Optical system for fundus imaging

Abstract

The application provides an optical system for fundus imaging of an eye to be tested, comprising: a fundus illumination light path for providing a light source to illuminate the fundus of the eye to be tested; a fundus imaging light path comprising an accommodating lens for fundus imaging of the eye to be tested; a fixation light path for providing a fixation target to enable the eye to be tested to fixate; and an auxiliary accommodating light path, the auxiliary accommodating light path sharing the accommodating lens with the fundus imaging light path to improve the accuracy and reliability of the accommodation. By sharing the accommodating lens between the auxiliary accommodating light path and the fundus imaging light path, the complicated linkage adjusting mechanism is avoided, the accuracy and reliability of the accommodation alignment are improved, the device cost is saved, and the purposes of economy, high efficiency, accuracy and convenience are achieved. Further, the fundus imaging of the eye to be tested is realized by combining the iris split imaging and the fundus illumination technology, and whether the accommodation imaging light path of the fundus imaging optical system is adjusted to the clearest according to the refractive power of different eyes to be tested is objectively evaluated, so that the clearest fundus color photograph is obtained.

Description

Technical Field

[0001] This invention relates to the field of fundus imaging technology, and more particularly to a fundus imaging optical system. Background Technology

[0002] Fundus cameras belong to the field of medical imaging and are used to acquire images of the human retina, enabling medical personnel to examine fundus diseases or assist in assessing the condition of other organs. Since the blood vessels in the fundus are the only blood vessels in the human body that can be directly observed through the body surface, medical personnel can use fundus cameras to examine the optic nerve, retina, choroid, and refractive media for lesions. Furthermore, fundus cameras can assist in the diagnosis and assessment of other systemic diseases, such as screening retinal images for cerebral infarction, cerebral hemorrhage, cerebral arteriosclerosis, brain tumors, diabetes, kidney disease, hypertension, retinopathy of prematurity, glaucoma, and age-related macular degeneration. The earlier these diseases are detected, the better for clinical treatment; therefore, fundus cameras are widely used in clinical screening for fundus diseases and have become an indispensable medical device.

[0003] The existing patent, "An Auxiliary Adjustment Optical Path for Imaging Optical Path in a Fundus Camera, Application No. 201420600579.0," adds an auxiliary adjustment optical path to the illumination optical path. This requires introducing an additional linkage adjustment mechanism to ensure synchronous refractive adjustment in the imaging optical path. This linkage adjustment mechanism, whether by adding an extra motion motor or employing a dedicated linkage motion mechanism, will increase system complexity and cost. Furthermore, the linkage mechanism will introduce additional errors to the accuracy of synchronous adjustment, preventing the optimal adjustment effect from being achieved.

[0004] Furthermore, during fundus imaging, the optical system needs to be adjusted to improve its imaging path based on the refractive power of the tested eye, resulting in a clearer fundus image. During this adjustment, the surgeon typically uses the infrared preview image of the tested eye to guide the imaging process. When taking the photograph, the optical system instantly switches to flash mode to obtain a color image of the fundus. However, the infrared preview illumination source has relatively weak light energy. Excessive light can cause the pupil to constrict, affecting the image capture. The weak infrared preview light source also leads to misjudgment when judging the clarity of the fundus image based on a blurry preview, resulting in an inability to obtain the clearest fundus image during flash photography.

[0005] In the existing technology, there is a lack of an efficient and economical method for assisted tilting imaging, as well as a convenient and objective method for evaluating whether the tilting imaging optical path is the clearest.

[0006] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] In order to solve the existing problems, the present invention provides a fundus imaging optical system.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] An optical system for fundus imaging of a test eye includes: a fundus illumination optical path for providing a light source to illuminate the fundus of the test eye; a fundus imaging optical path including an adjustment lens for imaging the fundus of the test eye; a fixation optical path for providing a fixation target to enable the test eye to fixate; and an auxiliary adjustment optical path, wherein the auxiliary adjustment optical path shares the adjustment lens with the fundus imaging optical path to improve the accuracy and reliability of adjustment.

[0010] Preferably, the fundus illumination optical path includes an illumination output optical path, an aperture reflector, and an eyepiece objective lens; the light emitted from the light source in the fundus illumination optical path is reflected by the aperture reflector and then transmitted through the eyepiece objective lens to illuminate the fundus of the tested eye; wherein, the aperture reflector has a first through hole in the middle, and the annular illumination light formed by the fundus illumination optical path is reflected by the reflector portion of the aperture reflector other than the first through hole.

