Fundus camera lighting system and fundus camera

Abstract

The present invention provides a fundus camera illumination system and fundus camera. The fundus camera illumination system includes at least one light source disposed within a lens barrel, located on one side of the lens barrel's central axis; and a reflective structure disposed within the lens barrel, opposite the light source, for reflecting light emitted by the light source so that it passes through an eyepiece assembly or an objective lens disposed within the lens barrel, thereby forming an image outside the lens barrel. Compared to existing internal illumination methods, the fundus camera illumination system of the present invention eliminates the need for separate components disposed outside the lens barrel, resulting in a smaller and easier-to-assemble fundus camera.

Description

Technical Field

[0001] The present invention relates to the technical field of fundus cameras, and in particular to a fundus camera lighting system and a fundus camera. Background Art

[0002] The eye is the human visual organ for perceiving the world. External objects are reflected through the eye's optical system as an inverted, real image on the retina. The optical signal is then converted into optic nerve signals and transmitted to the brain. As the only tissue in the body capable of non-invasively observing blood vessels and their distribution in vivo, the retina has become a crucial window for diagnosing eye diseases and related systemic disorders. This not only allows for the diagnosis of the most common eye conditions, but also allows for the early diagnosis of conditions such as hypertension, diabetes, and thrombosis (systemic diseases, especially those related to blood flow, often manifest in the fundus).

[0003] The most important instrument for fundus optical imaging is the fundus camera. Currently, the mainstream structure of a fundus camera consists of four components: an imaging system, an illumination system, a positioning optical path, and a focusing optical path. The requirements for the imaging and illumination systems are to optimize the spatial arrangement of the illumination and imaging optical paths, while selecting an appropriate imaging light source, to eliminate stray light and ghost images generated by the corneal and retinal objective lenses. Currently, there are two main principles for fundus cameras (Li Can and Sun Qiang, Design and Development of a Novel Fundus Camera [PhD Dissertation, University of Chinese Academy of Sciences], April 2014): external illumination and internal illumination. The structures of these two illumination methods are essentially the same, retaining the main structure of traditional fundus cameras, consisting of an illumination optical system and an imaging optical system. The main difference between the two structures is that external illumination cameras use a semi-reflective plane mirror as the beam splitter for the illumination and imaging optical paths, and the two systems do not share a common lens group. In contrast, internal illumination cameras use a hollow reflector as the beam splitter for the two optical paths, and both optical systems share a common retinal objective lens. In comparison, the internal lighting method has uniform fundus lighting energy and high energy utilization rate. The black dot plate also avoids the ghost images produced by the retina objective lens. It has the advantages of low production cost, reasonable structure and clear imaging.

[0004] However, internally illuminated fundus cameras require separate components such as a light collecting lens, an annular aperture, a condenser lens, and a black dot plate to be installed outside the lens barrel, resulting in a large size and complex assembly of the fundus camera. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the technical defects of the existing fundus camera with internal lighting, which requires the separate arrangement of components such as a light collecting mirror outside the lens barrel, resulting in the fundus camera being large in size and complicated to assemble. The present invention thus provides a fundus camera lighting system that does not require the separate arrangement of components outside the lens barrel, and thus the fundus camera is small in size and simple to assemble.

[0006] The present invention also provides a fundus camera having the fundus camera lighting system.

[0007] To this end, the present invention provides a fundus camera lighting system, comprising:

[0008] At least one light source is disposed inside the lens barrel and located on one side of the central axis of the lens barrel;

[0009] The reflective structure is arranged inside the lens barrel, opposite to the light source, and is used to reflect the light emitted by the light source so that the light source forms an image outside the lens barrel after passing through the eyepiece group or eyepiece objective lens arranged inside the lens barrel.

[0010] As a preferred solution, the light source is a plurality of point light sources arranged in a circular structure.

[0011] As a preferred solution, an annular light plate is fixedly provided inside the lens barrel, and the light source is fixedly provided on one side surface of the annular light plate.

[0012] As a preferred solution, the reflective structure includes:

[0013] a first reflecting surface arranged in a ring shape, receiving and reflecting light from the light source;

[0014] a second reflecting surface, located inside the first reflecting surface and arranged in a ring shape, receiving the reflected light from the first reflecting surface and further reflecting it outwards;

[0015] a connecting surface, connecting the first reflecting surface and the second reflecting surface;

[0016] A central through hole is formed in the central portion of the second reflecting surfaces arranged in a ring shape.

