Focusing-free ellipsoidal fundus imaging system

Abstract

The invention discloses a focusing-free ellipsoidal fundus imaging system, and belongs to the technical field of fundus imaging. The system comprises a light source module, a light splitting module, a light condensing module, a scanning module, a light detection module, a focusing-free transmitting mirror group and an ellipsoidal reflector, light rays sequentially pass through the light splitting module, the light condensing module, the scanning module, the focusing-free transmitting mirror group and the ellipsoidal reflector and reach human eyes through pupils; reflected light of human eyes sequentially passes through the ellipsoidal reflector, the focusing-free transmitting mirror group, the scanning module, the light condensing module and the light splitting module to the light detection module, and the light detection module converts a light signal into a digital image. A human eye pupil is located at a first focus of the ellipsoidal reflector, and an entrance pupil of the focusing-free transmitting mirror group is located at a second focus; the ellipsoidal reflector transmits incident light to human eyes and transmits reflected light back to the focusing-free transmitting mirror group; and the focusing-free lens group is used for correcting field aberration and compensating human eye diopter aberration. The system has the advantages of ultra-wide angle, high resolution, no mydriasis and simple operation.

Description

Technical Field

[0001] The invention belongs to the technical field of fundus imaging, and more specifically, relates to a focus-free ellipsoidal fundus imaging system. Background Art

[0002] The eye is the most important organ for humans to obtain information from the outside world. More than 80% of the information humans obtain is obtained through vision. Fundus diseases such as central serous chorioretinopathy, age-related maculopathy, and retinal vein occlusion can affect the normal physiological structure and function of the eye. The early symptoms of most fundus diseases are not obvious, making them difficult to detect and control in time. By the time obvious symptoms appear, the patient's vision has often been irreversibly damaged. Therefore, early examination is very important for the prevention and treatment of fundus diseases.

[0003] Fundus imaging equipment is an important ophthalmic device used to image the retina. It is an important means for doctors to perform retinal examinations and has been widely used in the clinical diagnosis of fundus diseases. When performing fundus testing on the human eye, the refractive power of the human eye will have a certain impact on the clarity of the fundus imaging, resulting in reduced imaging resolution, blurred images, and easy misdiagnosis. Refractive compensation is usually performed by manually or electrically moving the focusing lens, which easily increases the complexity of the equipment and the difficulty of operation. If free-form surface lenses are used to achieve focus-free fundus imaging, although a larger range of refractive power imaging of the human eye can be achieved, the manufacture of free-form surface lenses is relatively complex and costly, making it difficult to mass produce. Summary of the invention

[0004] In view of the defects of the related art, the purpose of the present invention is to provide a focus-free ellipsoidal fundus imaging system, aiming to solve the problems that the existing fundus imaging equipment uses a movable lens for refractive compensation, which has cumbersome operation, the use of a free-form surface lens has a high manufacturing cost, and the field of view is small, which easily leads to missed diagnosis of peripheral retinal lesions.

[0005] To achieve the above-mentioned object, the present invention provides a focus-free ellipsoidal fundus imaging system, comprising: a light source module, a light splitting module, a light focusing module, a scanning module, a light detection module, a focus-free transmission lens group and an ellipsoidal reflector;

[0006] The light source module is used to emit light; the light passes through the splitter module, the focusing module, the scanning module, the focus-free transmission mirror group and the ellipsoidal reflector in sequence along the first light path direction, and then reaches the retina of the human eye through the pupil; the reflected light from the fundus of the human eye passes through the ellipsoidal reflector, the focus-free transmission mirror group, the scanning module, the focusing module and the splitter module in sequence along the second light path direction, and is split in the splitter module and incident on the light detection module, and the light detection module converts the light signal into a digital image; wherein the scanning module is used to emit light with different field angles in the same direction;

