Portable large field of view fundus camera optical system

Abstract

The present application relates to a kind of portable large field of view fundus camera optical system, which uses four-piece as retinal objective, improves Gaussian mirror group as imaging mirror group, uses secondary imaging, and the retina is first imaged in the center of the system through retinal objective, and the central image is finally imaged in CMOS sensor through focusing mirror group and imaging mirror group, and finally clear fundus image is obtained. At the same time, a flat-concave lens is used as the focusing lens in the Gaussian mirror group. The optical design of the system is simple in structure, low in manufacturing cost, and compared with the portable fundus camera on the market, the number of lenses is less, and no aspherical mirror is used to meet the requirements of large field of view and wide range of focusing. The system length is less than 190mm, which meets the requirements of portability.

Description

Technical Field

[0001] The present invention relates to the field of ophthalmic optical instruments, and in particular to a portable large-field-of-view fundus camera optical system. Background Art

[0002] As the only tissue in the body where blood vessels and their distribution can be observed non-invasively in vivo, the retina has become a crucial window for diagnosing eye diseases and related systemic disorders. The most common ophthalmic conditions include cataracts, glaucoma, and conjunctivitis. Beyond the visual manifestations of these ophthalmic lesions, retinal capillary lesions can provide early diagnosis of conditions such as hypertension, diabetes, and thrombosis. In today's society, with improved living standards, more and more people are becoming more aware of their health. Retinal vascular status serves as a pathological basis for fundus health and common diseases. If fundus cameras can be widely used in communities, schools, and even homes, they will have significant medical value for early health screening.

[0003] At present, the focusing range of portable fundus cameras is mainly ±10D, and the field of view angle is mainly 30°-40°. There are problems such as small focusing range, small field of view, and high cost. Moreover, due to the limitation of field of view, most of the retinal objective lenses are aspherical. In addition, the design process needs to meet the requirements of portability and high resolution at the same time, and the system volume is limited. As a result, it is difficult to take both the field of view range and the focusing range into account at the same time during the design process. For example, the fundus camera in the reference "Optical Design of a New Portable Fundus Camera" has a focusing range of ±15D, but its field of view angle is only 40°[1]. The fundus camera provided in "Research and Development Design of Fundus Camera Optical Device System Based on Mobile Device" has a field of view angle of 50°, but its focusing range is only ±10D[2]. The field of view angle of a new type of non-mydriatic portable fundus camera is 60°, but its focusing range is only -8D to +10D[3].

[0004] References:

[0005] [1] Hong Yang. Optical design of a new portable fundus camera[D]. Jiangsu: Soochow University, 2021.

[0006] [2] Dong Ruya, Hong Chaoyang, Zheng Qingqing, et al. Research and development of fundus camera optical device system based on mobile device[J]. China Medical Equipment, 2022(007):019.

[0007] [3] Liu Yue, Yang Qiang, Wang Qingfeng, et al. A new portable fundus camera without mydriasis. 2012[2024-10-16].

[0008] Existing fundus cameras are still difficult to use on a large scale to meet fundus screening requirements and cover remote areas for screening activities. Therefore, it is particularly important to design a portable fundus camera with a large field of view, simple structure, large focusing range, low cost and high resolution. Summary of the Invention

[0009] In view of the above-mentioned deficiencies in the prior art, the present invention designs an optical imaging system based on the Gullstrand-Le Grand100 eye model, and provides an optical imaging system that can achieve a large field of view and meet the needs of short-distance and large-range focusing.

