CN112137577A

CN112137577A - Fundus imaging lens, fundus camera and fundus imaging method

Info

Publication number: CN112137577A
Application number: CN202011142661.XA
Authority: CN
Inventors: 王瑞
Original assignee: Suzhou Yinquepi Electronic Technology Co ltd
Current assignee: Suzhou Yinquepi Electronic Technology Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2020-12-29

Abstract

The invention discloses a fundus imaging lens, which comprises a retina objective lens, a diaphragm, an illumination light source, a relay lens and a vision fixing module, wherein illumination light emitted by the illumination light source forms a first imaging surface and a second imaging surface through the retina objective lens, an eye and the relay lens, and the vision fixing module is arranged near the first imaging surface or the second imaging surface. When the vision fixing module is arranged near the first imaging surface, at least one relay lens in the vision fixing module and the relay lens can move along the main optical axis; when the fixation module is arranged near the secondary imaging surface, at least one relay lens in the relay lens can move along the main optical axis, and a polarizer and an analyzer are arranged in the fixation module. The invention also discloses an eye fundus camera, an eye fundus imaging lens and an image sensing module. The invention also discloses a fundus imaging method which is realized by adopting the fundus imaging lens.

Description

Fundus imaging lens, fundus camera and fundus imaging method

Technical Field

The invention relates to the technical field of fundus cameras, in particular to a fundus imaging lens, a fundus camera and a fundus imaging method.

Background

The fundus camera is a device for inspecting the fundus of an eyeball by fundus imaging, and the basic principle is to introduce a light source into the fundus of the eyeball to be observed, and then image the fundus on a photosensitive component of the camera through an imaging structure, wherein the fundus camera can shoot a picture or a video of the fundus for storage and analysis. The fundus camera consists of a fundus imaging lens and an image sensing module.

In the related art, in order to guide the eyeball of the observed person to focus in a prescribed distance and direction, a method of providing a fixation screen in a fundus camera and imaging the fixation screen to the fundus by providing an optical element is generally adopted. For example, in an invention entitled adaptive optical fundus camera with visibility adjustment (publication No. CN103271717A), a structure is disclosed in which a bypass optical path is branched from a fundus imaging optical path of the fundus camera, and a lens device and a fixation screen are added to the bypass optical path, so as to image the fixation screen onto the fundus.

In response to the above problems, some portable fundus cameras have appeared in the art. The existing portable fundus camera usually adopts a scheme that a vision fixing module consisting of a beam splitter and a vision fixing screen is arranged near a first imaging surface or a second imaging surface of the fundus, so that the vision fixing screen and the fundus image surface form a conjugate relation.

Specifically, the invention named as a lens module and a fundus camera (publication No. CN103926679A) adopts a scheme in which a fixation module is provided near a first-time imaging plane. Due to the diopter difference of eyes (for example, the diopter difference between a myope and a hyperopic patient is large), the position of the first imaging surface of the fundus imaged by the retinal objective can change with different diopters to a large extent. Therefore, the scheme only aims at eyes with a certain diopter value, and realizes the conjugation of the fixation screen and the first imaging plane. When eyes with different diopters are imaged, the fixation screen and the first imaging surface are not conjugated any more, namely the fixation screen and the second imaging surface are not conjugated any more. At the moment, the secondary imaging surface is accurately superposed with the image sensing module of the camera, and the secondary imaging surface and the eye can not see a clear fixation screen at the same time. It can be seen that the fixation module in this solution cannot accurately guide the focusing of the fundus camera for eyes of different diopters.

The invention entitled fundus camera (publication No. CN105581771A) adopts a scheme in which a fixation module is provided near the secondary imaging surface. Compared with the first scheme, the scheme only needs to keep the relative position of the fixation module and the image sensing module fixed, the fixation screen can always keep a conjugate relation with the second imaging surface, and focusing of the fundus camera is guided through the fixation module. However, the scheme also has a certain defect that because the vision fixing module is close to the image sensing module, light emitted by the vision fixing screen is reflected by the adjacent lens to form ghost images and stray light, and the quality of the shot images is seriously affected.

In summary, the existing technical solutions in the art cannot simultaneously satisfy the requirements of convenient operation, portability, precise focusing and high-quality shooting. The existing fundus imaging lens, fundus camera and fundus imaging method have larger lifting space.

Disclosure of Invention

In view of the above, the present invention provides a fundus imaging lens, which can precisely guide focusing without adding a side branch optical path for eyes with different diopters, and can effectively eliminate ghost images and stray light, thereby improving the quality of the captured images.