[0007] The ellipsoidal reflector has a first focus and a second focus, the pupil of the human eye is located at the first focus, and the entrance pupil of the focus-free transmission mirror group is located at the second focus, and the two form a conjugate relationship; the ellipsoidal reflector is used to transmit the incident light to the human eye, and transmit the reflected light of the human eye back to the focus-free transmission mirror group;

[0008] The focus-free lens group is used to correct the field aberration and compensate for the diopter aberration of the human eye; the focus-free transmission lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence along the first optical path direction; the eighth lens, the ninth lens and the tenth lens are used to correct the aberration of the reflected light within the 200° field angle of the human eye retina, and converge the field light reflected by the ellipsoidal reflector to form a primary image plane between the sixth lens and the seventh lens; the sixth lens and the seventh lens are used to correct the aberration of the primary imaging plane; the fifth lens and the fourth lens are used to compress the light size to match it with the scanning module and correct the aberration at the same time; the first lens, the second lens and the third lens are used to perform aberration correction on the exit pupil, and adjust the angle between the light and the optical axis of the focus-free transmission lens group so that the light is parallel to the optical axis of the focus-free transmission lens group;

[0009] The scanning module is used to emit light with different field angles in the same direction;

[0010] The focusing module is used to convert the incident light in the first light path into parallel light, and to converge the light passing through the scanning module to the light splitting module in the second light path.

[0011] Optionally, the scanning module uses a two-dimensional galvanometer, and the vibration amplitude of the two-dimensional galvanometer is not greater than 20°.

[0012] Optionally, the center of the scanning module and the focus-free transmission mirror group are on the same optical axis; the reflected light of the focus-free transmission mirror group along the second optical path is reflected by the two-dimensional galvanometer so that light rays from different fields of view are emitted in the same direction.

[0013] Optionally, the first lens is a cemented lens, the first surface along the first optical path direction is a convex surface, the radius of curvature is set to -110 to -120 mm, the second surface is a concave surface relative to the first surface, the radius of curvature is set to 15 to 20 mm, the third surface is a concave surface, the radius of curvature is set to 30 to 40 mm, the center thickness between the first surface and the second surface is 3 to 4 mm, and the center thickness between the second surface and the third surface is 6 to 7 mm;

[0014] The first surface of the second lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -100 to -110 mm, and the center thickness is 9 to 10 mm;

[0015] The first surface of the third lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -4000 to -4100 mm, and the center thickness is 9 to 10 mm;

[0016] The first surface of the fourth lens along the first optical path is a concave surface, the radius of curvature is set to 330-340 mm, the second surface is a convex surface, the radius of curvature is set to -60--70 mm, and the center thickness is 10-15 mm;

[0017] The first surface of the fifth lens along the first optical path is a convex surface, the radius of curvature is set to -40 to -50 mm, the second surface is a convex surface, the radius of curvature is set to -20 to -30 mm, and the center thickness is 14 to 15 mm;

[0018] The first surface of the sixth lens along the first optical path is a convex surface, the radius of curvature is set to -60 to -70 mm, the second surface is a concave surface, the radius of curvature is set to 430 to 440 mm, and the center thickness is 25 to 30 mm;

[0019] The first surface of the seventh lens along the first optical path is a concave surface, the radius of curvature is set to 220-230 mm, the second surface is a concave surface, the radius of curvature is set to 70-80 mm, and the center thickness is 25-30 mm;

[0020] The first surface of the eighth lens along the first optical path is a convex surface, the radius of curvature is set to -35 to -40 mm, the second surface is a concave surface, the radius of curvature is set to 50 to 60 mm, and the center thickness is 15 to 20 mm;

[0021] The first surface of the ninth lens along the first optical path direction is a convex surface, the radius of curvature is set to -10 to -15 mm, the second surface is a convex surface, the radius of curvature is set to -230 to -240 mm, and the center thickness is 6 to 7 mm;

[0022] The first surface of the tenth lens along the first optical path direction is a plane, the second surface is a plane, and the center thickness is 13-14 mm.