[0010] The specific technical solutions of the present invention are as follows:

[0011] A portable large-field fundus camera optical system comprises a retina objective lens, a focusing lens group and an imaging lens group which are arranged on the same optical axis from left to right;

[0012] The retina objective lens comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence from left to right; the first lens is a meniscus lens, the second lens is a biconvex lens, and the third lens and the fourth lens are combined into a doublet lens;

[0013] The focusing lens assembly includes a fifth lens, and the fifth lens is a plano-concave lens;

[0014] The imaging lens group includes a front imaging lens group and a rear imaging lens group arranged in sequence from left to right; the front imaging lens group includes a sixth lens, a seventh lens, and an eighth lens arranged in sequence from left to right, the sixth lens is a plano-convex lens, and the seventh lens and the eighth lens constitute a doublet lens; the rear imaging lens group includes a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from left to right, the ninth lens and the tenth lens constitute a doublet lens, the eleventh lens is a meniscus lens, and the twelfth lens is a positive lens.

[0015] Preferably, from left to right, the first lens has a first lens surface and a second lens surface in sequence; the second lens has a third lens surface and a fourth lens surface; the third lens and the fourth lens have a fifth lens surface, a sixth lens surface and a seventh lens surface, the first lens surface is convex to the right, and the curvature radius thereof is in the range of [122.31 mm, 123.31 mm]; the second lens surface is convex to the right, and the curvature radius thereof is in the range of [41.9 mm, 42.9 mm]; the third lens surface is convex to the left, and the curvature radius thereof is in the range of The fourth lens surface is convex to the right, and the curvature radius range is [68.53mm, 69.53mm]; the fifth lens surface is convex to the left, and the curvature radius range is [57.55mm, 58.55mm]; the sixth lens surface is convex to the right, and the curvature radius range is [54.83mm, 55.83mm]; the seventh lens surface is convex to the right, and the curvature radius range is [520.24mm, 521.24mm].

[0016] Preferably, the thickness range of the first lens is [10.25mm, 11.25mm], the thickness range of the second lens is [10.61mm, 11.61mm], the thickness range of the third lens is [14.76mm, 15.76mm], and the thickness range of the fourth lens is [4.43mm, 5.43mm].

[0017] Preferably, the glass material of the first lens is H-LAK3; the glass material of the second lens is H-ZPK5; the glass material of the third lens is H-ZPK5; and the glass material of the fourth lens is H-ZF62GT.

[0018] Preferably, the fifth lens has an eighth lens surface and a ninth lens surface in sequence; the eighth lens surface is a plane; the ninth lens surface is convex toward the left, and its curvature radius ranges from [18.46 mm, 19.46 mm].

[0019] Preferably, the thickness range of the fifth lens is [2.15 mm, 3.15 mm].

[0020] Preferably, the glass material of the fifth lens is H-LAK2A.

[0021] Preferably, from left to right, the sixth lens has a tenth lens surface and an eleventh lens surface in sequence, the seventh lens and the eighth lens have a twelfth lens surface, a thirteenth lens surface, and a fourteenth lens surface in sequence, the ninth lens and the tenth lens have a fifteenth lens surface, a sixteenth lens surface, and a seventeenth lens surface in sequence, the eleventh lens has an eighteenth lens surface and a nineteenth lens surface in sequence, and the twelfth lens has a twentieth lens surface and a twenty-first lens surface in sequence; the tenth lens surface is convex to the left, and its curvature radius ranges from [22.19 mm, 23.19 mm]; the eleventh lens surface is a plane; the twelfth lens surface is convex to the left, and its curvature radius ranges from [9.52 mm, 10.52 mm]; the thirteenth lens surface is convex to the right, and its curvature radius ranges from [8.25 mm, 9.25 mm]; the fourteenth lens surface is convex to the left, and its curvature ranges from [ The radius range is [21.32mm, 22.32mm]; the fifteenth lens surface is convex to the right, and the curvature radius range is [10.25mm, 11.25mm]; the sixteenth lens surface is convex to the left, and the curvature radius range is [4.34mm, 5.34mm]; the seventeenth lens surface is convex to the right, and the curvature radius range is [6.75mm, 7.75mm]; the eighteenth lens surface is convex to the right, and the curvature radius range is [5.26mm, 6.26mm]; the nineteenth lens surface is convex to the right, and the curvature radius range is [22.81mm, 23.81mm]; the twentieth lens surface is convex to the left, and the curvature radius range is [15.13mm, 16.13mm]; the twenty-first lens surface is convex to the left, and the curvature radius range is [93.17mm, 94.17mm].