[0017] As a preferred solution, the first reflecting surface and / or the second reflecting surface is a total reflecting surface.

[0018] As a preferred solution, the first reflecting surface is in the shape of a spherical reflecting surface, an aspherical reflecting surface, or a free-form surface.

[0019] As a preferred solution, the second reflecting surface is a planar reflecting surface.

[0020] As a preferred solution, the light source includes an infrared light source and / or a visible light source.

[0021] As a preferred solution, a collimating lens is further included and arranged between the light source and the reflective structure.

[0022] The present invention also provides a fundus camera, comprising: a lens barrel, and an eyepiece lens group or an eyepiece objective lens, an illumination system, and an objective lens group sequentially arranged inside the lens barrel, wherein the illumination system is any of the fundus camera illumination systems described above.

[0023] The technical solution provided by the present invention has the following advantages:

[0024] 1. The fundus camera illumination system of the present invention includes a light source and a reflective structure, both of which are disposed within a lens barrel. The reflective structure reflects light emitted by the light source, which then forms an image outside the lens barrel after passing through an eyepiece assembly or an objective lens disposed within the lens barrel. When used for fundus photography, the light source forms an image at the corneal limbus, located outside the lens barrel. Light enters the eye from this limbus, illuminating the fundus. Compared to prior art internal illumination methods, the fundus camera illumination system of the present invention eliminates the need for separate components external to the lens barrel, resulting in a smaller fundus camera and easier assembly.

[0025] 2. The fundus camera illumination system of the present invention comprises multiple point light sources arranged in a circular configuration. These point light sources are reflected by a reflective structure and, after passing through the eyepiece assembly or objective lens, form images of the multiple point light sources at the corneal margin of the subject's eye. The light then enters the eye from the corneal margin, illuminating the fundus for a more effective illumination effect.

[0026] 3. The light source of the fundus camera illumination system of the present invention is arranged inside the lens barrel via an annular light plate, which is easy to disassemble and assemble, and convenient for maintenance. The annular light plate is hollow in the middle, which not only allows the reflected light of the reflective structure to be emitted, but also does not affect the imaging optical path.

[0027] 4. The fundus camera illumination system of the present invention comprises a reflective structure comprising a first reflective surface arranged in an annular manner, a second reflective surface arranged in an annular manner, and a connecting surface connecting the first and second reflective surfaces. The annular second reflective surface encloses a central through-hole for passage of imaging light. The first reflective surface receives and reflects light from a light source, and the second reflective surface receives and further reflects the light reflected from the first reflective surface outward. The light further reflected outward, after passing through an eyepiece assembly or an eyepiece objective lens, forms an image on the cornea of ​​the subject to be observed, thereby illuminating the fundus.

[0028] 5. In the fundus camera illumination system of the present invention, the first and / or second reflective surfaces are fully reflective surfaces, which improve light utilization and prevent stray light from entering the imaging optical path. This allows for the omission of reflective film layers in the illumination optical path, reducing costs. The first reflective surface can be a spherical, aspherical, or free-form surface, primarily designed to reflect all light from the light source onto the second reflective surface. The second reflective surface is a planar reflective surface, which can direct light from the first reflective surface to a specific angle range as much as possible, thereby improving light utilization, assisting the light source in achieving imaging, and preventing stray light from entering the imaging optical path.

[0029] 6. The fundus camera lighting system of the present invention comprises an infrared light source and / or a visible light source; the infrared light source is used for aligning and focusing the fundus, and the visible light source is used for capturing fundus images, eliminating the pupil dilation step.

[0030] 7. The fundus camera illumination system of the present invention further includes a collimating lens, which is arranged between the light source and the reflective structure, and is used to collimate the light and increase the amount of light directed to the first reflective surface.

[0031] 8. The present invention further provides a fundus camera comprising a lens barrel, an eyepiece assembly or an eyepiece objective lens disposed within the lens barrel, an objective lens assembly, and an illumination system, wherein the illumination system is the fundus camera illumination system described above; since the fundus camera illumination system described above is adopted, the camera naturally has all the advantages brought about by the adoption of the aforementioned illumination system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the prior art or the specific embodiments of the present invention, the following briefly introduces the drawings used in the description of the prior art or the specific embodiments.