[0023] Optionally, the gap between the second lens and the first lens is 20-25 mm;

[0024] The gap between the second lens and the third lens is 20-25 mm;

[0025] The gap between the third lens and the fourth lens is 30-35 mm; the gap between the fourth lens and the fifth lens is 35-40 mm;

[0026] The gap between the fifth lens and the sixth lens is 30-35 mm;

[0027] The gap between the sixth lens and the seventh lens is 10 to 15 mm;

[0028] The gap between the seventh lens and the eighth lens is 30-35 mm;

[0029] The gap between the eighth lens and the ninth lens is 1 to 5 mm;

[0030] The gap between the ninth lens and the tenth lens is 1 to 5 mm.

[0031] Optionally, the light source module is a single-wavelength light source or a multi-wavelength light source.

[0032] Optionally, the light source module emits laser light with a wavelength of 488nm, 520nm, 635nm, or 785nm.

[0033] Optionally, the beam splitter module is a beam splitter or a beam splitter group; the beam splitter is a cube beam splitter or a flat beam splitter.

[0034] Optionally, the light detection module includes a detector and a host computer;

[0035] The detector is used to convert the received human eye fundus reflected light into an electrical signal and transmit it to a host computer to obtain a fundus image.

[0036] Compared with the prior art, the above technical solution conceived by the present invention can achieve the following beneficial effects:

[0037] 1. The present invention provides a focus-free ellipsoid fundus imaging system. Without introducing a free-form surface, the system increases the degree of freedom by increasing the number of lenses behind the primary image plane, so that the focus-free lens group can simultaneously correct the field aberration and compensate for the diopter aberration of the human eye without the need for field splicing, and realizes ultra-wide-angle multi-wavelength confocal laser scanning fundus imaging with a single extraocular field angle of 135° (intraocular field angle of 200°). The focus-free lens group can realize focus-free imaging of -15D to +15D human eyes without moving the lens group, and the full-field optical resolution reaches 23um. The focus-free lens group can realize the correction of field aberration and compensation of diopter aberration of the human eye by using a plurality of ordinary lenses, and the manufacturing cost is lower than that of the free-form surface lens. The whole system has the advantages of ultra-wide angle, high resolution, simple operation and easy manufacturing.

[0038] 2. The present invention provides a focus-free ellipsoid fundus imaging system. The system light source module can selectively emit multi-wavelength lasers with wavelengths of 488nm, 520nm, 635nm, and 785nm, which can obtain retinal color photos and obtain richer retinal information. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of a focus-free ellipsoid fundus imaging system provided by an embodiment of the present invention;

[0040] Figure 2 is a structural schematic diagram of a focus-free transmission lens assembly provided by an embodiment of the present invention;

[0041] Figure 3 This is a full-field spot diagram of a human eye with a diopter of -15D according to an embodiment of the present invention;

[0042] Figure 4 This is a full-field spot diagram of a human eye with a diopter of -10D according to an embodiment of the present invention;

[0043] Figure 5 is a full-field spot diagram of a normal human eye according to an embodiment of the present invention;

[0044] Figure 6 is a full-field spot diagram of a 10D diopter human eye according to an embodiment of the present invention;

[0045] Figure 7 1 is a full field of view point diagram of a 15D diopter human eye according to an embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 1. Light source module; 2. Beam splitting module; 3. Focusing module; 4. Scanning module; 5. Focus-free transmission mirror group; 6. Ellipsoidal reflector; 7. Human eye; 8. Detector; 9. Host computer; 701, first focus; 501, second focus; A. Optical axis of the focus-free transmission mirror group. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] The contents involved in the above embodiment are described below in conjunction with a preferred embodiment.

