CN206470464U

CN206470464U - A kind of fully separating formula endoscope lens

Info

Publication number: CN206470464U
Application number: CN201720184557.4U
Authority: CN
Inventors: 陈曦; 严永强
Original assignee: Chengdu Poly Optical Technology Co Ltd
Current assignee: Chengdu Poly Optical Technology Co Ltd
Priority date: 2017-02-28
Filing date: 2017-02-28
Publication date: 2017-09-05
Anticipated expiration: 2027-02-28

Abstract

The utility model discloses a kind of fully separating formula endoscope lens, including the first lens being sequentially connected from object side, second lens, optical filter, aperture diaphragm, 3rd lens, 4th lens and image sensor element, first lens, second lens, optical filter, aperture diaphragm, 3rd lens, 4th lens and image sensor element are using air as the setting that is spaced apart, first lens are that thing flank radius is more than image side curvature radius, and concave surface thereon is towards the negative lens of image side surface, second lens are that thing flank radius is less than image side curvature radius, and the positive lens convex surface facing thing side thereon, 3rd lens are positive lens, 4th lens are that thing flank radius is less than image side curvature radius, and concave surface thereon is towards the negative lens of thing side.The utility model uses the composition structure of fully separating formula, and simple in construction, technique cost of manufacture is low, it is to avoid the problem of cemented component is easily caused failure under high/low temperature, with stronger practicality.

Description

A kind of fully separating formula endoscope lens

Technical field

The utility model belongs to the technical field of endoscope, and in particular to a kind of fully separating formula endoscope lens.

Background technology

At present, widely used fujinon electronic video endoscope uses and disinfection way is submerged under normal temperature, normal temperature submergence disinfection way There are still certain Infection probability, the rigid endoscope used in Minimally Invasive Surgery, due to needing higher level of sterilization, is adopted Sterilized, in order to reduce Infection probability, sterilized using the higher HTHP mode of level of sterilization with HTHP Operation would be even more beneficial to the clinical practice of fujinon electronic video endoscope.

Endoscope lens, largely employing optical cement is used for two panels different materials lens progress gluing unit into glued mirror The aberration of optical system is reduced, but there is failure risk, the light of the glued mirror of one side under high/low temperature circulation change in glued mirror Learn glue and colored state is easily changed to by water white transparency state when long-time is heated at high temperature, and then cause absorbance to increase, image Luminance-reduction and ultimate failure；On the other hand, in order to reduce aberration, glued mirror is that two kinds of different optical materials are carried out into gluing. In high/low temperature circulation change, object expands with heat and contract with cold constantly, because the thermal coefficient of expansion of different materials is different, for a long time The lower produced stress of high/low temperature circulation is easily caused glue-line aging to two panels cracking glasses and failed.

In addition, glued mirror means more complicated structure and technique, the complexity of structure and the difficulty of processing technology are not only Product cost is added, product reliability and life-span is also reduced.

The endoscope lens angle of visual field generally reaches 140 °, belongs to ultra-wide angle optical system, under conditions of ultra-wide angle imaging, by It is excessive in optical surface incident angle in light so that astigmatism and notable, the conventional endoscope lens of curvature of the image, in order to reduce The influence of astigmatism and curvature of the image, using the lens combination including glued mirror, but its is complicated, and technology difficulty is high.

Utility model content

The purpose of this utility model is in view of the shortcomings of the prior art there is provided a kind of fully separating formula endoscope lens, with Solve that existing endoscope lens are complicated, technology difficulty is high and avoid the problem of cemented component is easily caused failure under high/low temperature.

To reach above-mentioned purpose, the utility model is adopted the technical scheme that：

A kind of fully separating formula endoscope lens, including be sequentially connected from object side the first lens, the second lens, filter Piece, aperture diaphragm, the 3rd lens, the 4th lens and image sensor element；

First lens, the second lens, optical filter, aperture diaphragm, the 3rd lens, the 4th lens and image sensor element with Air is the setting that is spaced apart；

First lens are that thing flank radius is more than image side curvature radius, and concave surface bearing towards image side surface thereon Lens；

Second lens be thing flank radius be less than image side curvature radius, and thereon convex surface facing thing side just Lens；

3rd lens are positive lens；

4th lens are that thing flank radius is less than image side curvature radius, and concave surface bearing towards thing side thereon Lens；

Fully separating formula endoscope lens meet following conditions：

-1.0<f1/f<-0.9

1.1<f12/f34<2.1

-1.1<f4/f<-0.9

Wherein, f is object lens whole focal length, and f1 is the focal length of the first lens, and f12 is the combination of the first lens and the second lens Focal length, f34 is the 3rd lens and the 4th lens combination focal length, and f4 is the focal length of the 4th lens.