[0022] Preferably, the thickness range of the sixth lens is [9.11 mm, 10.11 mm], the thickness range of the seventh lens is [7.8 mm, 8.8 mm], the thickness range of the eighth lens is [1.1 mm, 2.1 mm], the thickness range of the ninth lens is [3.16 mm, 4.16 mm], the thickness range of the tenth lens is [2.23 mm, 3.23 mm], the thickness range of the eleventh lens is [1.9 mm, 2.9 mm], and the thickness range of the twelfth lens is [7.62 mm, 8.62 mm].

[0023] Preferably, the glass material of the sixth lens is H-ZLAF50E; the glass material of the seventh lens is H-ZPK5; the glass material of the eighth lens is H-K3; the glass material of the ninth lens is H-F1; the glass material of the tenth lens is H-ZPK7; the glass material of the eleventh lens is H-ZF12; and the glass material of the twelfth lens is H-ZLAF75A.

[0024] The beneficial effects of the present invention are:

[0025] The present invention designs a fundus shaping optical imaging system based on the Gullstrand-Le Grand100 eye model, which can achieve a large field of view and meet the requirements of short-distance and large-range focusing optical imaging. It has the following advantages:

[0026] 1. The secondary imaging method is adopted, using a four-piece retina objective lens to form an image in the center, and then the secondary imaging is achieved through the imaging lens group, which reduces the distortion caused by the large field of view and eliminates the need for aspheric surfaces.

[0027] 2. Combining a four-piece retina objective lens with an optimized Gaussian lens group to achieve a large field of view, high-resolution imaging system.

[0028] 3. Plano-concave lenses are used to eliminate aberrations and serve as the system's focusing lens group to meet the needs of focusing over a wide range and short distances.

[0029] 4. The instrument's optical design is simple and cost-effective. Compared to commercially available portable fundus cameras, this design uses fewer lenses and eliminates the use of aspheric lenses, yet still meets the requirements for a wide field of view and wide focusing range. The fundus camera optical system of the present invention boasts a wide field of view (FOV) of up to 53.13°, a simple structure, and a system length of less than 190 mm, meeting portability requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the optical system structure of the portable large-field-of-view fundus camera of the present invention;

[0031] Figure 2 This is a schematic diagram of imaging using a portable large-field-of-view fundus camera according to the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form.

[0033] refer to Figure 1 The portable, wide-field-of-view fundus camera optical system of the present invention is designed based on the Gullstrand-Le Grand eye model. It includes a retinal objective lens, a focusing lens assembly, and an imaging lens assembly. These three lenses are arranged coaxially from left to right.

[0034] The retina objective lens 200 includes a first lens 210, a second lens 220, a third lens 230 and a fourth lens 240 arranged from left to right. The first lens 210 is a meniscus lens, the second lens 220 is a biconvex lens, and the third lens 230 and the fourth lens 240 are combined into a doublet lens.

[0035] The focusing lens assembly 300 includes a fifth lens 310 , which is a plano-concave lens.

[0036] The imaging lens group 400 includes a front imaging lens group and a rear imaging lens group; the front imaging lens group includes a sixth lens 420, a seventh lens 430, and an eighth lens 440. The sixth lens 420 is a plano-convex lens, and the seventh lens 430 and the eighth lens 440 form a doublet lens; the rear imaging lens group includes a ninth lens 450, a tenth lens 460, an eleventh lens 470, and a twelfth lens 480. The ninth lens 450 and the tenth lens 460 form a doublet lens, the eleventh lens 470 is a meniscus lens, and the twelfth lens 480 is a positive lens.