[0050] like Figure 1 As shown, a focus-free ellipsoidal fundus imaging system comprises: a light source module 1, a light splitting module 2, a light focusing module 3, a scanning module 4, a focus-free transmission mirror group 5, an ellipsoidal reflector 6 and a light detection module;

[0051] The light source module 1 is used to emit light; the light passes through the light splitting module 2, the light focusing module 3, the scanning module 4, the focus-free transmission mirror group 5 and the ellipsoidal reflector 6 in the first light path direction, and then reaches the retina of the human eye 7 through the pupil; the fundus reflected light of the human eye 7 passes through the ellipsoidal reflector 6, the focus-free transmission mirror group 5, the scanning module 4, the light focusing module 3 and the light splitting module 2 in the second light path direction, and is split by the light splitting module 2 and incident on the light detection module, and the light detection module converts the light signal into a digital image;

[0052] The ellipsoidal reflector 6 has a first focus 701 and a second focus 501, the pupil of the human eye is located at the first focus 701, and the entrance pupil of the focus-free transmission lens group 5 is located at the second focus 501, and the two form a conjugate relationship; the ellipsoidal reflector 6 is used to transmit the incident light to the human eye 7, and transmit the reflected light of the human eye 7 back to the focus-free transmission lens group 5;

[0053] The focus-free lens group 5 is used to correct the field aberration and compensate for the diopter aberration of the human eye; the focus-free transmission lens group 5 includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence along the first optical path direction; the eighth lens, the ninth lens and the tenth lens are used to correct the aberration of the reflected light within the 200° field angle of the human eye retina, and converge the field light reflected by the ellipsoidal reflector 6 to form a primary image plane between the sixth lens and the seventh lens; the sixth lens and the seventh lens are used to correct the aberration of the primary imaging surface; the fifth lens and the fourth lens are used to compress the light size to match it with the scanning module 4, and correct the aberration at the same time; the first lens, the second lens and the third lens are used to perform aberration correction on the exit pupil, and adjust the angle between the light and the optical axis A of the focus-free transmission lens group, so that the light is parallel to the optical axis A of the focus-free transmission lens group;

[0054] The scanning module 4 is used to emit light with different viewing angles in the same direction;

[0055] The focusing module 3 is used to convert the incident light in the first light path into parallel light, and to converge the light passing through the scanning module to the light splitting module in the second light path.

[0056] The refractive power of the human eye will affect the imaging quality of fundus imaging equipment. Using a mobile focusing lens to compensate for refractive power will easily increase the complexity of the equipment and the difficulty of operation. Using a free-form surface lens to compensate for refractive power has problems such as high manufacturing cost, great manufacturing difficulty, and difficulty in mass production.

[0057] The invention provides a focus-free ellipsoidal fundus imaging system, which is composed of an ellipsoidal reflector and a focus-free transmission mirror group.

[0058] When performing fundus imaging examination, the subject places his eyes at the inspection hole of the fundus imaging system. The light source module 1 emits light, which passes through the spectroscopic module 2, and then through the focusing module 3 to the scanning module 4, and then enters the focus-free transmission mirror group 5 and the ellipsoidal reflector 6 in sequence, and then reaches the retina of the subject's human eye 7 through the pupil; the spectroscopic module 2 is used to receive the light from the light source module 1, and control the light to pass through the spectroscopic module 2 through the focusing module 3 to the scanning module 4 in a certain proportion; the spectroscopic module 2 is a spectroscope or a spectroscope group. In this embodiment, the spectroscopic module 2 is a spectroscope, which can be selected according to actual needs. The spectroscope can be a cubic spectroscope or a flat spectroscope.