[0033] Figure 1 It is a structural principle diagram of the fundus camera lighting system of the present invention.

[0034] Figure 2 It is a schematic diagram of the light path of light reflected by the reflective structure.

[0035] Figure 3 It is a three-dimensional image of a reflective structure.

[0036] Figure 4 It is another three-dimensional image of the reflective structure.

[0037] Figure 5 is a side view of the reflective structure.

[0038] Figure 6 This is the main view of the ring light panel.

[0039] Figure numerals: 10, lens barrel; 1, light source; 11, infrared light source; 12, visible light source; 2, reflective structure; 21, first reflective surface; 22, second reflective surface; 23, connecting surface; 24, middle through hole; 25, incident surface; 3, annular light panel; 4, collimating lens; 5, eyepiece group; 6, objective lens group. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is described in detail below.

[0041] Example 1

[0042] This embodiment provides a fundus camera lighting system, such as Figure 1 As shown, it includes: at least one light source 1, which is arranged inside the lens barrel 10 and is located on one side of the central axis of the lens barrel 10; a reflective structure 2, which is arranged inside the lens barrel 10 and opposite to the light source 1, and is used to reflect the light emitted by the light source 1, so that the light source 1 forms an image outside the lens barrel 10 after passing through the eyepiece group 5 or the eyepiece objective lens arranged inside the lens barrel 10.

[0043] The fundus camera illumination system of this embodiment includes a light source 1 and a reflective structure 2, both of which are disposed within a lens barrel 10. The reflective structure 2 reflects light emitted by the light source 1, which then passes through an eyepiece assembly 5 or an objective lens disposed within the lens barrel 10, forming an image outside the lens barrel 10. When used for fundus photography, the light source 1 forms an image at the corneal margin located outside the lens barrel 10, from which light enters the eye and illuminates the fundus. Compared to existing internal illumination methods, the fundus camera illumination system of this embodiment eliminates the need for separate components disposed outside the lens barrel 10, resulting in a smaller and easier-to-assemble fundus camera.

[0044] like Figure 6 As shown, the light source 1 comprises multiple point light sources arranged in a circular configuration. The multiple point light sources are reflected by the reflective structure 2 and, after passing through the eyepiece assembly 5 or the objective lens, form images of the multiple point light sources at the corneal margin of the observer's eye. The light enters the eye from the corneal margin, illuminating the fundus, achieving a better illumination effect.

[0045] An annular light panel 3 is fixedly mounted within the lens barrel 10, with the light source 1 fixedly mounted on one side of the annular light panel 3. Light source 1 is mounted within the lens barrel 10 via the annular light panel 3, making assembly and disassembly easy and convenient for maintenance. The hollow center of the annular light panel 3 not only allows light reflected from the reflective structure 2 to be emitted, but also does not affect the imaging optical path.

[0046] The light source 1 includes an infrared light source 11 and / or a visible light source 12. The infrared light source 11 is used for aligning and focusing the fundus, and the visible light source 12 is used for capturing fundus images, eliminating the need for pupil dilation.

[0047] like Figure 2-4 As shown, the reflective structure 2 includes: a first reflective surface 21, arranged in a ring shape, receiving and reflecting light from the light source 1; a second reflective surface 22, located inside the first reflective surface 21, arranged in a ring shape, receiving the reflected light from the first reflective surface 21 and further reflecting it outward; a connecting surface 23, connecting the first reflective surface 21 and the second reflective surface 22; and a central through hole 24, formed in the middle of the second reflective surface 22 arranged in a ring shape.

[0048] The annularly arranged second reflective surfaces 22 enclose a central through hole 24 for allowing imaging light to pass through; the first reflective surface 21 receives and reflects light from the light source 1, and the second reflective surface 22 receives the reflected light from the first reflective surface 21 and further reflects it outward; the light further reflected outward passes through the eyepiece group 5 or the eyepiece objective lens and forms an image on the cornea of ​​the observer to illuminate the fundus.