Another object of the present invention is to provide a fundus camera to which the fundus imaging lens is applied, which effectively reduces the volume while ensuring the quality of the photographed image.

Another object of the present invention is to provide a fundus imaging method, which improves the convenience and accuracy of operation by adjusting the fundus imaging lens.

In order to achieve the above object, the present invention provides a fundus imaging lens, comprising a retinal objective lens, a diaphragm, a lighting source, a relay lens and a fixation module, wherein the retinal objective lens, the diaphragm and the relay lens are arranged in sequence along an optical axis, and the optical axis is a main optical axis; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the relay lens comprises at least one relay lens capable of moving along the direction of a main optical axis, and the vision fixing module is arranged between the retina objective lens and the first imaging surface and capable of moving along the main optical axis.

Preferably, the relay lens is linked with the vision fixing module.

The invention provides a fundus camera which comprises a fundus imaging lens and an image sensing module, wherein the image sensing module is arranged at the second imaging surface.

The invention provides a fundus imaging method, which adopts the fundus imaging lens and comprises the following steps:

(A) operating the fundus imaging lens to align with the eye;

(B) and adjusting the relay lens and the vision fixing module to perform linkage focusing.

The invention provides a fundus imaging lens, which comprises a retina objective lens, a diaphragm, an illumination light source, a relay lens and a fixation module, wherein the retina objective lens, the diaphragm and the relay lens are sequentially arranged along an optical axis, and the optical axis is a main optical axis; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the relay lens comprises at least one relay lens capable of moving along the direction of a main optical axis, and the vision fixing module is positioned between the relay lens and the second imaging surface; the module of looking admittedly is including looking admittedly screen, beam splitter, polarizer and analyzer, admittedly look the screen optical axis with the primary optical axis sets up perpendicularly, the beam splitter optical axis with the primary optical axis reaches admittedly look screen optical axis coplane, just the beam splitter optical axis with the primary optical axis is 45 jiaos of settings, the polarizer sets up admittedly look the screen with between the beam splitter, just the polarizer with admittedly look screen parallel arrangement, the analyzer sets up the beam splitter rear portion, just the analyzer with the primary optical axis is coaxial.

(A) operating the fundus imaging lens to align with the eye;

(B) and adjusting the relay lens to focus.

The invention provides an eyeground camera, which comprises an eyeground imaging lens and an image sensing module, wherein the eyeground imaging lens comprises a retinal objective lens, a diaphragm, an illumination light source, a relay lens and a fixation module; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the vision fixing module is positioned between the relay lens and the second imaging surface; the fixation module comprises a fixation screen, a beam splitter, a polarizer and an analyzer, wherein the optical axis of the fixation screen is perpendicular to the main optical axis, the optical axis of the beam splitter is coplanar with the main optical axis and the optical axis of the fixation screen, the optical axis of the beam splitter and the main optical axis are arranged at an angle of 45 degrees, the polarizer is arranged between the fixation screen and the beam splitter and is arranged in parallel with the fixation screen, the analyzer is arranged at the rear part of the beam splitter, and the analyzer and the main optical axis share the optical axis; the image sensing module is arranged at the second secondary imaging surface; the image sensing module can move along the direction of the main optical axis, the fixation module can move along the direction of the main optical axis, and the fixation module and the image sensing module move synchronously and have the same track.

The invention provides a fundus imaging method, which adopts the fundus camera and comprises the following steps:

(A) operating the fundus imaging lens to align with the eye;

(B) and synchronously adjusting the vision fixation module and the image sensing module to focus.

Preferably, the fixation module comprises a fixation screen with a plurality of sub-regions thereon.

Preferably, the illumination light source is composed of a combination of a near-infrared light source and a white light source.

Preferably, the omentum objective comprises at least one objective lens; when the omentum objective lens comprises one objective lens, at least one surface of the objective lens is an aspheric surface; when the omentum objective lens comprises at least two objective lenses, the objective lenses form a multi-cemented lens, and at least one surface of the multi-cemented lens is an aspheric surface.

Preferably, the diaphragm is provided with a circular light through hole in the middle, the illumination light source comprises a plurality of white light sources and a plurality of near-infrared light sources, the white light sources and the near-infrared light sources are uniformly mixed to form an annular arrangement, and the illumination light sources are arranged close to the diaphragm.