[0059] The laser is reflected at the fundus of the human eye, and the reflected light passes through the ellipsoidal reflector 6, the focus-free transmission lens group 5, the scanning module 4, the focusing module 3 and the spectroscopic module 2 in sequence along the second optical path. The spectroscopic module 2 adopts a spectroscope, and is reflected to the light detection module through the spectroscope. The light detection module converts the light signal into a digital image. The scanning module 4 reflects the reflected light along the second optical path, and the light rays of different field angles will be emitted in the same direction, thereby realizing point scanning. Furthermore, the scanning module 4 adopts a two-dimensional galvanometer, and the vibration amplitude of the two-dimensional galvanometer is not greater than 20°. The center of the scanning module 4 is on the same optical axis as the focus-free transmission lens group 5; the reflected light of the focus-free transmission lens group 5 along the second optical path is reflected by the two-dimensional galvanometer so that the light rays of different fields of view are emitted in the same direction. The focusing module 3 realizes light convergence to improve the transmission effect of light, and only plays the role of converging light, and does not perform additional correction on aberrations. In a specific embodiment, the focusing module 3 includes a plano-convex lens, a biconcave lens, and a biconvex lens in sequence along the first optical path.

[0060] The core of this solution is the focus-free transmission lens group. By using the designed focus-free transmission lens group, without introducing a free-form surface, there is no need to move and adjust the position of the transmission lens to compensate for the aberration caused by the refractive human eye, and achieve focus-free imaging of -15D to +15D human eyes. The entire system has the advantages of ultra-wide angle, high resolution, simple operation and easy manufacturing. A single imaging of the extraocular field of view angle of 135° (intraocular field of view angle of 200°) is achieved, and the full-field optical resolution reaches 23um within the refractive range of -15D to +15D.

[0061] Optionally, the light source module 1 is one of a single-wavelength light source and a multi-wavelength light source; the light source module emits lasers with wavelengths of 488nm, 520nm, 635nm, and 785nm.

[0062] The light source module 1 is used to emit laser. The light source module 1 can select laser but is not limited to laser. Figure 1 The light source module 1 in the figure only shows one light source, but the actual light source module 1 can be one of a single-wavelength light source and a multi-wavelength light source; when a multi-wavelength light source is used, lasers of different wavelengths are usually combined by a beam combiner to form a beam of light and enter the spectroscopic module 2.

[0063] In this embodiment, the light source module 1 is a multi-wavelength light source with emission wavelengths of 488 nm, 520 nm, 635 nm, and 785 nm. The light is combined into a beam by a beam combiner and then enters the light splitting module 2 .

[0064] By adopting the above technical solution, the light source module 1 can be selected according to the needs to meet the multi-wavelength light source detection needs.

[0065] Optionally, the first lens is a cemented lens, the first surface along the first optical path direction is a convex surface, the radius of curvature is set to -110 to -120 mm, the second surface is a concave surface relative to the first surface, the radius of curvature is set to 15 to 20 mm, the third surface is a concave surface, the radius of curvature is set to 30 to 40 mm, the center thickness between the first surface and the second surface is 3 to 4 mm, and the center thickness between the second surface and the third surface is 6 to 7 mm;

[0066] The first surface of the second lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -100 to -110 mm, and the center thickness is 9 to 10 mm;

[0067] The first surface of the third lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -4000 to -4100 mm, and the center thickness is 9 to 10 mm;

[0068] The first surface of the fourth lens along the first optical path is a concave surface, the radius of curvature is set to 330-340 mm, the second surface is a convex surface, the radius of curvature is set to -60--70 mm, and the center thickness is 10-15 mm;

[0069] The first surface of the fifth lens along the first optical path is a convex surface, the radius of curvature is set to -40 to -50 mm, the second surface is a convex surface, the radius of curvature is set to -20 to -30 mm, and the center thickness is 14 to 15 mm;

[0070] The first surface of the sixth lens along the first optical path is a convex surface, the radius of curvature is set to -60 to -70 mm, the second surface is a concave surface, the radius of curvature is set to 430 to 440 mm, and the center thickness is 25 to 30 mm;

[0071] The first surface of the seventh lens along the first optical path is a concave surface, the radius of curvature is set to 220-230 mm, the second surface is a concave surface, the radius of curvature is set to 70-80 mm, and the center thickness is 25-30 mm;

