Wide-angle imaging lens module for fundus retina imaging

Abstract

The invention provides a wide-angle imaging lens module for fundus retina imaging, and the wide-angle imaging lens module sequentially comprises a first lens with first negative refraction focal power D1 and a first dispersion coefficient Vd1 from left to right, and the left surface and the right surface of the first lens are spherical surfaces; the second lens has second positive refraction focal power D2 and a second dispersion coefficient Vd2, the left surface of the second lens is a spherical surface, and the right surface of the second lens is an aspheric surface; the third lens has third positive refraction focal power D3 and a second dispersion coefficient, and the left surface and the right surface of the second lens are aspheric surfaces; wherein the first lens and the second lens are glued together and meet the following formulas: 0.45 < = D12 / D3 < = 0.65, 1.5 < = Vd1 / Vd2 < = 2.5, and D12 is the combined focal power of the first lens and the second lens. Through the combination of a plurality of lenses and the reasonable setting of the focal power and the dispersion coefficient of the lenses, the observation range of the fundus retina is enlarged and can reach 170-180 degrees.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging, and particularly to a wide-angle imaging lens module for fundus retina imaging. Background Art

[0002] With the aging of the population, changes in the environment and lifestyle, the number of patients with visual impairment and blindness has increased sharply. In order to support the detection, diagnosis and analysis of ophthalmic diseases and provide a basis for adjusting the treatment plan of ophthalmic diseases, higher requirements have been continuously put forward for ophthalmic diagnosis and treatment instruments and methods. Therefore, the demand for ophthalmic diagnosis and treatment is rigid, and fundus examination is one of the basic ophthalmic examinations and plays an important role in the early diagnosis of ophthalmic diseases. Specifically, fundus examination is a method of examining the posterior part of the eyeball, such as the vitreous body, retina, choroid and optic nerve, using a special instrument with illumination and magnification devices.

[0003] Being able to observe the fundus retina of the human eye over a large range has always been an important requirement in this field. However, some of the currently disclosed optical lens systems can at most image the fundus within a range of about 160°. Therefore, in order to achieve better examination results, a lens system with a wider fundus retina examination range is needed. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a wide-angle imaging lens module for fundus retina imaging, which mainly solves the problem that there is a lack of a wide-angle imaging lens module for fundus retina imaging in the prior art.

[0005] The object of the present invention is achieved through the following solutions:

[0006] According to an embodiment of the present invention, there is provided a wide-angle imaging lens module for fundus retina imaging, which sequentially includes from left to right: a first lens having a first negative refractive power D1 and a first dispersion coefficient Vd1, wherein both the left and right surfaces of the first lens are spherical surfaces; a second lens having a second positive refractive power D2 and a second dispersion coefficient Vd2, wherein the left surface of the second lens is a spherical surface and the right surface is an aspherical surface; a third lens having a third positive refractive power D3 and a second dispersion coefficient, wherein both the left and right surfaces of the second lens are aspherical surfaces; wherein, the first lens and the second lens are cemented together and satisfy the following formulas:

[0007] 0.45 ≤ D12 / D3 ≤ 0.65,

[0008] 1.5 ≤ Vd1 / Vd2 ≤ 2.5,

[0009] wherein, D12 is the combined refractive power of the first lens and the second lens.

[0010] According to an embodiment of the present invention, the left surface of the first lens is a concave spherical surface for contacting the eyeball cornea.

[0011] According to an embodiment of the present invention, the radius of curvature of the concave spherical surface is determined based on the size of the eyeball.

[0012] According to an embodiment of the present invention, the radius of curvature is 7.5 - 9 mm.

[0013] According to an embodiment of the present invention, the first lens is made of a light-transmitting material with biocompatibility.

[0014] According to an embodiment of the present invention, the light-transmitting material with biocompatibility includes optical glass, quartz glass, and optical resin.

[0015] According to an embodiment of the present invention, the radius of curvature of the right surface of the first lens is the same as the radius of curvature of the left surface of the second lens.

[0016] According to an embodiment of the present invention, the radius of curvature is 11 - 12 mm.

[0017] According to an embodiment of the present invention, the aspherical lens surface profile is as follows:

[0018]

[0019] Wherein, x is the sagittal height of the lens surface profile, used to describe the height of each point on each aspherical surface in the optical axis direction; h is the aperture of the lens, used to describe the distance of each point on each aspherical surface perpendicular to the optical axis direction; c is the curvature of the vertex of each aspherical surface; k is the aspherical coefficient of each aspherical surface; Ai is the high-order aspherical coefficient of each aspherical surface, and i represents the power.

[0020] According to an embodiment of the present invention, D12 = 42.2, D3 = 74.9, Vd1 = 63.3, and Vd2 = 32.3.