Compared with the prior art, the fundus imaging lens, the fundus camera and the fundus imaging method disclosed by the invention have the advantages that: the fundus imaging lens can be suitable for imaging of eyes with different diopters, and is high in focusing accuracy and good in imaging quality; the fundus imaging lens filters most cornea reflected light by setting the illumination light to be reflected by the cornea at a large angle relative to the optical axis, and filters residual ghost images and stray light introduced by the illumination light through the diaphragm, so that the image quality is further improved; by forming a plurality of sub-regions on the fixation screen, the fundus imaging field of view is increased; the eye ground camera is convenient to operate and carry, and a photographed person can finish photographing operation by himself; the fundus imaging method is convenient to operate and high in accuracy.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings 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 some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a fundus imaging lens according to a first preferred embodiment of the present invention.

Fig. 2 is a schematic structural view of a fundus camera according to a first preferred embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a fundus imaging lens according to a second preferred embodiment of the present invention.

Fig. 4 is a schematic structural view of a fundus camera according to a second preferred embodiment of the present invention.

Fig. 5 is a schematic structural view showing a modification of the second preferred embodiment of the fundus camera according to the present invention.

Fig. 6 is a schematic structural diagram of a view fixing screen of a fundus imaging lens according to the present invention.

Fig. 7 is a diagram showing the optical path of illumination light emitted by the illumination light source of the fundus imaging lens according to the present invention.

Fig. 8 is a diagram showing an optical path of illumination light emitted from an illumination light source of a fundus camera according to the present invention.

Fig. 9 is a schematic structural diagram of the illumination light source.

Fig. 10 is a schematic diagram showing the illumination effect formed by the illumination light source on the fundus.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a fundus imaging lens 10 according to a first preferred embodiment of the present invention includes a retinal lens 11, a diaphragm 12, an illumination light source 13, a relay lens 14, and a fixation module 30. The omentum objective lens 11, the diaphragm 13 and the relay lens 14 are sequentially arranged with an optical axis, wherein the optical axis is a main optical axis. The illumination source 13 is arranged on the side of the diaphragm 12 facing the retinal objective 11, the retinal objective 11 being arranged in alignment with the eye 4. The illumination light emitted by the illumination light source 13 is incident on the eye 4 through the retina objective lens 11, the illumination light is projected to the fundus of the eye, the fundus generates reflected light and emits from the eye, the reflected light images the fundus image on the first secondary imaging surface I1 after passing through the retina objective lens 11, and the reflected light continues to image the first secondary imaging surface I1 on the second secondary imaging surface I2 through the relay lens 14. The relay lens 14 includes at least one relay lens, and the at least one relay lens is movable along the main optical axis direction. The vision fixation module 30 is disposed between the retinal objective lens 11 and the first primary imaging surface I1, and the vision fixation module 30 is movable in the main optical axis direction.

Specifically, the fixed-view module 30 includes a fixed-view screen 31 and a beam splitter 32, an optical axis of the fixed-view screen 31 is perpendicular to the main optical axis, an optical axis of the beam splitter 32 is coplanar with the main optical axis and the fixed-view screen optical axis 31, and the optical axis of the beam splitter 32 and the main optical axis are arranged at an angle of 45 °.

The retinal objective lens 11 includes at least one objective lens. Preferably, the retinal objective lens 11 includes a biconvex aspheric objective lens, and at least one surface of the objective lens is aspheric. Preferably, the retinal objective has as few lens-air interfaces as possible, such as: the omentum objective lens is an aspheric lens; alternatively, the retinal objective lens is a piece of cemented doublet or cemented multiply lens that includes an aspheric surface. This arrangement can reduce ghost images and stray light caused by reflection from the surfaces of the mesh objective lens while eliminating a part of the phase difference.

At least one relay lens in the relay lens 14 can move along the main axis direction, and the relay lens can be adjusted to focus for eyes 4 with different diopters. In addition, since the vision fixing module 30 is located near the first imaging surface I1 in this embodiment, when the eyes with different diopters are imaged, the first imaging surface I1 may shift, and when the relay lens is adjusted, the vision fixing module 30 needs to be adjusted at the same time to compensate the diopters. Preferably, a movable relay lens can be arranged to be linked with the fixation module 30 to ensure that the fixation module 30 and the first imaging plane I1 always keep a conjugate relationship to ensure accurate focusing when the eye is gazing at the fixation screen 31. It should be noted that the movement tracks of the relay lens and the fixation module 30 are different, and need to have an accurate functional relationship with each other. For example, a mechanical transmission structure such as a cam can be used to realize the relay lens and the fixation module 30 to be linked in a precise functional relationship. The focus adjustment may take a manual or motorized form. When the relay lens and fixation module 30 is adjusted in an electric manner, an electric motor, a voice coil motor, an ultrasonic motor, or the like may be used to drive the relay lens and fixation module. If two motors are adopted to drive the relay lens and the fixation module respectively, the precise functional relation between the moving tracks of the relay lens and the fixation module can be realized under the condition that mechanical transmission structures such as a cam and the like are not needed. Adopt electronic form to adjust relay lens and solid module of looking, the operation is convenient and fast more.