[0072] The first surface of the eighth lens along the first optical path is a convex surface, the radius of curvature is set to -35 to -40 mm, the second surface is a concave surface, the radius of curvature is set to 50 to 60 mm, and the center thickness is 15 to 20 mm;

[0073] The first surface of the ninth lens along the first optical path direction is a convex surface, the radius of curvature is set to -10 to -15 mm, the second surface is a convex surface, the radius of curvature is set to -230 to -240 mm, and the center thickness is 6 to 7 mm;

[0074] The first surface of the tenth lens along the first optical path direction is a plane, the second surface is a plane, and the center thickness is 13-14 mm.

[0075] By adopting the above technical solution, the focus-free transmission lens group realizes focus-free imaging within the refractive range of -15D to +15D through the design of the lens shape combined with the setting of parameters such as the curvature radius and the center thickness.

[0076] Optionally, the gap between the second lens and the first lens is 20-25 mm;

[0077] The gap between the second lens and the third lens is 20-25 mm;

[0078] The gap between the third lens and the fourth lens is 30-35 mm; the gap between the fourth lens and the fifth lens is 35-40 mm;

[0079] The gap between the fifth lens and the sixth lens is 30-35 mm;

[0080] The gap between the sixth lens and the seventh lens is 10 to 15 mm;

[0081] The gap between the seventh lens and the eighth lens is 30-35 mm;

[0082] The gap between the eighth lens and the ninth lens is 1 to 5 mm;

[0083] The gap between the ninth lens and the tenth lens is 1 to 5 mm.

[0084] By adopting the above technical solution, the gap between the lenses of the focus-free transmission lens group is limited, thereby improving the imaging effect.

[0085] Optionally, the light detection module includes a detector 8 and a host computer 9;

[0086] The detector 8 is used to convert the received human eye fundus reflected light into an electrical signal and transmit it to a host computer to obtain a fundus image.

[0087] In this embodiment, the optical detection module includes a detector 8 and a host computer 9. The detector 8 may be a single-pixel detector 8, which is used to convert the received optical signal into an electrical signal and transmit it to the host computer 9, which performs algorithm processing to reconstruct the fundus image. Figure 1 Only one single-pixel detector 8 is shown. In actual use, after the reflected light is split by the spectroscopic module 2, light of different wavelengths reaches different single-pixel detectors 8 for imaging. Figure 2 The figure shows the structure of the focus-free transmission lens group 5 in the fundus imaging device.

[0088] The designed focus-free ellipsoid fundus imaging system was used to perform full-field imaging of human eyes with diopters of -15D, 10D, 0D, 10D, and 15D, respectively, with light sources emitting wavelengths of 488nm, 520nm, 635nm, and 785nm. The full-field point arrays of human eyes with different diopters are shown in the following figure. Figures 3 to 7 As shown, Figure 3 This is the full field of view spot diagram of a human eye with a diopter of -15D. Figure 4 This is the full field of view point diagram of a 10D human eye. Figure 5 is the full field of view point diagram of a normal human eye. Figure 6 This is the full field of view point diagram of a 10D human eye. Figure 7 This is the full field spot diagram of a 15D diopter human eye;

[0089] By Figures 3 to 7 As shown, six fields of view are obtained at each diopter (fields 1 to 6 correspond to object planes extending from 11.98 mm to -11.98 mm in sequence), and the RMS radius for each diopter is shown in Table 1 below:

[0090] Table 1 RMS radius

[0091] -15D -10D 0D 10D 15D Field of view 1 15.503μm 15.115μm 14.753μm 14.954μm 15.259μm Field of View 2 14.858μm 13.879μm 12.562μm 12.827μm 13.299μm Field of view 3 11.789μm 11.959μm 12.307μm 12.666μm 12.849μm Field of view 4 10.111μm 9.765μm 14.209μm 13.933μm 14.270μm Field of view 5 6.723μm 5.609μm 4.863μm 9.410μm 12.162μm Field of view 6 23.189μm 20.957μm 16.813μm 13.789μm 13.101μm

