CN212515293U - Optical system of fundus camera - Google Patents

Abstract

The utility model discloses an optical system of eye ground camera, including lighting system and imaging system, lighting system includes annular diaphragm, black spot board, dodge mirror, condensing lens, annular light source and half anti half mirror of passing through, imaging system includes prism group, imaging chip, omentum objective, imaging objective group, imaging chip CCD and shared objective, the rear portion of dodge mirror is provided with the LED light source, the centre of omentum objective and half anti half mirror of passing through is provided with public focal plane. The utility model has the advantages of novel structure, design benefit, facilitate the use, realized shooting the image in same eye ground retina membrane region simultaneously from different angles, improved disease diagnosis's accuracy, be fit for extensively promoting.

Description

Optical system of fundus camera

Technical Field

The utility model relates to an ophthalmology technical field particularly, relates to an optical system of eye ground camera.

Background

An eyeground camera belongs to the field of medical imaging and is used for acquiring an image of retina of a human eye so as to facilitate medical staff to check eyeground diseases or assist the medical staff to judge the state of illness of other organs. Since the blood vessels of the fundus are the only blood vessels that can be directly observed by the human body through the body surface, medical personnel can check whether the optic nerve, retina, choroid and refraction medium of the fundus have pathological changes through the fundus camera, and can also assist in diagnosing and judging the disease conditions of other system diseases through the fundus camera, for example, screening retinal pictures to detect cerebral infarction, cerebral hemorrhage, cerebral arteriosclerosis, brain tumors, diabetes, nephropathy, hypertension, retinopathy of prematurity, glaucoma, age-related macular degeneration and the like. Since the earlier detection of these diseases is more advantageous for clinical treatment, fundus cameras are widely used for clinical screening of fundus diseases, and are indispensable medical instruments. Fundus camera optical path design typically includes the following components: fundus photographic optical paths (illumination and imaging optical paths) are usually added with a vision fixation target optical path and an iris photographic optical path for obtaining stable high-quality pictures, wherein the vision fixation target optical path is fixed in a certain specific direction for the eye to be detected to watch, and the iris photographic optical path is mainly used for determining the direction of the eye to be detected so as to adjust equipment to align the eye to be detected. Some devices, in order to reduce cost, may not include a vision fixation target optical path, and may operate to fix the patient's eye in front or in a certain direction, or may not include an iris photography optical path, and may use the fundus photography optical path to locate the initial position of the eye by changing the focal length of the combined lens. The existing fundus camera has low quality of shot pictures, certain deviation of the detected precision and result, difficult operation, uncomfortable patient detection, difficult use for people, and simultaneously can not simultaneously shoot images of the same fundus retina area from different angles, the accuracy of disease diagnosis is low, and the state and the image quality of the fundus images shot at different times are different, and the registration result is inevitably unsatisfactory. An effective solution to the problems in the related art has not been proposed yet.

SUMMERY OF THE UTILITY MODEL

To the problem among the correlation technique, the utility model provides an optical system of eye ground camera to overcome the above-mentioned technical problem that current correlation technique exists.

The technical scheme of the utility model is realized like this:

the utility model provides an optical system of eye ground camera, includes lighting system and imaging system, lighting system includes annular diaphragm 1, black spot board 2, dodge mirror 3, condenser 4, annular light source 5 and half anti-half mirror 6, imaging system includes prism group 7, imaging chip, omentum objective 8, imaging objective group 9, imaging chip CCD10 and sharing objective 11, half anti-half mirror 6 sets up at the rear portion of omentum objective 8 slope 45 degrees, condenser 4 sets up the lower part at half anti-half mirror 6, annular diaphragm 1 sets up the centre at dodge mirror 3 and condenser 4, the rear portion of dodge mirror 3 is provided with the LED light source, black spot board 2 sets up the rear portion at condenser 4, the centre of omentum objective 8 and half anti-half mirror 6 is provided with public focal plane 12.

Furthermore, the optical lenses in the semi-reflecting and semi-transmitting lens 6 are all plated with anti-reflection coatings.

Further, the prism group 7 includes a first prism and a second prism, and the imaging objective group 9 includes a first imaging objective and a second imaging objective.

Further, the imaging chip CCD10 has two.

