An optical system for imaging complex systems

Abstract

This invention proposes an optical system for imaging complex systems, comprising an eyepiece, an aperture stop, an aberration-correcting lens group, a front field lens group, a rear field lens group, and a prism group. The rear field lens group includes a semi-transparent, semi-reflective mirror. Light from the light source passes through the eyepiece and illuminates the pupil. Reflected light from the fundus exits the pupil and passes through the eyepiece, aperture stop, aberration-correcting lens group, front field lens group, and rear field lens group to reach the semi-transparent, semi-reflective mirror. 50% of the light passes through the semi-transparent, semi-reflective mirror into the prism group for RGB imaging, while the other 50% is reflected by the semi-transparent, semi-reflective mirror for white light imaging. The front field lens group includes a transmission-type deformable mirror. The focusing surfaces of the fundus, the aberration-correcting lens group, the front field lens group, and the prism group are conjugate. The pupil, the aperture stop, and the transmission-type deformable mirror are also conjugate. This invention ensures high precision, high stability, and high light energy utilization in complex imaging scenarios, providing a solution for multi-band, high-resolution diagnosis of fundus diseases.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic imaging equipment technology, and in particular to an optical system for imaging complex systems. Background Technology

[0002] In the field of medical imaging, fundus imaging technology has irreplaceable clinical value for the diagnosis of ophthalmic diseases, screening for diabetic retinopathy, and observation of ocular manifestations of systemic diseases. Traditional fundus imaging systems typically employ single-band illumination and fixed-focal-length optical designs, facing multiple technical challenges during the imaging process: 1. Limitations in aberration correction: Existing systems mostly use spherical lens combinations, which have limited ability to correct higher-order aberrations (such as spherical aberration, coma, and chromatic aberration), especially when observing the peripheral retinal region, easily causing image distortion and affecting diagnostic accuracy. 2. Limited focusing range: Conventional designs use fixed focal lengths, making it difficult to achieve rapid and accurate axial focusing compensation, and unable to adapt to the needs of different patients with varying pupil positions and lesion depths. 3. Lack of multi-band imaging: Traditional systems mostly use single white light illumination, unable to achieve simultaneous RGB multi-band imaging, limiting the ability to analyze lesion features (such as hemorrhages and exudates) in color vision. 4. Optical component coupling defects: Insufficient assembly precision of prism and lens groups easily generates stray light interference, and improper refractive index matching of prism materials leads to low light energy utilization. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide an optical system for imaging complex systems, ensuring high precision, high stability and high light energy utilization in complex imaging scenarios, and providing a solution for multi-band, high-resolution diagnosis of fundus diseases.

[0004] To achieve the above objectives, this invention proposes an optical system for imaging complex systems, comprising an eyepiece, an aperture stop, an aberration correction lens group, a front field lens group, a rear field lens group, and a prism group. The rear field lens group includes a semi-transparent mirror. Light from the light source passes through the eyepiece and illuminates the pupil. Reflected light from the fundus exits the pupil and sequentially passes through the eyepiece, aperture stop, aberration correction lens group, front field lens group, and rear field lens group before reaching the semi-transparent mirror. 50% of the light passes through the semi-transparent mirror and enters the prism group for RGB image processing. In this system, another 50% of the light is reflected by a semi-transparent mirror to form a white light image. The front field lens group includes a transmissive distorting mirror positioned parallel to the light rays. The rear field lens group includes a focusing compensation lens group positioned in front of the semi-transparent mirror and movable back and forth along the optical axis. The fundus position is conjugate to the focusing surface of the aberration correction lens group, the front field lens group, and the prism group. The pupil position is conjugate to the aperture stop position and the transmissive distorting mirror position.

[0005] In the above scheme: the aberration correction lens group consists of multiple lenses, which are arranged in order from the closest to the pupil to the furthest away from the pupil: a first positive lens, a second positive lens, a third positive lens, a fourth negative lens, a fifth positive lens, a sixth negative lens, and a first cemented lens.

[0006] In the above scheme: the aberration correction lens group is made of H-ZLAF90 with a refractive index of 1.9~2.0 and a dispersion coefficient of 23~24.

[0007] In the above scheme: the front field lens group consists of multiple lenses, which are arranged in order from the closest to the pupil to the furthest away from the pupil: a seventh positive lens, a second cemented lens, a transmission morphing lens, an eighth negative lens, and a ninth positive lens, wherein the eighth negative lens and the ninth positive lens are overlapped together.