[0092] Combined with Table 1 Figures 3 to 7 It can be seen that the combination of ellipsoidal reflector, focus-free transmission lens group and scanning module realizes focus-free imaging of human eyes with a diopter of -15D to +15D; single imaging with an extraocular field of view angle of 135° (intraocular field of view angle of 200°), and a full-field optical resolution of 23um within the diopter range of -15D to +15D. The entire system has the advantages of ultra-wide angle, high resolution, simple operation and easy manufacturing.

[0093] In the embodiment of the present invention, the characteristic that the light emitted from one focus of the ellipsoidal reflection surface must converge to another focus is utilized. Through the design of the focus-free lens group, the number of lenses is increased after the primary image plane position, the system degree of freedom is increased, and the compensation for diopter is realized; the focus-free lens group can realize the correction of field aberration and compensation of human eye diopter aberration without moving the lens group, and realizes the focus-free imaging of -15D to +15D human eyes, and the ultra-wide-angle multi-wavelength confocal laser scanning fundus imaging with a single extraocular field of view angle of 135° (intraocular field of view angle of 200°). The focus-free lens group can realize the correction of field aberration and compensation of human eye diopter aberration by using the cooperation of multiple ordinary lenses, and the manufacturing cost is lower than that of using free-form surface lenses. It solves the problem that the existing fundus imaging equipment uses mobile lenses for diopter compensation, which has cumbersome operation, the use of free-form surface lenses has high manufacturing cost, and the field of view angle is small, which is easy to cause missed diagnosis of peripheral retinal lesions. It has the advantages of ultra-wide angle, high resolution, simple operation, easy manufacturing and comprehensive detection.

[0094] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A focus-free ellipsoidal fundus imaging system, characterized in that: include: Light source module, light splitting module, light focusing module, scanning module, light detection module, focus-free transmission mirror set and ellipsoidal reflector; The light source module is used to emit light; the light passes through the splitter module, the focusing module, the scanning module, the focus-free transmission mirror group and the ellipsoidal reflector in sequence along the first light path direction, and then reaches the retina of the human eye through the pupil; the reflected light from the fundus of the human eye passes through the ellipsoidal reflector, the focus-free transmission mirror group, the scanning module, the focusing module and the splitter module in sequence along the second light path direction, and is split in the splitter module and incident on the light detection module, and the light detection module converts the light signal into a digital image; The ellipsoidal reflector has a first focus and a second focus, the pupil of the human eye is located at the first focus, and the entrance pupil of the focus-free transmission mirror group is located at the second focus, and the two form a conjugate relationship; the ellipsoidal reflector is used to transmit the incident light to the human eye, and transmit the reflected light of the human eye back to the focus-free transmission mirror group; The focus-free lens group is used to correct the field aberration and compensate for the diopter aberration of the human eye; the focus-free transmission lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens arranged in sequence along the first optical path direction; the eighth lens, the ninth lens and the tenth lens are used to correct the aberration of the reflected light within the 200° field angle of the human eye retina, and converge the field light reflected by the ellipsoidal reflector to form a primary image plane between the sixth lens and the seventh lens; the sixth lens and the seventh lens are used to correct the aberration of the primary imaging plane; the fifth lens and the fourth lens are used to compress the light size to match it with the scanning module and correct the aberration at the same time; the first lens, the second lens and the third lens are used to perform aberration correction on the exit pupil, and adjust the angle between the light and the optical axis of the focus-free transmission lens group so that the light is parallel to the optical axis of the focus-free transmission lens group; The scanning module is used to emit light with different field angles in the same direction; The focusing module is used to convert the incident light in the first light path into parallel light, and to converge the light passing through the scanning module to the light splitting module in the second light path.