Preferably, the first lens and the second lens meet following conditions：

0.4<d2/(n2*d3)<0.6

-0.7<r2/r3<-0.4

Wherein, d2 is the thickness of airspace between the first lens and the second lens, and d3 is the second lens axial width, and n2 is Refractive index of second lens under d light, r2 is the first concave lens surface radius of curvature, and r3 is the second convex lens surface radius of curvature.

Preferably, a length of 587.5nm of d light waves.

Preferably, aperture diaphragm, the second lens and the 3rd lens meet following condition

1.1<Tf/Tb<1.4

Wherein, Tf is airequivalent thickness of the aperture diaphragm thing side to the second lens image side surface, and Tb is aperture diaphragm picture Airequivalent thickness of the side to the 3rd lens thing side.

Preferably, image sensor element is made up of the watch crystal and photosurface close to the 4th lens.

The fully separating formula endoscope lens that the utility model is provided, have the advantages that：

Set between this fully separating each lens of formula endoscope lens with airspace, without using optical cement to each optical element Carry out glued, it is to avoid the problem of endoscope lens fail under high/low temperature condition；The first lens meet the bar of ultra-wide angle simultaneously The astigmatism and the curvature of field of the first lens can be greatly lowered in part, and a large amount of astigmatisms and the curvature of field as caused by ultra-wide angle, the second lens, Incident angle of the light in the second lens surface is reduced, and then reduces aberration balancing difficulty；The setting of optical filter and the 3rd lens, Ensure the deviation symmetrical structure that optical filter will not be excessive, while filtering out the infrared light into optical system, lift picture contrast, Optimize picture quality.

The utility model uses the composition structure of fully separating formula, and simple in construction, technique cost of manufacture is low, it is to avoid high/low temperature The problem of lower cemented component is easily caused failure, with stronger practicality.

Brief description of the drawings

Fig. 1 is the structural representation of fully separating formula endoscope lens.

Fig. 2 is the endoscope lens diagrammatic cross-section that the utility model embodiment 1 arrives embodiment 3.

Fig. 3 is the transmission function figure of the utility model embodiment 1.

Fig. 4 is the curvature of field and distortion figure of the utility model embodiment 1.

Fig. 5 is the transmission function figure of the utility model embodiment 2.

Fig. 6 is the curvature of field and distortion figure of the utility model embodiment 2.

Fig. 7 is the transmission function figure of the utility model embodiment 3.

Fig. 8 is the curvature of field and distortion figure of the utility model embodiment 3.

Fig. 9 is the transmission function figure of the utility model embodiment 4.

Figure 10 is the curvature of field and distortion figure of the utility model embodiment 4.

Wherein, L1, the first lens；L2, the second lens；CF, optical filter；AS, aperture diaphragm；L3, the 3rd lens；L4, Four lens；CG, watch crystal；IMG, photosurface.

Embodiment

The embodiment to the technical solution of the utility model is described in detail below in conjunction with the accompanying drawings：

According to one embodiment of the application, as shown in figure 1, the fully separating formula endoscope lens of this programme, including from thing Side rise successively by the first lens L1, the second lens L2, optical filter CF, aperture diaphragm AS, the 3rd lens L3, the 4th lens L4 and Image sensor element is constituted.

First lens L1 is that thing flank radius is more than image side curvature radius, and concave surface thereon is towards image side surface Negative lens, the second lens L2 is that thing flank radius is less than image side curvature radius, and thereon convex surface facing thing side Positive lens, the 3rd lens L3 is positive lens, and the 4th lens L4 is that thing flank radius is less than image side curvature radius, and thereon Concave surface towards thing side negative lens, image sensor element by close to the 4th lens L4 watch crystal CG and photosurface IMG Composition.