[0011] Preferably, a first aperture is provided in the first through hole; the fundus imaging optical path further includes the eyepiece objective, the first aperture, an imaging mirror, a beam splitter, and a camera device; the light emitted from the fundus passes through the eyepiece objective, through the first aperture, and is then adjusted in diopter by the adjusting mirror, and then passes through the imaging mirror and the beam splitter, finally being imaged onto the camera device; wherein, the beam splitter allows the light emitted from the illumination light path to pass through the beam splitter to reach the camera device.

[0012] Preferably, the fixation optical path includes the eyepiece objective, the first aperture, the adjusting lens, the imaging lens, the beam splitter, the fixed-beam splitter, and the fixation light source; light from the fixation light source is reflected by the fixed-beam splitter and the beam splitter, transmitted through the imaging lens and the adjusting lens, passes through the first aperture, passes through the eyepiece objective, and then enters the tested eye, whereby the internal fixation target is projected onto the fundus of the tested eye; wherein, the fixation light source and the imaging device are arranged conjugately relative to the beam splitter.

[0013] Preferably, the auxiliary refractive optical path includes the eyepiece objective, the first aperture, the refractive mirror, the imaging mirror, the beam splitter, the fixed refractive beam splitter, the refractive beam splitter, the refractive receiving aperture, the refractive detector, the refractive source, and the refractive output aperture; wherein, the light emitted from the refractive source passes through the refractive output aperture, is partially reflected by the refractive beam splitter, transmits through the fixed refractive beam splitter, is reflected again by the beam splitter, passes through the imaging mirror and the refractive mirror, passes through the first aperture, passes through the eyepiece objective, and then enters the target optical path. The light beam is projected onto the fundus of the tested eye. After being scattered or reflected by the fundus of the tested eye, the light beam returns along the original optical path to the adjusting beam splitter, partially transmits through the adjusting beam splitter, passes through the adjusting receiving aperture, and is finally received by the adjusting detector. The adjusting beam splitter partially transmits and partially reflects the light emitted from the adjusting light source. The adjusting output aperture and the adjusting receiving aperture are conjugate with respect to the adjusting beam splitter. The adjusting receiving aperture and the fixed light source are conjugate with respect to the fixed beam splitter.

[0014] Preferably, the auxiliary refractive optical path includes an auxiliary refractive light source, a pinhole aperture, a first lens for the auxiliary refractive optical path, a double-aperture aperture, a second lens for the auxiliary refractive optical path, the fixed-beam splitter, the eyepiece objective, the first aperture, the refractive mirror, the imaging mirror, the beam splitter, and the imaging device; wherein, the light emitted from the auxiliary refractive light source passes through the pinhole aperture, and then through the first lens and the double-aperture aperture, becomes two independent fine beams; the two fine beams converge at the convergence point on the principal optical axis of the auxiliary refractive optical path after passing through the second lens; the two fine beams separate again, are transmitted through the fixed-beam splitter, reflected by the beam splitter, pass through the imaging lens and the refractive mirror, and then pass through the opening of the first aperture, and the two beams... The two fine beams are refocused on the conjugate image plane of the fundus of the tested eye; the two fine beams separate again, pass through the eyepiece objective, enter the pupil of the tested eye, and finally refocus on the fundus of the tested eye; the fundus of the tested eye scatters the beams to obtain two scattered beams, which exit the tested eye, pass through the eyepiece objective, the first aperture, the adjusting lens, the imaging lens, and the beam splitter, and finally converge on the imaging device; wherein, the conjugate image plane is the imaging plane of the fundus of the tested eye formed by the eyepiece objective; the convergence point on the principal optical axis of the auxiliary adjusting optical path is conjugate to the center point of the imaging device relative to the beam splitter; the center point of the fixed light source is conjugate to the convergence point on the principal optical axis of the auxiliary adjusting optical path relative to the fixed beam splitter.