[0008] In the above scheme: the rear field lens group consists of multiple lenses, which are arranged in order from the closest to the pupil to the furthest from the pupil: the third cemented lens, the tenth positive lens, the eleventh positive lens and the fourth cemented lens, wherein the third cemented lens and the tenth positive lens are combined to form a focusing compensation lens group.

[0009] In the above scheme: the semi-transparent and semi-reflective mirror is arranged between the focusing compensation lens group and the eleventh positive lens, and is arranged at a 45° angle with the optical axis direction. The twelfth positive lens and the fifth cemented lens are arranged in sequence on the reflected light path of the semi-transparent and semi-reflective mirror.

[0010] In the above scheme: the bottom of the focusing compensation lens group is equipped with a directional pulley or a directional guide rail to achieve back-and-forth movement along the optical axis.

[0011] In the above scheme: the prism group includes a first quadrangular prism, a triangular prism, and a second quadrangular prism. The refractive index of the first quadrangular prism is greater than 2.0, and the refractive indices of both the triangular prism and the second quadrangular prism are less than 1.5. The bottom surface of the triangular prism is glued to the top left side surface of the first quadrangular prism by applying adhesive at its four corners, with a gap of 0.1~0.2mm reserved between the two surfaces. The bottom surface of the second quadrangular prism is glued to the top right side surface of the triangular prism. The bottom surface and top right side surface of the first quadrangular prism, the top left side surface of the triangular prism, and the top surface of the second quadrangular prism are all coated with anti-reflective coatings. The top left side surface of the first quadrangular prism is coated with a light-filtering coating, the bottom surface of the triangular prism is coated with a reflective coating, and the glued surface formed by gluing the bottom surface of the second quadrangular prism to the top right side surface of the triangular prism is coated with a light-filtering coating.

[0012] RGB light is incident from the bottom surface of the first prism. R light is reflected from the top left surface of the first prism, then reflected from the bottom surface of the first prism to form a total internal reflection angle, and finally exits perpendicularly from the top right surface of the first prism to form an image. G light and B light both pass through the top left surface of the first prism and the bottom surface of the triangular prism. G light is reflected from the top right surface of the triangular prism, then reflected from the bottom surface of the triangular prism, and finally exits perpendicularly from the top left surface of the triangular prism to form an image. B light passes through the cemented surface formed by the bottom surface of the second prism and the top right surface of the triangular prism, and then exits perpendicularly from the top surface of the second prism to form an image.

[0013] In the above scheme: the material of the first quadrangular prism is HZLAF96, and the material of the triangular prism and the second quadrangular prism is HFK61.

[0014] In the above scheme, the eyepiece is an aspherical lens, which effectively reduces spherical aberration and improves the initial imaging quality.

[0015] The beneficial effects of this invention are:

[0016] 1. The aberration-correcting lens group reduces monochromatic aberrations such as spherical aberration through optical design, while the transmissive deformable lens of the front field lens group dynamically corrects wavefront distortions in the human eye (such as higher-order aberrations). Together, they achieve dual aberration compensation—"static + dynamic"—significantly improving the resolution and contrast of fundus images, making them particularly suitable for detecting early, minute lesions. 2. The fundus position is conjugate with the focusing surfaces of the aberration-correcting lens group, the front field lens group, and the prism group, ensuring image plane stability when all lens groups work together. The pupil position is conjugate with the aperture stop and deformable lens positions, allowing precise control of the beam aperture and field of view, reducing stray light interference, and improving the signal-to-noise ratio. 3. The system supports multi-wavelength light acquisition, enabling the acquisition of information from different layers of the fundus, facilitating in-depth disease diagnosis. 4. The focusing compensation lens group of the rear field lens group can move along the optical axis to adjust the system's focal length to match different patient fundus depths or focus on different layers of the retina, achieving "depth scanning" imaging and avoiding image blurring caused by defocusing.

[0017] In summary, through the coordinated design of the aberration correction lens group, the deformable lens, and the focus compensation lens group, combined with multi-segment light wave acquisition and conjugate optical path optimization, the system achieves high-resolution, low-distortion, and multimodal fundus imaging. This not only improves the diagnostic accuracy of early diseases, but also enhances the clinical practicality and ease of operation of the system through flexible focusing and patient-adaptive design. It is a typical innovative application of complex system imaging technology in ophthalmic diagnosis. Attached Figure Description

[0018] Figure 1 This is the optical path diagram of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged diagram of point A in the middle.

[0020] Figure 3 This is a schematic diagram of the prism assembly.

[0021] Figure 4 This is the MTF transfer function diagram of the present invention. Detailed Implementation

[0022] like Figure 1 As shown in Figure 4, an optical system for imaging complex systems mainly consists of an eyepiece 1, an aperture stop 2 (with a ring of light sources at the aperture stop 2), an aberration correction lens group 3, a front field lens group 4, a rear field lens group 5, and a prism group 6.