[0037] The system uses a four-element retinal objective lens and an improved Gaussian lens assembly as the imaging lens group. Using secondary imaging, the retina is first imaged at the center of the system by the retinal objective lens. The central image then passes through the focusing lens group and the imaging lens group, ultimately forming a picture on the CMOS sensor 500, ultimately acquiring a clear fundus image. A plano-concave lens is used as the focusing lens in the Gaussian lens group, enabling wide-range, short-distance focusing.

[0038] From left to right, the first lens 210 has a first lens surface 201 and a second lens surface 202 in sequence; the second lens 220 has a third lens surface 203 and a fourth lens surface 204; the third lens 230 and the fourth lens 240 have a fifth lens surface 205, a sixth lens surface 206 and a seventh lens surface 207; the fifth lens 310 has an eighth lens surface 301 and a ninth lens surface 302 in sequence; the sixth lens 420 has a tenth lens surface 401 and an eleventh lens surface 402 in sequence; the seventh lens 430 and the eighth lens 440 have a twelfth lens surface 403, a thirteenth lens surface 404 and a fourteenth lens surface 405 in sequence; the ninth lens 450 and the tenth lens 460 have a fifteenth lens surface 406, a sixteenth lens surface 407 and a seventeenth lens surface 408 in sequence; the eleventh lens 470 has an eighteenth lens surface 409 and a nineteenth lens surface 410 in sequence; and the twelfth lens 480 has a twentieth lens surface 411 and a twenty-first lens surface 412 in sequence.

[0039] The first lens surface 201 is convex toward the right, and its radius of curvature ranges from [122.31mm, 123.31mm]; the second lens surface 202 is convex toward the right, and its radius of curvature ranges from [41.9mm, 42.9mm]; the third lens surface 203 is convex toward the left, and its radius of curvature ranges from [319.07mm, 320.07mm]; the fourth lens surface 204 is convex toward the right, and its radius of curvature ranges from [68.53mm, 69.53mm]; the fifth lens surface 205 is convex toward the left, and its radius of curvature ranges from [57.55mm, 58.55mm]; the sixth lens surface 206 is convex toward the right, and its radius of curvature ranges from [54.83mm, 55.83mm]; and the seventh lens surface 207 is convex toward the right, and its radius of curvature ranges from [520.24mm, 521.24mm].

[0040] The eighth lens surface 301 is a plane; the ninth lens surface 302 is convex toward the left, and its curvature radius ranges from [18.46 mm to 19.46 mm].

[0041] The tenth lens surface 401 is convex toward the left, and its radius of curvature is in the range of [22.19mm, 23.19mm]; the eleventh lens surface 402 is flat; the twelfth lens surface 403 is convex toward the left, and its radius of curvature is in the range of [9.52mm, 10.52mm]; the thirteenth lens surface 404 is convex toward the right, and its radius of curvature is in the range of [8.25mm, 9.25mm]; the fourteenth lens surface 405 is convex toward the left, and its radius of curvature is in the range of [21.32mm, 22.32mm]; the fifteenth lens surface 406 is convex toward the right, and its radius of curvature is in the range of [10.25mm, 11.25mm]; the sixteenth lens surface 407 is convex toward the left The seventeenth lens surface 408 is convex toward the right, and the curvature radius range is [4.34mm, 5.34mm]; the seventeenth lens surface 408 is convex toward the right, and the curvature radius range is [6.75mm, 7.75mm]; the eighteenth lens surface 409 is convex toward the right, and the curvature radius range is [5.26mm, 6.26mm]; the nineteenth lens surface 410 is convex toward the right, and the curvature radius range is [22.81mm, 23.81mm]; the twentieth lens surface 411 is convex toward the left, and the curvature radius range is [15.13mm, 16.13mm]; the twenty-first lens surface 412 is convex toward the left, and the curvature radius range is [93.17mm, 94.17mm].