As shown in FIG. 2, a fundus camera 1 according to a first preferred embodiment of the present invention includes the fundus imaging lens 10 and the image sensing module 20, and the image sensing module 20 is disposed at the second sub-imaging plane I2. The image sensing module 20 includes a circuit substrate 21 and an image sensor 22, the image sensor 22 is mounted on the circuit substrate 21, and the image sensor 22 is located at the second secondary imaging plane I2. Further, the image sensing module 20 and the fixation module 30 may be configured to be linked, and the image sensing module 20 and the fixation module 30 may be driven to move manually or electrically.

In a first preferred embodiment, the present invention provides a fundus imaging method, comprising the steps of:

(A) operating the fundus imaging lens to align with the eye;

Fig. 3 shows a second preferred embodiment of a fundus imaging lens according to the present invention, which is different from the first preferred embodiment in the vision fixation module. The vision fixation module 30A in the second preferred embodiment is located between the relay lens 14 and the second secondary imaging plane I2. The fixation module 30A includes a fixation screen 31A and a beam splitter 32A, an optical axis of the fixation screen 31A is perpendicular to the main optical axis, the optical axis of the beam splitter 32A is coplanar with the main optical axis and the fixation screen optical axis 31A, and the optical axis of the beam splitter 32A and the main optical axis are arranged at an angle of 45 °. The relay lens 14 includes at least one relay lens, and at least one relay lens can move along the main optical axis direction, and the fixation module 30A is fixed. By moving the relay lens, the vision fixing screen 31A and the second-time imaging plane I2 can be kept in a conjugate relationship without moving the vision fixing module 30A.

Referring to fig. 4, a fundus camera 1 according to a second preferred embodiment of the present invention includes the fundus imaging lens 10 and the image sensing module 20, and the image sensing module 20 is disposed at the second sub-imaging plane I2. Since the fixed-view module 30A is adjacent to the image sensing module 20, in order to solve the problem of ghost and stray light reflected by the fixed-view light, the fixed-view module 30A further includes a polarizer 301A and an analyzer 302A, the polarizer 301A is disposed between the fixed-view screen 31A and the beam splitter 32A, the polarizer 301A is disposed parallel to the fixed-view screen 31A, the analyzer 302A is disposed between the beam splitter and the image sensing module 20, and the analyzer 302A is coaxial with the main optical axis. The fixed vision light emitted by the fixed vision screen 31A is polarized through the polarizer 301A, the polarization direction is horizontal or vertical after being reflected by the beam splitter 32A, and the direction of the analyzer 302A is set so that the analyzer only allows the polarized light in the vertical or horizontal direction to penetrate through, so that the fixed vision light reflected by the relay lens 14 and the like can be filtered by the analyzer 302A, the purpose of inhibiting ghost images and stray light introduced by the fixed vision light is achieved, and the image quality is effectively improved.

In a second preferred embodiment, the present invention provides a fundus imaging method, comprising:

(C) operating the fundus imaging lens to align with the eye;

(D) and adjusting the relay lens to focus.

Fig. 5 shows a variation of the second preferred embodiment of the fundus camera of the present invention, in which the relay lens 14 is fixed and the image sensing module 20 can move along the direction of the main optical axis to realize focusing. Accordingly, in this variant, it is required to provide that the fixation module 30A can move along the main optical axis direction, and the fixation module 30A and the image sensing module 20 move synchronously and have the same track, so as to ensure that the fixation screen 31A and the second secondary imaging surface I2 keep a conjugate relationship. Preferably, the fixation module 30A is fixedly connected with the image sensing module 20, and the fixation module 30A and the image sensing module 20 are moved synchronously during focusing, so that the fixation screen 31A and the second imaging plane I2 are kept in a conjugate relationship, and the operation is more convenient.

In a second preferred embodiment, the present invention provides a method for fundus imaging, comprising the steps of:

(C) operating the fundus imaging lens to align with the eye;

(D) and synchronously adjusting the vision fixation module and the image sensing module to focus.

