have negative power, and the first rear lenses and the second rear lenses have positive light Focal power；

The radius of curvature of front lens surface is respectively 1.44mm and 0.455mm, and the radius of curvature on the first rear lenses surface is respectively- 0.382mm and -0.35mm, the radius of curvature on the second rear lenses surface is respectively 0.716mm and infinity；

The thickness of front lens, the first rear lenses and the second rear lenses is respectively 0.142mm, 0.404mm and 0.285mm；

The spacing of front lens and aperture diaphragm is 0.285mm, and the spacing of aperture diaphragm and the first rear lenses is 0.1mm, after first The spacing of lens and the second rear lenses is 0.362mm；

Front lens, the first rear lenses and the second rear lenses wavelength be refractive index at 588nm be respectively 1.528554, 1.729160 with 1.548300；Front lens, the first rear lenses are respectively for the Abbe number at 588nm in wavelength with the second rear lenses 76.975515,54.499235 and 74.244488.