CN216823416U

CN216823416U - Contact type fundus camera illumination light path system

Info

Publication number: CN216823416U
Application number: CN202123325105.9U
Authority: CN
Inventors: 余文超; 陶钧
Original assignee: Chongqing Bio Newvision Medical Equipment Ltd
Current assignee: Chongqing Bio Newvision Medical Equipment Ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-06-28
Anticipated expiration: 2031-12-27

Abstract

The utility model discloses a contact eye ground camera illumination light path system, including light source, big objective group, aperture diaphragm, formation of image mirror group and image acquisition device, the annular light source that the light source is enclosed by many LED lamps, annular light source arranges around the formation of image light path, big objective group comprises at least three big thing lens, its characterized in that: all the large objective lenses of the large objective lens group are glued together, films are coated on the gluing surfaces of the large objective lenses, the position of the LED lamp is conjugated with the pupil, an anti-impurity diaphragm for an imaging light path to pass through is arranged on the convex surface of the large objective lens close to the light source, the anti-impurity diaphragm is a black shading cylinder, and imaging light rays coming out of the pupil reach the imaging lens group after passing through the large objective lens group, the anti-impurity diaphragm and the aperture diaphragm. Reasonable in design, simple structure can effectively avoid lens and iris reflection parasitic light, reduces the influence to the parasitic light to the formation of image.

Description

Contact type fundus camera illumination light path system

Technical Field

The utility model relates to a contact eye ground camera illumination optical path system belongs to optics technical field.

Background

Wide area fundus imaging, generally used at home and abroad, is to install an illuminating lamp at a distance of about 10mm outside the eye, which can illuminate the fundus, but when the light is transmitted to the pupil, the beam diameter is larger, generally more than 5mm, due to the field angle.

The existing fundus camera optical paths are especially numerous, and for a contact type fundus camera (pupils are directly contacted with lenses and are mainly used for infants), the fundus camera optical paths are represented by Wenshensi and Retcam which are foreign countries and domestic Tianjin Soviet dimensional. They have in common that the light path of illumination is shaped by adding an LED lamp group at a place short of eyes to directly irradiate the eyes: the resulting problem is that at the location of the pupil, the light is relatively diffuse producing veiling glare. Since neither of these illuminations is conjugate, i.e., the bulb position is not conjugate to the pupil position. Since the non-conjugate relationship always exists, the light irradiating the fundus oculi easily irradiates the iris to generate the reflected stray light. Meanwhile, the lens (large objective lens) itself can reflect a large amount of stray light to enter the image acquisition device.

SUMMERY OF THE UTILITY MODEL

To the above technical problem, an object of the utility model is to provide a contact eye ground camera illumination optical path system reduces the lens and reflects the parasitic light, shines evenly, reduces the iris and reflects the parasitic light.

In order to realize the purpose, the technical scheme of the utility model is that: a contact type fundus camera illumination light path system comprises a light source, a large objective lens group, an aperture diaphragm, an imaging lens group and an image acquisition device, wherein the light source is an annular light source formed by surrounding a plurality of LED lamps, the annular light source is arranged around an imaging light path, and the large objective lens group is composed of at least three large objective lenses, and is characterized in that: all the large objective lenses of the large objective lens group are sequentially glued together, the gluing surfaces of the large objective lenses are coated with films, and the positions of the LED lamps are conjugated with pupils. The coating increases its anti-reflective ability.

In the scheme, the method comprises the following steps: an anti-impurity diaphragm for an imaging light path to pass through is arranged on the convex surface of the large object lens close to the light source, the anti-impurity diaphragm is a black shading cylinder, and imaging light rays coming out of a pupil reach the imaging lens group after passing through the large objective lens group, the anti-impurity diaphragm and the aperture diaphragm. The stray light blocking plate can prevent stray light from mixing.

In the scheme, the method comprises the following steps: the big objective lens group consists of 6 big objective lenses.

In the scheme, the method comprises the following steps: the image acquisition device is a CCD camera or an outsourcing lens component.

In the scheme, the method comprises the following steps: the refractive indexes of the bonding materials of the bonding surfaces are arranged at intervals from high to low in sequence from the position close to the pupil to the position far away from the pupil.

Light rays generated by the LED annular lamp irradiate to the eyeground through the large objective lens group, and an eyeground imaging light path enters the imaging lens group after passing through the large objective lens group, the impurity-preventing diaphragm and the aperture diaphragm and then reaches the image acquisition device through the imaging lens group.