Further, the light reflected by the human eye passes through the common objective lens 11 and is separated into two symmetrical parallel sub-optical paths by the prism group 7, and the image of the retina is finally imaged on the two imaging chips CCD10 by the imaging objective lenses on the two parallel sub-optical paths, respectively.

The utility model has the advantages that: the utility model provides an optical system of eye ground camera, novel structure has, design benefit, the advantage that facilitates the use, realize shooting the image in same eye ground retina membrane region simultaneously from different angles, eliminate the stray light that omentum objective produced through setting up the black spot board, and add the annular diaphragm in order to avoid the production of cornea reverberation, the quality of picture has been improved, prism group comprises two prisms, prism group and common objective mutually support and separate into two parallel sub-light paths with the main light path, be favorable to improving ophthalmic disease diagnostic accuracy and wholeness, and is suitable for extensive popularization.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and 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 these drawings without creative efforts.

Fig. 1 is an overall configuration diagram of an optical system of an eye fundus camera according to an embodiment of the present invention;

in the figure:

1. an annular diaphragm; 2. a black spot plate; 3. a light homogenizing mirror; 4. a condenser lens; 5. an annular light source; 6. a half-reflecting and half-transmitting mirror; 7. a prism group; 8. a mesh objective lens; 9. an imaging objective lens group; 10. an imaging chip CCD; 11. a common objective lens; 12. a common focal plane.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art all belong to the protection scope of the present invention.

According to an embodiment of the utility model, an optical system of eye ground camera is provided.

As shown in fig. 1, an optical system of an eye fundus camera according to an embodiment of the present invention comprises an illumination system and an imaging system, the illumination system comprises an annular diaphragm 1, a black spot plate 2, a light homogenizing lens 3, a collecting lens 4, an annular light source 5 and a transflective lens 6, the imaging system comprises a prism group 7, an imaging chip, a web objective 8, an imaging objective group 9, an imaging chip CCD10 and a shared objective 11, the transflective lens 6 is arranged at the rear part of the web objective 8 with an inclination of 45 degrees, the collecting lens 4 is arranged at the lower part of the transflective lens 6, the annular diaphragm 1 is arranged between the light homogenizing lens 3 and the collecting lens 4, the rear part of the light homogenizing lens 3 is provided with an LED light source, the black spot plate 2 is arranged at the rear part of the collecting lens 4, the middle parts of the web objective 8 and the transflective lens 6 are provided with a common focal plane 12, optical lenses in the transflective lens 6 are coated with an antireflection coating, the prism group 7 comprises a first prism and a second prism, the imaging objective group 9 comprises a first imaging objective and a second imaging objective, the number of the imaging chips CCD10 is two, light reflected by human eyes passes through the shared objective 11 and is separated into two symmetrical parallel sub-light paths by the prism group 7, and finally, the images of the retina are imaged on the two imaging chips CCD10 by the imaging objectives on the two parallel sub-light paths respectively.