[0021] Compared with the prior art, the present invention has the following beneficial effects: By combining multiple lenses and reasonably setting the optical power and dispersion coefficient of the lenses, the observation range of the fundus retina is increased, and it can reach a range of 170° to 180°; in addition, through the arrangement of aspherical lenses, the imaging quality of the lens system is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following further describes the embodiments of the present invention with reference to the accompanying drawings:

[0023] Figure 1 It is a schematic diagram of the composition of the wide-angle imaging lens module according to the embodiment of the present invention;

[0024] Figure 2Schematic diagram of the light path passing through the human eye-wide-angle imaging lens module according to an embodiment of the present invention;

[0025] Figure 3 Spherical aberration curve graph of the wide-angle imaging lens module according to an embodiment of the present invention;

[0026] Figure 4 Field curvature and distortion curve graph of the wide-angle imaging lens module according to an embodiment of the present invention. Detailed implementation manners

[0027] Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms "coupled", "connected" and their derivatives refer to any direct or indirect communication or connection between two or more elements, regardless of whether those elements are in physical contact with each other. The terms "transmit", "receive" and "communicate" and their derivatives cover both direct and indirect communication. The terms "comprise" and "include" and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with" and its derivatives mean including, included within, interconnected, containing, contained within, connected or coupled with, communicating with, cooperating with, interwoven, juxtaposed, adjacent, bound or bound to, having, having an attribute, having a relationship or having a relationship with, etc. The term "controller" refers to any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware, or in a combination of hardware and software and / or firmware. The functions associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one", when used in conjunction with a list of items, means that different combinations of one or more of the listed items can be used, and it may only be necessary to have one item in the list. For example, "at least one of A, B, C" includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0028] Definitions of other specific words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many cases, if not most cases, such definitions apply to the previous and future use of the words and phrases so defined.

[0029] In this patent document, the application combination of modules and the hierarchical division of sub-modules are only for illustration purposes. Without departing from the scope of the present disclosure, the application combination of modules and the hierarchical division of sub-modules can have different forms.

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] As described in the background art, there is a lack of a lens system in the prior art that can achieve a wider range of fundus retina examinations. To address this problem, as Figure 1 shown, according to an embodiment of the present invention, a wide-angle imaging lens module for fundus retina imaging is provided, which sequentially includes from left to right: a first lens 10, having a first negative refractive power D1 and a first dispersion coefficient Vd1, wherein the left surface S1 and the right surface S2 of the first lens are both spherical surfaces; a second lens 20, having a second positive refractive power D2 and a second dispersion coefficient Vd2, wherein the left surface of the second lens is a spherical surface S2 and the right surface is an aspherical surface S3; a third lens 30, having a third positive refractive power D3 and a second dispersion coefficient, wherein the left surface S4 and the right surface S5 of the second lens are both aspherical surfaces; wherein, the first lens 10 and the second lens 20 are glued together and satisfy the following formula:

[0032] 0.45 ≦ D12 / D3 ≦ 0.65,

[0033] 1.5 ≦ Vd1 / Vd2 ≦ 2.5,

[0034] wherein, D12 is the combined refractive power of the first lens 10 and the second lens 20. By combining multiple lenses and reasonably setting the refractive power and dispersion coefficient of the lenses, the observation range of the fundus retina is increased, and a range of 170° to 180° can be achieved; in addition, the imaging quality of the lens system is enhanced through the arrangement of aspherical lenses.

[0035] To better adapt to the examination of the human eye, referring to Figure 2 , according to an embodiment of the present invention, the left surface of the first lens 10 is a concave spherical surface to contact the eye cornea. The process of the wide-angle imaging lens module imaging the fundus is as follows: Light travels from left to right, the light reflected by the retina 100 passes through the vitreous body 90, then through the eye lens 80, then through the pupil 70, the anterior chamber 60, and the cornea 50. Among them, the retina 100 is the object surface, and the vitreous body 90, the lens 80, the anterior chamber 70, and the cornea 60 are the intraocular refractive media. The pupil 70 is the aperture stop of the entire imaging optical path. After the light emitted by the retina exits the eye, it passes through the first lens 10, the second lens 20, and the third lens 40, and finally forms an image on the real image plane 40. The image plane 40 is an inverted image of the retina 100.

[0036] Similarly, for better adaptation to the human eye, according to an embodiment of the present invention, the radius of curvature of the concave spherical surface is determined based on the size of the eye. Exemplarily, according to an embodiment of the present invention, the radius of curvature is 7.5 - 9 mm.

[0037] In addition, to ensure the safety of the human eye in contact therewith, according to an embodiment of the present invention, the first lens is made of a light-transmitting material with biocompatibility. Exemplarily, according to an embodiment of the present invention, the light-transmitting materials with biocompatibility include optical glass, quartz glass, and optical resin. In addition, for other lenses that do not directly contact the eye, other light-transmitting materials with a wider range can be selected.

[0038] Furthermore, to ensure the function and stability of the cemented lens (i.e., the combination of the first lens and the second lens), according to an embodiment of the present invention, the radius of curvature of the right surface of the first lens is the same as the radius of curvature of the left surface of the second lens. In addition, to ensure the imaging performance of the entire lens system, according to an embodiment of the present invention, the radius of curvature is 11 - 12 mm.