Being applicable to above-mentioned embodiment and embodiment variant, can setting up to have a plurality of subregions on the fixation screen 31, when eyes stare at different subregions on the fixation screen 31, eyes can spontaneous rotation to corresponding angle to can image the fundus corresponding position, conveniently realize imaging the region that the focus needs to observe to the fundus, and can indirectly realize the purpose in increase fundus formation of image visual field. In order to divide the sub-areas on the fixed view screen 31, various modes can be adopted, an array or a pattern formed by various light sources can be arranged on the fixed view screen 31, an array or a pattern formed by a plurality of lamp beads (such as halogen tungsten lamps, xenon lamps, LEDs, Vcsel and the like) can be arranged, a reticle illuminated by the light sources can be arranged, a simple display device such as a digital tube can be adopted, or various display screens such as a liquid crystal display screen, an LCOS, an LED, an OLED and the like can be adopted.

Specifically, as shown in fig. 6, the fixation screen 31 has 9 circles 311 distributed around it, and when the eye gazes at the middle circle, an image of the middle of the fundus is captured, and when the eye gazes at the surrounding circle, an image of the periphery of the fundus is captured.

As shown in fig. 7 and 8, the illumination light source 13 is located on one side of the main optical axis, and the illumination light emitted by the illumination light source 13 illuminates the cornea on the other side of the main optical axis through the convergent light formed by the retinal objective lens 11, and the light reflected by the cornea is reflected at a large angle deviating from the main optical axis and is not reflected into the retinal objective lens 11, so that the influence of the corneal reflection light is prevented, and ghost images and stray light caused by the corneal reflection light are eliminated. Further, since the cornea is close to the pupil and the illumination light source 13 is imaged near the pupil, the illuminated surface of the cornea passes through the position of the image made by the retinal objective lens 11 and is also near the illumination light source 13. Therefore, a further diaphragm 12 is arranged next to the illumination light source 13 to filter the residual illumination light reflected by the cornea entering the retinal objective 11. The stop 12 can also suppress ghost images and stray light formed by other eye tissues outside the cornea and by reflection of the illumination light source 13 by the retinal objective lens 11.

The illumination light source 13 has at least one color. Preferably, the illumination light source 13 may employ near infrared light. Because human eyes are not sensitive to near infrared light, pupils cannot be closed, and the injury to the human eyes is small, the near infrared light is preferably adopted as an illuminating light source for previewing imaging; the near infrared light can work in a continuous state, the dynamic video of the eyeground can be shot in real time, and the focusing operation can be realized. Preferably, the illumination light source 13 may employ white light. Because human eyes are sensitive to white light and pupils can contract, pulse type white light illumination can be adopted during white light illumination, and the color of a high-resolution color image is shot in a time period when the pupils are not close to the contraction time period so as to cooperate with medical diagnosis. Preferably, the illumination light source 13 is configured by matching near-infrared light and white light, and when imaging, continuous near-infrared illumination is firstly used for preview and focusing, and when focusing is clear, a high-resolution image is captured by using pulsed white light.

Specifically, the illumination light source 13 and the diaphragm 12 are preferably configured as shown in fig. 9, the diaphragm 12 has a circular light-passing hole 121 in the middle, and the diaphragm 12 is opaque except for the light-passing hole 121. The illumination light source 13 includes a plurality of white light sources 131 and a plurality of near infrared light sources 132, and the white light sources 131 and the near infrared light sources 132 are uniformly mixed to form a ring-shaped arrangement. The illumination source 13 is located next to the diaphragm 12, preferably the illumination source 13 is fixed to the diaphragm 12.

The illumination effect of the illumination light source 13 on the fundus is shown in fig. 10. Each light source forms an illumination spot on the fundus, and the uniform illumination field can be obtained by the superposition effect of the spot intensities of a plurality of light sources. By increasing the number of light sources and increasing the diameter ratio of the illumination spots of a single light source relative to the diameter of the circle in which the centers of the spots are located, the resulting illumination uniformity can be further increased.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fundus imaging lens is characterized by comprising a mesh lens, a diaphragm, an illumination light source, a relay lens and a fixation module, wherein the mesh lens, the diaphragm and the relay lens are sequentially arranged along an optical axis, and the optical axis is a main optical axis; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the relay lens comprises at least one relay lens capable of moving along the direction of a main optical axis, and the vision fixing module is arranged between the retina objective lens and the first imaging surface and capable of moving along the main optical axis.