For incidence angle of the reduction light on each optical surface, good, the fully separating formula of Folerances of Optical Elements characteristic is kept Endoscope lens meet all following conditionals (1)-(3),

-1.0<f1/f<-0.9 (1)

1.1<f12/f34<2.1 (2)

-1.1<f4/f<-0.9 (3)

Wherein f is object lens whole focal length, and f1 is the first lens L1 focal length, and f12 is the first lens L1 and the second lens L2 Combined focal length, f34 be the 3rd lens L3 and the 4th lens L4 combined focal lengths, f4 be the 4th lens L4 focal length.Peeped due to interior Imaging is usually required that apart from optical system 3mm-100mm in mirror, it is therefore desirable to destroy the symmetry of camera lens to a certain extent, and Beyond above-mentioned condition (1)-(3) aberrations such as optical system spherical aberration, astigmatism, the curvature of field can be caused to be difficult to offset, while also can easily lead Optical lens is caused easily to be influenceed by optics manufacturing tolerance.

In order to realize big visual angle, the first lens L1 and the second lens L2 meet all following conditionals (4)-(5),

0.4<d2/(n2*d3)<0.6 (4)

-0.7<r2/r3<-0.4 (5)

Wherein d2 is the thickness of airspace between the first lens L1 and the second lens L2, and d3 is the second lens L2 axially thick Degree, n2 is refractive indexes of the second lens L2 under d light (587.5nm), and r2 is the first lens L1 concave curvature radiuses, and r3 is second Lens L2 convex radius.

Due to meeting the condition of ultra-wide angle, the first lens L1 can produce substantial amounts of astigmatism and the curvature of field, the pact in condition (4) Under beam, the first lens L1 astigmatism and the curvature of field can be greatly lowered in the second lens L2, and light can be reduced by further meeting condition (5) Line the second lens L2 surfaces incident angle, and then reduce aberration balancing difficulty.

In order to further balance the aberration of each optical element, aperture diaphragm AS, the second lens L2 and the 3rd lens L3 are met All following condition formulaes (6)

1.1<Tf/Tb<1.4 (6)

Wherein Tf be aperture diaphragm AS things side to the second lens L2 image side surfaces airequivalent thickness, Tb is aperture diaphragm AS image side surfaces in the presence of condition (6), make optical filter CF excessive to the airequivalent thickness of the 3rd lens L3 things side Deviation symmetrical structure, meanwhile, optical filter CF filters out the infrared light into optical system, so as to lift picture contrast, optimizes Picture quality.

In following embodiment, r represents radius of curvature, and d represents face interval, and nd represents d light (587.5nm) refraction Rate, vd represents d light (587.5nm) Abbe number, and OBJ represents object plane, and IMA represents image planes, and STO represents aperture diaphragm AS, FNO table Show optical system F numbers, f is optical lens focal length.

Embodiment 1：

As in Figure 2-4, in the present embodiment, f1/f=-0.906, f12/f34=1.188, f4/f=-0.9, d2/ (n2* D3)=0.539, r2/r3=-0.615, Tf/Tb=1.221.

Wherein f is object lens whole focal length, and f1 is the first lens L1 focal length, and f12 is the first lens L1 and the second lens L2 Combined focal length, f34 be the 3rd lens L3 and the 4th lens L4 combined focal lengths, f4 be the 4th lens L4 focal length, d2 is first The thickness of airspace between lens L1 and the second lens L2, d3 is the second lens L2 axial widths, and n2 is the second lens L2 in d light Refractive index under (587.5nm), Tf is airequivalent thickness of the aperture diaphragm AS things side to the second lens L2 image side surfaces, and Tb is Airequivalent thickness of the aperture diaphragm AS image side surfaces to the 3rd lens L3 things side.

Each data of gained are as follows：

FNO=7.2, f=0.999

Fig. 3 is the utility model optical system transfer function figure, it is seen that each visual field transfer curve TS is with shown in figure Diffraction limit Diff.Limit is approached, with good picture matter.

Fig. 4 is the utility model optical system curvature of field (Field Curvature) and distorts (Distortion), can by figure The utility model optical system curvature of the image is known within 0.05mm, meets image quality requirement, simultaneously because big visual field Under the conditions of, big pattern distortion is also acceptable.