[0039] According to an embodiment of the present invention, the aspherical lens surface profile for each is:

[0040]

[0041] where x is the sagittal height of the lens surface profile, used to describe the height of each point on each aspherical surface in the optical axis direction; h is the aperture of the lens, used to describe the distance of each point on each aspherical surface perpendicular to the optical axis direction; c is the curvature of the vertex of each aspherical surface; k is the aspherical coefficient of each aspherical surface; Ai is the high-order aspherical coefficient of each aspherical surface, and i represents the power.

[0042] According to an embodiment of the present invention, D12 = 42.2, D3 = 74.9, Vd1 = 63.3, and Vd2 = 32.3.

[0043] Exemplarily, the focal length is set to 8.6 mm, the field of view angle is 175 degrees, and the diopter is 116 D. According to the above parameters and calculation formulas, the sizes of each lens obtained through simulation optimization are as shown in Table 1 and Table 2 below.

[0044] Table 1 Lens Size Table for Embodiment 1

[0045] Serial number Surface type R (Radius) value mm T Spacing thickness mm Refractive index d Abbe number V K value S1 Spherical surface -8.9 1 1.75 63.3 0 S2 Spherical surface -11.28 5 1.77 32.3 0 S3 Aspherical surface -7.77 0.2 - - -0.1 S4 Aspherical surface 23.6 6.27 1.68 37.2 -1.2 S5 Aspherical surface -12 - - - -2.5

[0046] Table 2 High-Order Aspherical Coefficient Table for Embodiment 1

[0047] Serial number A4 A6 A8 S3 3.03E-04 -1.03E-05 1.61E-07 S4 1.73E-05 -2.20E-09 1.20E-11 S5 -2.82E-05 3.02E-07 -4.72E-10

[0048] In addition, an optical evaluation was also performed on the constructed lens system according to the above design.

[0049] Figure 3 Shows the spherical aberration curve graph of the lens system. Among them, the abscissa is the spherical aberration values of different wavelengths, and the ordinate is the normalized entrance pupil diameter.

[0050] In addition, Figure 4 Shows the field curvature and distortion curves of the lens system. The abscissa of the left figure represents the distance from the center to the edge of the optical system, and the ordinate represents the value of the field curvature graph where the ordinate represents the deviation of the light ray from the chief ray on the image plane. The abscissa of the right figure is the distortion rate, and the Y-axis is the field of view angle.

[0051] The above has described the embodiments of the present invention. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art in this technical field to understand the embodiments disclosed herein.

Claims

1. A wide-angle imaging lens module for fundus retinal imaging, characterized in that: From left to right they include: A first lens having a first negative refractive power D1 and a first dispersion coefficient Vd1, wherein the left surface and the right surface of the first lens are both spherical surfaces; A second lens having a second positive refractive power D2 and a second dispersion coefficient Vd2, wherein the left surface of the second lens is a spherical surface and the right surface is an aspherical surface; A third lens having a third positive refractive power D3 and a second dispersion coefficient, wherein both the left and right surfaces of the second lens are aspherical surfaces; The first lens and the second lens are glued together and satisfy the following formula: 0.45≦D12 / D3≦0.65, 1.5≦Vd1 / Vd2≦2.5, Wherein, D12 is the combined optical power of the first lens and the second lens.

2. A wide-angle imaging lens module for fundus retinal imaging according to claim 1, characterized in that: The left surface of the first lens is a concave spherical surface so as to contact with the cornea of ​​the eyeball.

3. The wide-angle imaging lens module for fundus retinal imaging according to claim 2, characterized in that: The radius of curvature of the concave spherical surface is determined based on the size of the eyeball.

4. The wide-angle imaging lens module for fundus retinal imaging according to claim 3, characterized in that: The curvature radius is 7.5-9 mm.

5. The wide-angle imaging lens module for fundus retinal imaging according to claim 1, characterized in that: The first lens is made of a biocompatible light-transmitting material.

6. The wide-angle imaging lens module for fundus retinal imaging according to claim 5, characterized in that: Biocompatible light-transmitting materials include optical glass, quartz glass, and optical resin.

7. The wide-angle imaging lens module for fundus retinal imaging according to claim 1, characterized in that: The curvature radius of the right surface of the first lens is the same as the curvature radius of the left surface of the second lens.

8. The wide-angle imaging lens module for fundus retinal imaging according to claim 7, characterized in that: The radius of curvature is 11-12 mm.

9. The wide-angle imaging lens module for fundus retinal imaging according to claim 1, characterized in that: The lens surface shape of each aspherical surface is: Among them, x is the sag of the lens surface, which is used to describe the height of each point on each aspherical surface in the direction of the optical axis; h is the aperture of the lens, which is used to describe the distance perpendicular to the optical axis of each point on each aspherical surface; c is the curvature of the vertex of each aspherical surface; k is the aspherical coefficient of each aspherical surface; Ai is the high-order aspherical coefficient of each aspherical surface, and i represents the power.

10. The wide-angle imaging lens module for fundus retinal imaging according to claim 1, characterized in that: D12=42.2, D3=74.9, Vd1=63.3, and Vd2=32.3.

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