[0015] Preferably, the fundus illumination optical path includes an illumination light source, an illumination light filter, and an eyepiece objective; wherein, the illumination light source emits light, which is transmitted through the illumination light filter and the eyepiece objective to illuminate the fundus of the tested eye; wherein, the illumination light filter has a second through-hole in the middle, and a second aperture is disposed within the second through-hole; the illumination light source is symmetrically distributed relative to the second aperture; the fundus imaging optical path further includes the eyepiece objective, the second aperture, an imaging filter, an imaging mirror, a beam splitter, and an imaging device.

[0016] Preferably, the auxiliary adjustment optical path includes the eyepiece objective, the second aperture, an imaging filter, an adjustment mirror, an imaging mirror, a beam splitter, a fixed-beam splitter, an adjustment beam splitter, an adjustment receiving aperture, an adjustment detector, an adjustment source, and an adjustment output aperture; wherein, the light emitted from the adjustment source passes through the adjustment output aperture, is partially reflected by the adjustment beam splitter, transmits through the fixed-beam splitter, is reflected again by the beam splitter, passes through the imaging mirror, the adjustment mirror, the imaging filter, and the second aperture. The beam passes through the eyepiece objective lens and then into the tested eye, finally projecting onto the fundus of the tested eye. After being scattered or reflected by the fundus of the tested eye, the beam returns along the original optical path to the adjusting beam splitter, partially transmits through the adjusting beam splitter, passes through the adjusting receiving aperture, and is finally received by the adjusting detector. The adjusting output aperture and the adjusting receiving aperture are arranged conjugately relative to the adjusting beam splitter. The adjusting receiving aperture and the fixed light source are arranged conjugately relative to the fixed beam splitter.

[0017] Preferably, the fundus imaging optical system further includes an iris split-image imaging optical path, which includes an iris illumination source and two iris split-image imaging sub-paths, which are respectively disposed on the left and right sides of the eyepiece objective lens; each of the iris split-image imaging sub-paths includes an iris filter, an iris imaging lens, and an iris imaging device; wherein, the light emitted by the iris illumination source illuminates the anterior chamber of the tested eye, the light is reflected by the anterior chamber tissue, the reflected light passes through the iris filter and the iris imaging lens, and is finally captured by the iris imaging device.

[0018] Preferably, the working position of the tested eye is determined by intersecting the main optical axis of the two sub-optical paths with the main optical axis of the probe optical path; or, the two sub-optical paths obtain the upper and lower anterior chamber images of the tested eye through imaging, and the working distance is determined by stitching together the images of the upper and lower anterior chamber images.

[0019] The beneficial effects of this invention are as follows: It provides a fundus imaging optical system in which the auxiliary adjustment optical path and the fundus imaging optical path share the same adjustment lens, which not only eliminates the need for a complex linkage adjustment mechanism and improves the accuracy and reliability of adjustment alignment, but also saves on device costs and achieves the goals of economy, efficiency, precision and convenience.

[0020] Furthermore, by combining iris split-image imaging and fundus illumination technology, fundus imaging of the tested eye is achieved, and the refractive imaging optical path of the fundus imaging optical system is objectively evaluated to ensure that it is adjusted to the clearest value according to the different refractive powers of the tested eye, thereby obtaining the clearest fundus color image. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the probe of the fundus imaging optical system in Embodiment 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of the distribution of the optical path for iris split imaging in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the probe of the fundus imaging optical system in Embodiment 2 of the present invention.

[0024] Figure 4 This is a schematic diagram of the probe of the fundus imaging optical system in Embodiment 3 of the present invention.

[0025] Figure 5 This is a schematic diagram illustrating the principle of the auxiliary adjustment imaging optical path in Embodiment 3 of the present invention.

[0026] Among them, 10-first probe, 20-second probe, 30-third probe, L1-main optical axis, 140-illumination output optical path, 1401-aperture mirror, 1201-eyepiece objective lens, 1203-first aperture / second aperture, 1204-adjustment mirror, 1205-imaging mirror, 1206-beam splitter, 1207-camera device, 1301-adjustment detector, 1303-adjustment receiving aperture, 1305-adjustment beam splitter, 1311-adjustment light source, 1313-adjustment output aperture, 1701-fixed light source, 1703-fixed beam splitter, 1901L-first iris illumination light source, 1901R-second iris illumination light source, 1 805L - First iris filter, 1805R - Second iris filter, 1803L - First iris imaging lens, 1803R - Second iris imaging lens, 1801L - First iris imaging device, 1801R - Second iris imaging device, L18L - Main optical axis of the first sub-optical path, L18R - Main optical axis of the second sub-optical path, 2401 - Illumination light source, 2403 - Illumination light source filter, 2211 - Imaging filter, 3301 - Auxiliary refractive light source, 3303 - Pinhole aperture, 3304 - First lens of auxiliary refractive optical path, 3305 - Double aperture aperture, 3306 - Second lens of auxiliary refractive optical path, E - Test eye, Er - Fundus. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0028] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] This invention provides a fundus imaging optical system for performing fundus imaging on a tested eye, comprising:

[0032] The fundus illumination light path is used to provide a light source to illuminate the fundus of the eye being tested;

[0033] The fundus imaging optical path includes an adjustable lens, used to perform fundus imaging on the tested eye;

[0034] A fixation optical path for providing a fixation target to enable the tested eye to fixate; and

[0035] An auxiliary refractive optical path is provided, which shares a refractive lens with the fundus imaging optical path to improve the accuracy and reliability of refractive adjustment.

[0036] This invention uses a diopter adjustment lens that shares the auxiliary diopter adjustment optical path with the fundus imaging optical path. This not only eliminates the need for a complex linkage adjustment mechanism and improves the accuracy and reliability of diopter adjustment alignment, but also saves on device costs, achieving the goals of economy, efficiency, precision and convenience.

[0037] The fundus imaging optical system provided by this invention can achieve refractive-assisted accommodation of the tested eye through the confocal adjustment principle; it uses a common imaging optical path adjustment lens to achieve simultaneous adjustment of the auxiliary adjustment optical path, fixation optical path, and imaging optical path; this confocal auxiliary adjustment optical path principle is not limited or affected by the illumination optical path scheme. It can be used for fundus imaging of the tested eye whether the instrument is operated manually or in a fully automatic manner.

[0038] The following is a detailed explanation.

[0039] Example 1

[0040] like Figure 1 As shown in the diagram, the lens is merely an illustration and can be constructed as a laminated component or lens assembly, which is common knowledge. The first probe 10 of the fundus imaging optical system includes: a fundus illumination optical path, a fundus imaging optical path, a fixation optical path, and an auxiliary refractive optical path; these are described below:

[0041] 1. Fundus illumination optical path

[0042] The fundus illumination optical path is used to provide ring illumination of the fundus using infrared light and white light flash, so that the fundus imaging optical path can realize infrared preview imaging and flash photography of the fundus.

[0043] The fundus illumination optical path includes an illumination output light path 140, an aperture reflector 1401, and an eyepiece objective lens 1201. Light emitted from a light source (not shown) in the fundus illumination optical path is reflected by the aperture reflector 1401, then transmitted through the eyepiece objective lens 1201, and finally passes through the tested eye E to illuminate the fundus Er of the tested eye. The aperture reflector 1401 has a through-hole in its center, and a first aperture 1203 is disposed within the first through-hole. The annular illumination light generated by the fundus illumination optical path is reflected by the portion of the reflector outside the through-hole of the aperture reflector 1401.

[0044] 2. Fundus imaging optical path

[0045] The fundus imaging optical path includes an eyepiece objective lens 1201, a first aperture 1203, a diopter lens 1204, an imaging lens 1205, a beam splitter 1206, and a camera device 1207. This fundus imaging optical path is used to achieve infrared preview and white light flash imaging of the fundus.

[0046] The light emitted from the fundus Er passes through the tested eye E, the eyepiece objective lens 1201, the first aperture 1203, and is then adjusted in diopter by the diopter lens 1204. The light then passes through the imaging lens 1205 and the beam splitter 1206, and is finally imaged onto the camera device 1207.

[0047] The beam splitter 1206 allows infrared and white light emitted from the illumination light path 140 to be transmitted through the beam splitter 1206 to the imaging device 1207, thereby obtaining an infrared preview image of the fundus or a color photograph of the fundus. Meanwhile, the light emitted from the fixation light source 1701 and the adjustment light source 1311 is reflected by the beam splitter 1206.

[0048] Furthermore, the movement of the adjusting lens 1204 allows the fundus Er of different tested eyes to be adjusted to conjugate with the imaging device 1207, thereby obtaining a clear image of the fundus.

[0049] When taking a picture, another preferred method is to quickly switch the beam splitter 1206 away from the imaging optical path using a shutter device (not shown).