2. The system according to claim 1, characterized in that The scanning module uses a two-dimensional galvanometer, and the vibration amplitude of the two-dimensional galvanometer is not greater than 20° 3. The system according to claim 2, characterized in that The center of the scanning module and the focus-free transmission mirror group are on the same optical axis; the reflected light of the focus-free transmission mirror group along the second optical path is reflected by the two-dimensional galvanometer mirror, so that light rays of different fields of view are emitted in the same direction.

4. The system according to claim 1, characterized in that The first lens is a cemented lens, the first surface along the first optical path direction is a convex surface, the radius of curvature is set to -110 to -120 mm, the second surface is a concave surface relative to the first surface, the radius of curvature is set to 15 to 20 mm, the third surface is a concave surface, the radius of curvature is set to 30 to 40 mm, the center thickness between the first surface and the second surface is 3 to 4 mm, and the center thickness between the second surface and the third surface is 6 to 7 mm; The first surface of the second lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -100 to -110 mm, and the center thickness is 9 to 10 mm; The first surface of the third lens along the first optical path is a convex surface, the radius of curvature is set to -100 to -110 mm, the second surface is a convex surface, the radius of curvature is set to -4000 to -4100 mm, and the center thickness is 9 to 10 mm; The first surface of the fourth lens along the first optical path is a concave surface, the radius of curvature is set to 330-340 mm, the second surface is a convex surface, the radius of curvature is set to -60--70 mm, and the center thickness is 10-15 mm; The first surface of the fifth lens along the first optical path is a convex surface, the radius of curvature is set to -40 to -50 mm, the second surface is a convex surface, the radius of curvature is set to -20 to -30 mm, and the center thickness is 14 to 15 mm; The first surface of the sixth lens along the first optical path is a convex surface, the radius of curvature is set to -60 to -70 mm, the second surface is a concave surface, the radius of curvature is set to 430 to 440 mm, and the center thickness is 25 to 30 mm; The first surface of the seventh lens along the first optical path is a concave surface, the radius of curvature is set to 220-230 mm, the second surface is a concave surface, the radius of curvature is set to 70-80 mm, and the center thickness is 25-30 mm; The first surface of the eighth lens along the first optical path is a convex surface, the radius of curvature is set to -35 to -40 mm, the second surface is a concave surface, the radius of curvature is set to 50 to 60 mm, and the center thickness is 15 to 20 mm; The first surface of the ninth lens along the first optical path direction is a convex surface, the radius of curvature is set to -10 to -15 mm, the second surface is a convex surface, the radius of curvature is set to -230 to -240 mm, and the center thickness is 6 to 7 mm; The first surface of the tenth lens along the first optical path direction is a plane, the second surface is a plane, and the center thickness is 13-14 mm.

5. The system according to claim 1, wherein: The gap between the second lens and the first lens is 20-25 mm; The gap between the second lens and the third lens is 20-25 mm; The gap between the third lens and the fourth lens is 30-35 mm; the gap between the fourth lens and the fifth lens is 35-40 mm; The gap between the fifth lens and the sixth lens is 30-35 mm; The gap between the sixth lens and the seventh lens is 10 to 15 mm; The gap between the seventh lens and the eighth lens is 30-35 mm; The gap between the eighth lens and the ninth lens is 1 to 5 mm; The gap between the ninth lens and the tenth lens is 1 to 5 mm.

6. The system according to claim 1, characterized in that The light source module is one of a single-wavelength light source and a multi-wavelength light source.

7. The system according to claim 6, characterized in that The light source module emits lasers with wavelengths of 488nm, 520nm, 635nm and 785nm.

8. The system of claim 1, wherein: The beam splitter module is a beam splitter or a beam splitter group; the beam splitter is a cube beam splitter or a flat beam splitter.

9. The system according to claim 1, characterized in that The light detection module includes a detector and a host computer; The detector is used to convert the received human eye fundus reflected light into an electrical signal and transmit it to a host computer to obtain a fundus image.

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