[0023] A semi-transparent mirror 7 is arranged in the rear field lens group 5. The light from the light source shines into the pupil through the eyepiece 1. The image of the fundus comes out from the pupil and passes through the eyepiece 1, aperture stop 2, aberration correction lens group 3, front field lens group 4, and rear field lens group 5 in sequence to reach the semi-transparent mirror 7. 50% of the light passes through the semi-transparent mirror 7 and enters the prism group 6 for RGB imaging, while the other 50% of the light is reflected by the semi-transparent mirror 7 for white light imaging.

[0024] Eyepiece 1 is an aspherical lens, which effectively reduces spherical aberration and improves the initial image quality.

[0025] The front field lens group 4 includes a transmissive distorting lens 8, which is positioned parallel to the light rays. The rear field lens group 5 includes a focusing compensation lens group 51, which is positioned in front of the semi-transparent mirror 7 and can move back and forth along the optical axis. The fundus position is conjugate to the focusing plane of the aberration correction lens group 3, the front field lens group 4, and the focusing plane of the prism group 6. The pupil position is conjugate to the position of the aperture stop 2 and the position of the transmissive distorting lens 8.

[0026] Specifically, the aberration correction lens group 3 consists of multiple lenses, which are arranged from closest to the pupil to furthest from the pupil as follows: first positive lens, second positive lens, third positive lens, fourth negative lens, fifth positive lens, sixth negative lens, and first cemented lens.

[0027] Specifically, the aberration-correcting lens group 3 is made of H-ZLAF90 with a refractive index of 1.9~2.0 and a dispersion coefficient of 23~24.

[0028] Specifically, the front field lens group 4 consists of multiple lenses, which are arranged from the closest to the pupil to the furthest away from the pupil as the seventh positive lens, the second cemented lens, the transmission morphing lens 8, the eighth negative lens, and the ninth positive lens. The eighth negative lens and the ninth positive lens are overlapped together (overlapping together means that the maximum gap between the two corresponding lenses is less than 0.5mm, and there is an overlap between them).

[0029] Specifically, the rear field lens group 5 consists of multiple lenses, which are arranged from closest to the pupil to furthest from the pupil as the third cemented lens, the tenth positive lens, the eleventh positive lens and the fourth cemented lens. The third cemented lens and the tenth positive lens are combined to form the focusing compensation lens group 51.

[0030] Specifically, the semi-transparent mirror 7 is positioned between the focusing compensation lens group 51 and the eleventh positive lens, and is arranged at a 45° angle to the optical axis. The twelfth positive lens and the fifth cemented lens (imaging lens group, connected to CCD) are sequentially arranged in the reflected light path of the semi-transparent mirror 7.

[0031] Specifically, the bottom of the focusing compensation lens group 51 is equipped with a directional pulley or a directional guide rail to enable back-and-forth movement along the optical axis.

[0032] Specifically, the prism assembly 6 includes a first quadrangular prism 61, a triangular prism 62, and a second quadrangular prism 63. The refractive index of the first quadrangular prism 61 is greater than 2.0, while the refractive indices of the triangular prism 62 and the second quadrangular prism 63 are both less than 1.5. The bottom surface of the triangular prism 62 is glued to the left top surface of the first quadrangular prism 61 by applying adhesive at its four corners, with a gap of 0.1~0.2mm reserved between the two surfaces. The bottom surface of the second quadrangular prism 63 is glued to the right top surface of the triangular prism 62. The bottom surface and right top surface of the first quadrangular prism 61, the left top surface of the triangular prism 62, and the top surface of the second quadrangular prism 63 are all coated with anti-reflective coatings. The left top surface of the first quadrangular prism 61 is coated with a filter film, the bottom surface of the triangular prism 62 is coated with a reflective film, and the glued surface formed by gluing the bottom surface of the second quadrangular prism 63 to the right top surface of the triangular prism 62 is coated with a filter film.

[0033] The first quadrangular prism 61 is made of HZLAF96, while the triangular prism 62 and the second quadrangular prism 63 are made of HFK61.

[0034] RGB light (including R, G, and B light) is incident from the bottom surface of the first quadrangular prism 61. R light is reflected from the top left surface of the first quadrangular prism 61, then reflected from the bottom surface of the first quadrangular prism 61 to form a total internal reflection angle, and finally exits perpendicularly from the top right surface of the first quadrangular prism 61 to form an image. G light and B light both pass through the top left surface of the first quadrangular prism 61 and the bottom surface of the triangular prism 62. G light is reflected from the top right surface of the triangular prism 62, then reflected from the bottom surface of the triangular prism 62, and finally exits perpendicularly from the top left surface of the triangular prism 62 to form an image. B light passes through the cemented surface formed by the bottom surface of the second quadrangular prism 63 and the top right surface of the triangular prism 62, and then exits perpendicularly from the top surface of the second quadrangular prism 63 to form an image.