[0042] The thickness of the first lens 210 is in the range of [10.25 mm, 11.25 mm], the thickness of the second lens 220 is in the range of [10.61 mm, 11.61 mm], the thickness of the third lens 230 is in the range of [14.76 mm, 15.76 mm], the thickness of the fourth lens 240 is in the range of [4.43 mm, 5.43 mm], and the thickness of the fifth lens 310 is in the range of [2.15 mm, 3.15 mm]. The thickness range of the sixth lens 420 is [9.11 mm, 10.11 mm], the thickness range of the seventh lens 430 is [7.8 mm, 8.8 mm], the thickness range of the eighth lens 440 is [1.1 mm, 2.1 mm], the thickness range of the ninth lens 450 is [3.16 mm, 4.16 mm], the thickness range of the tenth lens 460 is [2.23 mm, 3.23 mm], the thickness range of the eleventh lens 470 is [1.9 mm, 2.9 mm], and the thickness range of the twelfth lens 480 is [7.62 mm, 8.62 mm].

[0043] The glass material of the first lens 210 is H-LAK3; the glass material of the second lens 220 is H-ZPK5; the glass material of the third lens 230 is H-ZPK5; the glass material of the fourth lens 240 is H-ZF62GT. The glass material of the fifth lens 310 is H-LAK2A. The glass material of the sixth lens 420 is H-ZLAF50E; the glass material of the seventh lens 430 is H-ZPK5; the glass material of the eighth lens 440 is H-K3; the glass material of the ninth lens 450 is H-F1; the glass material of the tenth lens 460 is H-ZPK7; the glass material of the eleventh lens 470 is H-ZF12; and the glass material of the twelfth lens 480 is H-ZLAF75A.

[0044] Example 1

[0045] In a specific embodiment of the present invention, the curvature radius, thickness and material of each lens surface and lens of the portable large-field-of-view fundus camera optical system of the present invention are shown in Table 1-2.

[0046] Table 1 Curvature radius of each lens surface

[0047]

[0048]

[0049] Note: Here, it is assumed that the lens surface and the principal optical axis produce an intersection. If the center of the sphere where the lens surface is located is on the left of the intersection, then the curvature radius of the lens surface is negative. Conversely, if the center of the sphere where the lens surface is located is on the right of the intersection, then the curvature radius of the lens surface is positive.

[0050] Table 2 Lens thickness and material

[0051] lens Thickness / (mm) Glass material First lens 210 11.25 H-LAK3 Second lens 220 11.61 H-ZPK5 The third lens 230 15.76 H-ZPK5 Fourth lens 240 5.43 H-ZF62GT Fifth lens 310 3.15 H-LAK2A Sixth lens 420 10.11 H-ZLAF50E Seventh lens 430 8.8 H-ZPK5 Eighth lens 440 2.1 H-K3 Ninth lens 450 4.16 H-F1 Tenth lens 460 3.23 H-ZPK7 Eleventh lens 470 2.9 H-ZF12 Twelfth lens 480 8.62 H-ZLAF75A

[0052] Testing of the optical system of the above embodiment revealed that when the Nyquist frequency was 145 lp / mm, the modulation transfer function (MTF) of the imaging system was 0.3. Furthermore, the distance between the image plane and the twenty-first lens surface 412 of the optical system in this embodiment was 11.6 mm; the distance between the image plane and the first lens surface 201 of this embodiment was 190 mm; and the distance between the first lens surface 201 and the human eye model 100 was 38 mm. The focusing range of the optical system in this embodiment was ±20D. When the focus was +20D and the Nyquist frequency was 145 lp / mm, the modulation transfer function (MTF) of the imaging system was 0.2; when the focus was -20D and the Nyquist frequency was 145 lp / mm, the modulation transfer function (MTF) of the imaging system was 0.2. In this embodiment, when the focus was +20D, the distance between the eighth lens surface and the seventh lens surface was 11.6 mm. When the focus was -20D, the distance between the eighth lens surface and the seventh lens surface was 16.4 mm. The total focusing distance is 4.8mm.