[0049] In this embodiment, the first reflective surface 21 and / or the second reflective surface 22 are total reflective surfaces. The material of the reflective structure 2 is optical plastic or optical glass, and the spherical total reflective surface and the conical total reflective surface meet the total reflection condition. Taking the reflective structure 2 as an example of PMMA (refractive index 1.49), to achieve the total reflection condition, the angle θ between the tangent line at any point of the spherical total reflective surface and the incident surface of the reflective bowl must be ≥40° (e.g. Figure 5 shown).

[0050] The first reflective surface 21 is a spherical reflective surface; as a variation, the first reflective surface 21 can also be an aspherical reflective surface or a free-form surface. This improves light utilization and prevents stray light from entering the imaging optical path, omitting the reflective film layer in the illumination optical path and reducing costs. The second reflective surface 22 is a planar reflective surface. It can direct light from the first reflective surface 21 to a specific angle range as much as possible, improving light utilization, helping the light source achieve imaging, and preventing stray light from entering the imaging optical path.

[0051] like Figure 2 As shown, a collimating lens 4 is further included, which is disposed between the light source 1 and the reflective structure 2 to collimate the light and increase the amount of light directed toward the first reflective surface 21 .

[0052] The operating principle of the fundus camera illumination system in this embodiment is as follows: the light source 1 is activated, and the emitted light is collimated by the collimating lens 4 and enters the reflective structure 2 through the incident surface 25. The light is first reflected by the first reflective surface 21 to the second reflective surface 22, and then reflected through the central through-hole of the annular light plate 3. After being converged by the eyepiece group 5, it is imaged outside the lens barrel 10. If the human eye is outside the lens barrel 10, the distance can be adjusted so that the light source 1 is imaged on the corneal edge of the human eye to illuminate the fundus.

[0053] Example 2

[0054] This embodiment provides a fundus camera, comprising: a lens barrel 10, and an eyepiece lens group 5 or an eyepiece objective lens, an illumination system, and an objective lens group 6 sequentially arranged inside the lens barrel 10. The illumination system is the fundus camera illumination system described in Example 1.

[0055] Since the fundus camera of this embodiment adopts the above-mentioned fundus camera lighting system, it naturally has all the advantages brought by adopting the above-mentioned lighting system.

[0056] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A fundus camera lighting system, characterized in that: include: At least one light source (1) is disposed inside the lens barrel (10) and is located on one side of the central axis of the lens barrel (10); A reflective structure (2) is arranged inside the lens barrel (10) and opposite to the light source (1), and is used to reflect light emitted by the light source (1) so that the light source (1) forms an image outside the lens barrel (10) after passing through an eyepiece group (5) or an eyepiece objective lens arranged inside the lens barrel (10); The reflective structure (2) comprises: A first reflecting surface (21) is arranged in a ring shape and receives and reflects light from the light source; a second reflecting surface (22), located inside the first reflecting surface (21), arranged in a ring shape, receiving the reflected light from the first reflecting surface (21) and further reflecting it outward; a connecting surface (23) connecting the first reflecting surface (21) and the second reflecting surface (22); a central through hole (24) formed in the middle of the second reflecting surface (22) arranged in an annular shape; and It also includes a collimating lens (4) arranged between the light source (1) and the reflective structure (2).

2. The fundus camera lighting system according to claim 1, wherein: The light source (1) is a plurality of point light sources arranged in a circular structure.

3. The fundus camera illumination system according to claim 2, wherein: An annular light plate (3) is fixedly arranged inside the lens barrel (10), and the light source (1) is fixedly arranged on one side surface of the annular light plate (3).

4. The fundus camera lighting system according to claim 1, wherein: The first reflecting surface (21) and / or the second reflecting surface (22) are total reflecting surfaces.

5. The fundus camera lighting system according to claim 1, wherein: The first reflecting surface (21) is a spherical reflecting surface, or an aspherical reflecting surface, or a free-form surface.

6. The fundus camera lighting system according to claim 1, wherein: The second reflecting surface (22) is a planar reflecting surface.

7. The fundus camera lighting system according to any one of claims 1 to 3, characterized in that: The light source (1) includes an infrared light source (11) and / or a visible light source (12).

8. A fundus camera comprising: A lens barrel (10), and an eyepiece lens group (5) or an eyepiece objective lens, an illumination system, and an objective lens group (6) sequentially arranged inside the lens barrel (10), characterized in that the illumination system is the fundus camera illumination system according to any one of claims 1 to 7.

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