2. A fundus imaging lens according to claim 1, wherein said relay lens is linked with said vision fixation module.

3. A fundus camera comprising the fundus imaging lens of claim 1 and an image sensing module disposed at the second secondary imaging surface.

4. A fundus imaging method according to claim 2, wherein the fundus imaging lens is used, comprising the steps of:

(A) operating the fundus imaging lens to align with the eye;

5. A fundus imaging lens is characterized by comprising a mesh lens, a diaphragm, an illumination light source, a relay lens and a fixation module, wherein the mesh lens, the diaphragm and the relay lens are sequentially arranged along an optical axis, and the optical axis is a main optical axis; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the relay lens comprises at least one relay lens capable of moving along the direction of a main optical axis, and the vision fixing module is positioned between the relay lens and the second imaging surface; the module of looking admittedly is including looking admittedly screen, beam splitter, polarizer and analyzer, admittedly look the screen optical axis with the primary optical axis sets up perpendicularly, the beam splitter optical axis with the primary optical axis reaches admittedly look screen optical axis coplane, just the beam splitter optical axis with the primary optical axis is 45 jiaos of settings, the polarizer sets up admittedly look the screen with between the beam splitter, just the polarizer with admittedly look screen parallel arrangement, the analyzer sets up the beam splitter rear portion, just the analyzer with the primary optical axis is coaxial.

6. A fundus camera comprising the fundus imaging lens of claim 5 and an image sensing module disposed at the second secondary imaging surface.

7. A fundus imaging method according to claim 5, wherein the fundus imaging lens is used, comprising the steps of:

(A) operating the fundus imaging lens to align with the eye;

(B) and adjusting the relay lens to focus.

8. An eye fundus camera is characterized by comprising an eye fundus imaging lens and an image sensing module, wherein the eye fundus imaging lens comprises a mesh film objective lens, a diaphragm, an illuminating light source, a relay lens and a fixation module, the mesh film objective lens, the diaphragm and the relay lens are sequentially arranged along the same optical axis, and the optical axis is a main optical axis; the omentum objective lens is aligned with the eye; illuminating light emitted by the illuminating light source is incident to the eye through the retina objective lens, the illuminating light is projected to the fundus of the eye, reflected light generated by the fundus is emitted from the eye, the reflected light is imaged on a first imaging surface after passing through the retina objective lens, and the reflected light continues to pass through the relay lens to image the first imaging surface on a second imaging surface; the vision fixing module is positioned between the relay lens and the second imaging surface; the fixation module comprises a fixation screen, a beam splitter, a polarizer and an analyzer, wherein the optical axis of the fixation screen is perpendicular to the main optical axis, the optical axis of the beam splitter is coplanar with the main optical axis and the optical axis of the fixation screen, the optical axis of the beam splitter and the main optical axis are arranged at an angle of 45 degrees, the polarizer is arranged between the fixation screen and the beam splitter and is arranged in parallel with the fixation screen, the analyzer is arranged at the rear part of the beam splitter, and the analyzer and the main optical axis share the optical axis; the image sensing module is arranged at the second secondary imaging surface; the image sensing module can move along the direction of the main optical axis, the fixation module can move along the direction of the main optical axis, and the fixation module and the image sensing module move synchronously and have the same track.

9. A fundus imaging method according to claim 8, characterized by using the fundus camera, comprising the steps of:

(A) operating the fundus imaging lens to align with the eye;

10. An fundus imaging lens according to any one of claims 1, 2 or 5, wherein said fixation module comprises a fixation screen having a plurality of sub-regions thereon.

11. An fundus imaging lens according to any of claims 1, 2 and 5 wherein said illumination light source is constituted by a combination of a near infrared light source and a white light source.

12. An fundus imaging lens according to any of claims 1, 2 or 5 wherein said retinal objective comprises at least one objective lens; when the omentum objective lens comprises one objective lens, at least one surface of the objective lens is an aspheric surface; when the omentum objective lens comprises at least two objective lenses, the objective lenses form a multi-cemented lens, and at least one surface of the multi-cemented lens is an aspheric surface.

13. The fundus imaging lens according to any one of claims 1, 2 and 5, wherein a circular light through hole is formed in the middle of the diaphragm, the illumination light source comprises a plurality of white light sources and a plurality of near infrared light sources, the white light sources and the near infrared light sources are uniformly mixed to form an annular arrangement, and the illumination light source is arranged close to the diaphragm.