[0053] Table 3 Modern optical processing levels

[0054]

[0055] To verify this optical system, 1000 Monte Carlo tests were performed on the system, using the Q6 tolerance coefficients of modern optical processing. The imaging system's modulation transfer function (MTF) at a Nyquist frequency of 145 lp / mm (or equivalent) was used as the criterion for analysis. The focusing lens was used as a compensator, with a compensation range of ±0.2. When the focusing lens assembly was positioned at 0 degrees, the Monte Carlo test yielded a 98% probability of achieving a MTF of 0.256 at a Nyquist frequency of 145 lp / mm. When the focusing lens assembly was positioned at +20 degrees, the Monte Carlo test yielded a 98% probability of achieving a MTF of 0.226 at a Nyquist frequency of 145 lp / mm. When the focusing lens assembly was positioned at -20 degrees, the Monte Carlo test yielded a MTF of 0.213 at a Nyquist frequency of 145 lp / mm (or equivalent).

[0056] Furthermore, the system is tested by actual processing, such as Figure 2As shown, a target is placed 1m + 38mm from the system, where 38mm represents the theoretical distance between the system and the human eye model. Testing shows that the image is captured at a height of 1.02m. Using the triangle sine function, the system's field of view is 53.13°, meeting the wide field of view requirement. The system length does not exceed 190mm, making it portable. Furthermore, the internal focusing range is ±20D, and the focusing lens group travels a distance of 4.8mm. The camera's simple structure and the use of spherical lenses contribute to its low cost.

[0057] The technical features of the above-described embodiments can be combined in any combination. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent of this invention shall be based on the attached claims.

Claims

1. A portable large-field-of-view fundus camera optical system comprising a retinal objective lens, a focusing lens assembly, and an imaging lens assembly, arranged coaxially from left to right, characterized in that: The retina objective lens (200) comprises a first lens (210), a second lens (220), a third lens (230) and a fourth lens (240) arranged in sequence from left to right; the first lens (210) is a meniscus lens, the second lens (220) is a biconvex lens, and the third lens (230) and the fourth lens (240) are combined into a double cemented lens; from left to right, the first lens (210) has a first lens surface (201) and a second lens surface (202) in sequence; the second lens (220) has a third lens surface (203) and a fourth lens surface (204); the third lens (230) and the fourth lens (240) have a fifth lens surface (205), a sixth lens surface (206) and a seventh lens surface (207); The first lens surface (201) is convex toward the right, and its curvature radius range is [122.31mm, 123.31mm]; the second lens surface (202) is convex toward the right, and its curvature radius range is [41.9mm, 42.9mm]; the third lens surface (203) is convex toward the left, and its curvature radius range is [319.07mm, 320.07mm]; the fourth lens surface (204) is convex toward the right, and its curvature radius range is [ The radius range is [68.53mm, 69.53mm]; the fifth lens surface (205) is convex toward the left, and the curvature radius range is [57.55mm, 58.55mm]; the sixth lens surface (206) is convex toward the right, and the curvature radius range is [54.83mm, 55.83mm]; the seventh lens surface (207) is convex toward the right, and the curvature radius range is [520.24mm, 521.24mm]; The focusing lens group (300) includes a fifth lens (310), the fifth lens (310) is a plano-concave lens; the fifth lens (310) has an eighth lens surface (301) and a ninth lens surface (302) in sequence; the eighth lens surface (301) is a plane; the ninth lens surface (302) is convex toward the left, and its curvature radius ranges from [18.46 mm to 19.46 mm]. The imaging lens group (400) comprises a front imaging lens group and a rear imaging lens group arranged in sequence from left to right; The front imaging lens group comprises a sixth lens (420), a seventh lens (430), and an eighth lens (440) arranged in sequence from left to right, the sixth lens (420) is a plano-convex lens, and the seventh lens (430) and the eighth lens (440) form a doublet lens; The rear imaging lens group comprises a ninth lens (450), a tenth lens (460), an eleventh lens (470), and a twelfth lens (480) arranged in sequence from left to right, wherein the ninth lens (450) and the tenth lens (460) form a doublet lens, the eleventh lens (470) is a meniscus lens, and the twelfth lens (480) is a positive lens; From left to right, the sixth lens (420) has a tenth lens surface (401) and an eleventh lens surface (402) in sequence, the seventh lens (430) and the eighth lens (440) have a twelfth lens surface (403), a thirteenth lens surface (404), and a fourteenth lens surface (405) in sequence, the ninth lens (450) and the tenth lens (460) have a fifteenth lens surface (406), a sixteenth lens surface (407), and a seventeenth lens surface (408) in sequence, the eleventh lens (470) has an eighteenth lens surface (409) and a nineteenth lens surface (410) in sequence, and the twelfth lens (480) has a twentieth lens surface (411) and a twenty-first lens surface (412) in sequence; The tenth lens surface (401) is convex toward the left, and its curvature radius range is [22.19mm, 23.19mm]; the eleventh lens surface (402) is a plane; the twelfth lens surface (403) is convex toward the left, and its curvature radius range is [9.52mm, 10.52mm]; the thirteenth lens surface (404) is convex toward the right, and its curvature radius range is [8.25mm, 9.25mm]; the fourteenth lens surface (405) is convex toward the left, and its curvature radius range is [21.32mm, 22.32mm]; the fifteenth lens surface (406) is convex toward the right, and its curvature radius range is [10.25mm, 11.25mm]; the sixteenth lens surface (407) is convex toward the right The seventeenth lens surface (408) is convex toward the right, and its curvature radius range is [4.34mm, 5.34mm]; the seventeenth lens surface (408) is convex toward the right, and its curvature radius range is [6.75mm, 7.75mm]; the eighteenth lens surface (409) is convex toward the right, and its curvature radius range is [5.26mm, 6.26mm]; the nineteenth lens surface (410) is convex toward the right, and its curvature radius range is [22.81mm, 23.81mm]; the twentieth lens surface (411) is convex toward the left, and its curvature radius range is [15.13mm, 16.13mm]; the twenty-first lens surface (412) is convex toward the left, and its curvature radius range is [93.17mm, 94.17mm].

2. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The thickness range of the first lens (210) is [10.25 mm, 11.25 mm], the thickness range of the second lens (220) is [10.61 mm, 11.61 mm], the thickness range of the third lens (230) is [14.76 mm, 15.76 mm], and the thickness range of the fourth lens (240) is [4.43 mm, 5.43 mm].

3. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The glass material of the first lens (210) is H-LAK3; the glass material of the second lens (220) is H-ZPK5; the glass material of the third lens (230) is H-ZPK5; and the glass material of the fourth lens (240) is H-ZF62GT.

4. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The thickness range of the fifth lens (310) is [2.15 mm, 3.15 mm].

5. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The glass material of the fifth lens (310) is H-LAK2A.

6. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The thickness range of the sixth lens (420) is [9.11mm, 10.11mm], the thickness range of the seventh lens (430) is [7.8mm, 8.8mm], the thickness range of the eighth lens 440 is [1.1mm, 2.1mm], the thickness range of the ninth lens (450) is [3.16mm, 4.16mm], the thickness range of the tenth lens (460) is [2.23mm, 3.23mm], the thickness range of the eleventh lens (470) is [1.9mm, 2.9mm], and the thickness range of the twelfth lens (480) is [7.62mm, 8.62mm].

7. The portable large-field-of-view fundus camera optical system according to claim 1, characterized in that: The glass material of the sixth lens (420) is H-ZLAF50E; the glass material of the seventh lens (430) is H-ZPK5; the glass material of the eighth lens (440) is H-K3; the glass material of the ninth lens (450) is H-F1; the glass material of the tenth lens (460) is H-ZPK7; the glass material of the eleventh lens (470) is H-ZF12; and the glass material of the twelfth lens (480) is H-ZLAF75A.

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