The utility model discloses paste three piece at least big objective lens, the equal coating film of cementing face, the coating film face can effectual reduction parasitic light's reflectivity, and the reflection parasitic light is little to 0.1%. The light reflected by the reflecting surface of the last large objective lens (the large objective lens close to the light source and the first surface irradiated by the LED lamp) is blocked by the stray light stop and cannot enter the imaging light path, so that the stray light reflected by the lens is further reduced,

because the position of the LED lamp and the pupil of the eye are in a conjugate relation on the light path, the light rays can form an intersection point at the pupil position. The illumination is uniform, and the iris can completely avoid reflecting stray light when the iris is illuminated at the pupil position. The position of the lamp is strictly conjugated with the pupil, so that the illuminating light is just converged together when passing through the pupil, is not conical and divergent like the current similar products at home and abroad, and is easy to irradiate the outside of the pupil to generate reflected stray light. The design uses the illumination principle, and is different from illumination at home and abroad. Illumination conjugated with the pupil is adopted, so that the diameter of the light beam within 2mm can be reached when the light is transmitted to the pupil.

The utility model discloses following beneficial effect has: the utility model relates to a rationally, simple structure can effectively avoid lens and iris reflection parasitic light, reduces the influence to the parasitic light to the formation of image.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic view of a light source structure.

Detailed Description

The invention will be further described by way of examples with reference to the accompanying drawings:

example 1

As shown in fig. 1 and 2, the contact type fundus camera illumination optical path system is composed of a light source 1, a large objective lens group 2, an aperture diaphragm 3, an imaging lens group 4, an image acquisition device 5 and an anti-contamination diaphragm 6.

The imaging lens group 4 is the prior art, and the image acquisition device 5 is a CCD camera or an outsourcing lens assembly.

The light source 1 is an annular light source surrounded by a plurality of LED lamps, and the annular light source is arranged around the imaging optical path as shown in fig. 2.

The large objective lens group 2 comprises at least three large objective lenses, in the figure, 6 large objective lenses, which are respectively a first lens 201, a second lens 202, a third lens 203, a fourth lens 204, a fifth lens 205 and a sixth lens 206, wherein the sixth lens 206 is close to the light source. All the large objective lenses of the large objective lens group 2 are sequentially glued together, and the gluing surfaces are coated with films, so that the anti-reflection capability is improved. The refractive indexes of the gluing materials of the gluing surfaces are arranged at intervals from high to low in sequence from the position close to the pupil to the position far away from the pupil, if the first gluing surface is the gluing material with low refractive index, the second gluing surface is the gluing material with high refractive index, and the third gluing surface is changed into the gluing material with low refractive index, the intervals are the same. The position of the LED lamps is conjugated (optically conjugated) with the pupil, i.e. all the LED lamps are on the conjugated surface of the pupil. An anti-stray light diaphragm 6 for an imaging light path to pass through is arranged on a convex surface (the LED lamp irradiates to the first surface) of a large object lens (a sixth lens 206) close to a light source, the anti-stray light diaphragm 6 is a black shading cylinder and only allows imaging light rays to pass through, the imaging light rays coming out of a pupil pass through the large objective lens group 2, pass through the anti-stray light diaphragm 6 and the aperture diaphragm 3, then reach the imaging lens group 4, and finally reach the image acquisition device 5 for imaging.

The present invention is not limited to the above embodiments, and those skilled in the art can understand that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. The utility model provides a contact eye ground camera illumination light path system, includes light source, big objective lens group, aperture diaphragm, imaging lens group and image acquisition device, the light source is the annular light source who is enclosed by many LED lamps, annular light source arranges around the imaging light path, big objective lens group comprises at least three big objective lens, its characterized in that: all the large objective lenses of the large objective lens group are sequentially glued together, the gluing surfaces of the large objective lenses are coated with films, and the positions of the LED lamps are conjugated with pupils.

2. The contact type fundus camera illumination optical path system according to claim 1, wherein: an anti-impurity diaphragm for an imaging light path to pass through is arranged on the convex surface of the large object lens close to the light source, the anti-impurity diaphragm is a black shading cylinder, and imaging light rays coming out of a pupil reach the imaging lens group after passing through the large objective lens group, the anti-impurity diaphragm and the aperture diaphragm.

3. The contact type fundus camera illumination optical path system according to claim 1 or 2, characterized in that: the big objective lens group consists of 6 big objective lenses.

4. The contact type fundus camera illumination optical path system according to claim 3, wherein: the image acquisition device is a CCD camera or an externally purchased lens component.

5. The contact type fundus camera illumination optical path system according to claim 1, wherein: the refractive indexes of the bonding materials of the bonding surfaces are arranged at intervals from high to low in sequence from the position close to the pupil to the position far away from the pupil.