By means of the technical scheme, an optical system of eye ground camera, including lighting system and imaging system, lighting system includes annular diaphragm 1, black spot board 2, dodge mirror 3, condensing lens 4, annular light source 5 and half anti-semi-transparent mirror 6, imaging system includes prism group 7, imaging chip, omentum objective 8, imaging objective group 9, imaging chip CCD10 and sharing objective 11, half anti-semi-transparent mirror 6 sets up at the rear portion of omentum objective 8 slope 45 degrees, condensing lens 4 sets up the lower part at half anti-semi-transparent mirror 6, annular diaphragm 1 sets up in the centre of dodge mirror 3 and condensing lens 4, the rear portion of dodge mirror 3 is provided with the LED light source, black spot board 2 sets up the rear portion at condensing lens 4, the centre of omentum objective 8 and half anti-semi-transparent mirror 6 is provided with public focal plane 12, all there is anti-reflection coating on the optical lens in half anti-semi-transparent mirror 6, the prism group 7 comprises a first prism and a second prism, the imaging objective group 9 comprises a first imaging objective and a second imaging objective, the number of the imaging chips CCD10 is two, light reflected by human eyes passes through the shared objective 11 and is separated into two symmetrical parallel sub-light paths by the prism group 7, and finally, the images of the retina are imaged on the two imaging chips CCD10 by the imaging objectives on the two parallel sub-light paths respectively. In the imaging system, in order to avoid the eyelash of the patient touching the lens surface of the instrument in the examination, the working distance of the instrument should not be less than 10 mm, and the working distance of the optical system is set to be 13 mm. The retina objective lens is a lens group which is closest to human eyes in an imaging system and mainly plays a role in forming a clear real image of the retina at the back of the retina objective lens. The exposure of human eyes can not exceed the safe range, otherwise, the human eyes can be burnt. When an imaging objective lens is designed, the system is considered to image on two CCDs simultaneously and respectively, the light energy received by each CCD is less than half of the total light energy, under the condition that the total exposure is certain, the illumination brightness of the system is much weaker than that of a monocular fundus camera, the imaging quality is influenced inevitably, and therefore a strong light objective lens capable of well imaging weak light is required to be used. The prism group consists of two prisms, the prism group and the shared objective are matched with each other to separate the main light path into two parallel sub-light paths, and the imaging objective and the CCD are placed on the two parallel sub-light paths to complete the final imaging task. In the illumination system, a coaxial illumination mode is adopted to ensure the illumination uniformity, namely the illumination system and the imaging system share the omentum objective lens through a half-reflecting and half-transmitting lens. The central region of the cornea of the eye has a high reflectivity for light incident on the eye, and if this reflected light is mixed into the imaging system, the imaging quality is significantly reduced. The interference of the reflected light of the cornea to an imaging system is weakened by adopting an annular illumination mode, namely, the light is incident into human eyes from the edge of the cornea, so that a central area with higher reflectivity on the surface of the cornea can be avoided. The imaging system and the illumination system share a net film objective lens, a small amount of reflected light can be generated on each surface of the net film objective lens and mixed into the imaging system to form a ghost image, the ghost image can reduce the imaging quality, and the reflected light forming the ghost image can be eliminated by adopting a method of adding a black spot plate.

The utility model has the advantages of novel structure, design benefit, facilitate the use, realize shooting the image in same ground retina membrane region simultaneously from different angles, eliminate the stray light that omentum objective produced through setting up the black spot board, and add the production of annular diaphragm in order to avoid the cornea reverberation, the quality of photo has been improved, prism group comprises two prisms, prism group mutually supports with common objective and separates into two parallel sub-light paths with the main light path, be favorable to improving the diagnostic accuracy of ophthalmic diseases and wholeness, and is suitable for extensive popularization.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "disposed," "connected," "fixed," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through an intermediate medium, and may be connected through the inside of two elements or in an interaction relationship between two elements, unless otherwise specifically defined, and the specific meaning of the above terms in the present invention will be understood by those skilled in the art according to specific situations.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. The utility model provides an optical system of eye ground camera, includes lighting system and imaging system, its characterized in that, lighting system includes annular diaphragm (1), black spot board (2), dodge mirror (3), condensing lens (4), annular light source (5) and half reflection half mirror (6), imaging system includes prism group (7), imaging chip, omentum objective (8), imaging objective group (9), imaging chip CCD (10) and sharing objective (11), half reflection half mirror (6) set up at the rear portion of omentum objective (8) slope 45 degrees, condensing lens (4) set up the lower part at half reflection half mirror (6), annular diaphragm (1) sets up in the centre of dodge mirror (3) and condensing lens (4), the rear portion of dodge mirror (3) is provided with the LED light source, black spot board (2) set up the rear portion at condensing lens (4), and a common focal plane (12) is arranged between the omentum objective lens (8) and the semi-reflecting and semi-transmitting lens (6).

2. An optical system of a fundus camera according to claim 1, characterized in that the optical lenses in the half-reflecting and half-transmitting mirror (6) are coated with an anti-reflection coating.

3. An optical system of a fundus camera according to claim 1, characterized in that said prism set (7) comprises a first prism and a second prism and said imaging objective set (9) comprises a first imaging objective and a second imaging objective.

4. An optical system of a fundus camera according to claim 1 characterized in that said imaging chips CCD (10) are two.

5. An optical system of an eyeground camera as claimed in claim 1, characterized in that, the reflected light of the human eye is split into two symmetrical parallel sub-optical paths by the prism group (7) after passing through the common objective lens (11), and the images of the retina are finally imaged on two imaging chips CCD (10) by the imaging objective lenses on the two parallel sub-optical paths respectively.

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