Embodiment 2

As shown in Figure 2, Figure 5 and Figure 6, in the present embodiment, f1/f=-0.946, f12/f34=1.522, f4/f=- 1.021, d2/ (n2*d3)=0.463, r2/r3=-0.414, Tf/Tb=1.352.

Each data of gained are as follows：

FNO=7.0, f=0.958

Fig. 5 is the utility model optical system transfer function figure, it is seen that each visual field transfer curve TS is with shown in figure Diffraction limit Diff.Limit is approached, with good picture matter.

Fig. 6 is the utility model optical system curvature of field (Field Curvature) and distorts (Distortion), can by figure The utility model optical system curvature of the image is known within 0.05mm, meets image quality requirement, simultaneously because big visual field Under the conditions of, big pattern distortion is also acceptable.

Embodiment 3

As shown in Fig. 2, Fig. 7 and Fig. 8, in the present embodiment, f1/f=-0.949, f12/f34=2.096, f4/f=- 0.991, d2/ (n2*d3)=0.463, r2/r3=-0.450, Tf/Tb=1.774.

Each data of gained are as follows：

FNO=7.3, f=0.970

Fig. 7 is the utility model optical system transfer function figure, it is seen that each visual field transfer curve TS is with shown in figure Diffraction limit Diff.Limit is approached, with good picture matter.

Fig. 8 is the utility model optical system curvature of field (Field Curvature) and distorts (Distortion), can by figure The utility model optical system curvature of the image is known within 0.05mm, meets image quality requirement, simultaneously because big visual field Under the conditions of, big pattern distortion is also acceptable.

Embodiment 4

As shown in Fig. 2, Fig. 9 and Figure 10, in the present embodiment, f1/f=-0.954, f12/f34=2.018, f4/f=- 0.993, d2/ (n2*d3)=0.463, r2/r3=-0.445, Tf/Tb=1.756.

Each data of gained are as follows：

FNO=6.8, f=0.964

Fig. 9 is the utility model optical system transfer function figure, it is seen that each visual field transfer curve TS is with shown in figure Diffraction limit Diff.Limit is approached, with good picture matter.

Figure 10 is the utility model optical system curvature of field (Field Curvature) and distortion (Distortion), by scheming The utility model optical system curvature of the image is understood within 0.05mm, image quality requirement is met, simultaneously because big visual field Under conditions of, big pattern distortion is also acceptable.

Although being described in detail with reference to accompanying drawing to the embodiment of utility model, it should not be construed as to this The restriction of the protection domain of patent.In the scope described by claims, those skilled in the art are without creative work The various modification and variation that can be made still belong to the protection domain of this patent.

Claims

1. a kind of fully separating formula endoscope lens, it is characterised in that：Including be sequentially connected from object side the first lens, second Lens, optical filter, aperture diaphragm, the 3rd lens, the 4th lens and image sensor element；

3rd lens are positive lens；

The fully separating formula endoscope lens meet following conditions：

-1.0<f1/f<-0.9

1.1<f12/f34<2.1

-1.1<f4/f<-0.9

Wherein, f is object lens whole focal length, and f1 is the focal length of the first lens, and f12 is combination Jiao of the first lens and the second lens Away from f34 is the 3rd lens and the 4th lens combination focal length, and f4 is the focal length of the 4th lens.

2. fully separating formula endoscope lens according to claim 1, it is characterised in that：First lens and the second lens Meet following conditions：

0.4<d2/(n2*d3)<0.6

-0.7<r2/r3<-0.4

Wherein, d2 is the thickness of airspace between the first lens and the second lens, and d3 is the second lens axial width, and n2 is second Refractive index of the lens under d light, r2 is the first concave lens surface radius of curvature, and r3 is the second convex lens surface radius of curvature.

3. fully separating formula endoscope lens according to claim 2, it is characterised in that：The a length of 587.5nm of d light waves.

4. fully separating formula endoscope lens according to claim 1, it is characterised in that：The aperture diaphragm, the second lens Following condition is met with the 3rd lens

1.1<Tf/Tb<1.4

Wherein, Tf is airequivalent thickness of the aperture diaphragm thing side to the second lens image side surface, and Tb is aperture diaphragm image side surface To the airequivalent thickness of the 3rd lens thing side.

5. fully separating formula endoscope lens according to claim 1, it is characterised in that：Described image sensing element is by close Watch crystal and the photosurface composition of 4th lens.