Claims

1. An optical system for imaging complex systems, comprising an eyepiece (1), an aperture stop (2), and an aberration correction lens group (3), characterized in that: It also includes a front field mirror group (4), a rear field mirror group (5), and a prism group (6). A semi-transparent mirror (7) is arranged in the rear field mirror group (5). The light from the light source shines into the pupil through the eyepiece (1). The reflected light from the fundus comes out from the pupil and passes through the eyepiece (1), the aperture stop (2), the aberration aberration mirror group (3), the front field mirror group (4), and the rear field mirror group (5) in sequence to reach the semi-transparent mirror (7). 50% of the light passes through the semi-transparent mirror (7) and enters the prism group (6) for RGB imaging, while the other 50% of the light is reflected by the semi-transparent mirror (7) for white imaging. In optical imaging, the front field lens group (4) includes a transmissive deformable lens (8), which is positioned parallel to the light rays. The rear field lens group (5) includes a focusing compensation lens group (51), which is positioned in front of the semi-transparent mirror (7) and can move back and forth along the optical axis. The position of the fundus is conjugate to the focusing surface of the aberration-correcting lens group (3), the focusing surface of the front field lens group (4), and the focusing surface of the prism group (6). The position of the pupil is conjugate to the position of the aperture stop (2) and the position of the transmissive deformable lens (8). The aberration correction lens group (3) consists of multiple lenses, arranged from closest to the pupil to furthest from the pupil as a first positive lens, a second positive lens, a third positive lens, a fourth negative lens, a fifth positive lens, a sixth negative lens, and a first cemented lens; the front field lens group (4) consists of multiple lenses, arranged from closest to the pupil to furthest from the pupil as a seventh positive lens, a second cemented lens, a transmission morphing lens (8), an eighth negative lens, and a ninth positive lens, wherein the eighth negative lens and the ninth positive lens are overlapped; the rear field lens group (5) consists of multiple lenses... The lens assembly consists of a third cemented lens, a tenth positive lens, an eleventh positive lens, and a fourth cemented lens, arranged sequentially from closest to the pupil to furthest from the pupil. The third cemented lens and the tenth positive lens are combined to form a focusing compensation lens group (51). The bottom of the focusing compensation lens group (51) is equipped with a directional pulley or a directional guide rail to enable back-and-forth movement along the optical axis. The prism group (6) includes a first quadrangular prism (61), a triangular prism (62), and a second quadrangular prism (63). The refractive index of the first quadrangular prism (61) is greater than 2.

0. The refractive indices of both the triangular prism (62) and the second quadrangular prism (63) are less than 1.

5. The bottom surface of the triangular prism (62) is glued to the top left side of the first quadrangular prism (61) by applying adhesive at the four corners, with a gap of 0.1~0.2mm reserved between the two surfaces. The bottom surface of the second quadrangular prism (63) is glued to the top right side of the triangular prism (62). The bottom surface and top right side of the first quadrangular prism (61), the top left side of the triangular prism (62), and the top right side of the second quadrangular prism (63) are all connected. 3) The top surface of each of the mirrors is coated with an anti-reflective coating. The top left surface of the first prism (61) is coated with a filter film, the bottom surface of the triangular prism (62) is coated with a reflective film, and the glued surface formed by the glued bottom surface of the second prism (63) and the top right surface of the triangular prism (62) is coated with a filter film. The semi-transparent and semi-reflective mirror (7) is arranged between the focusing compensation mirror group (51) and the eleventh positive lens, and is arranged at a 45° angle with the optical axis. The twelfth positive lens and the fifth glued mirror are arranged in sequence on the reflected light path of the semi-transparent and semi-reflective mirror (7).

2. The optical system for imaging complex systems according to claim 1, characterized in that: The aberration-correcting lens group (3) is made of H-ZLAF90 with a refractive index of 1.9~2.0 and a dispersion coefficient of 23~24.

3. The optical system for imaging complex systems according to claim 1, characterized in that: The first quadrangular prism (61) is made of HZLAF96, and the triangular prism (62) and the second quadrangular prism (63) are made of HFK61.

4. The optical system for imaging complex systems according to claim 1, characterized in that: The eyepiece (1) is an aspherical lens.

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