[0050] 3. Fix the light path

[0051] The fixation light source 1701 in the fixation optical path is used for the fixation target (internal fixation target) of the tested eye E. The fixation optical path includes an eyepiece objective lens 1201, a first aperture 1203, an adjusting lens 1204, an imaging lens 1205, a beam splitter 1206, a fixation beam splitter 1703, and a fixation light source 1701.

[0052] Light from the fixation light source 1701 is reflected by the fixation beam splitter 1703 and the beam splitter 1206, transmitted through the imaging mirror 1205 and the adjusting mirror 1204, and passes through the first aperture 1203. This light then passes through the eyepiece objective lens 1201 and enters the tested eye E. Finally, the internal fixation target is projected onto the fundus Er of the tested eye E. The fixation light source 1701 and the imaging device 1207 are arranged conjugately with respect to the beam splitter 1206. Therefore, when the adjusting mirror 1204 adjusts, it ensures that when the fixation target is clearly seen by the tested eye E, the imaging device 1207 can simultaneously obtain a clear image of the fundus Er.

[0053] The fixed-view light source 1701 can be a single-point LED, or an LCD screen, OLED screen, or LED array screen, etc. The fixed-view beam splitter 1703 can transmit the light emitted from the fixed-view light source 1311 and reflect the light from the fixed-view light source 1701.

[0054] 4. Assist in adjusting the refractive path

[0055] The auxiliary diopter optical path includes an eyepiece objective lens 1201, a first aperture 1203, a diopter lens 1204, an imaging lens 1205, a beam splitter 1206, a fixed diopter beam splitter 1703, a diopter beam splitter 1305, a diopter receiving aperture 1303, a diopter detector 1301, a diopter light source 1311, and a diopter output aperture 1313.

[0056] The light emitted from the adjustable light source 1311 passes through the adjustable light output aperture 1313, is partially reflected by the adjustable beam splitter 1305, transmits through the fixed beam splitter 1703, is reflected again by the beam splitter 1206, passes through the imaging mirror 1205 and the adjustable mirror 1204, passes through the first aperture 1203, and then enters the tested eye E through the eyepiece objective lens 1201, finally projecting onto the fundus Er of the tested eye E. After being scattered or reflected by the fundus Er, the light beam returns along the original optical path to the adjustable beam splitter 1305, is partially transmitted through the adjustable beam splitter 1305, passes through the adjustable receiving aperture 1303, and is finally received by the adjustable detector 1301. The adjustable beam splitter 1305 can partially transmit and partially reflect the light emitted from the adjustable light source 1311.

[0057] The adjusting output aperture 1313 and the adjusting receiving aperture 1303 are arranged conjugately relative to the adjusting beam splitter 1305. The adjusting receiving aperture 1303 and the fixed light source 1701 are arranged conjugately relative to the fixed beam splitter 1703.

[0058] Because the refractive power of the tested eye E is different, the light emitted from the adjusting light source 1311 after passing through the adjusting light output aperture 1313 will form a diffuse spot when projected onto the fundus Er if the refractive power is not properly adjusted. The light reflected back from the fundus Er will also form a diffuse spot at the adjusting receiving aperture 1303. In this case, most of this diffuse spot will be blocked by the adjusting receiving aperture 1303 and will not reach the adjusting detector 1301, resulting in a very weak light signal received by the adjusting detector 1301. Only when the adjusting lens 1204 is properly adjusted will the adjusting light output aperture 1313 be conjugate with the fundus Er. At this time, the light reflected from the fundus Er can be focused onto the adjusting receiving aperture 1303, pass through the adjusting receiving aperture 1303, and be received by the adjusting detector 1301. The light signal received by the adjusting detector 1301 will then be the strongest. Therefore, the strength of the light signal received by the diopter detector 1301 can determine whether the diopter of the diopter lens 1204 is properly adjusted.

[0059] The system of the present invention utilizes an auxiliary adjustment optical path to achieve precise adjustment of the adjustment lens 1204, thereby simultaneously ensuring that when the light signal received by the adjustment detector 1301 is at its strongest, the fixed target is clearly seen by the tested eye E, and the imaging device 1207 obtains a clear image of the fundus Er.

[0060] In one embodiment of the present invention, the fundus imaging optical system further includes an iris split-image imaging optical path.

[0061] Combination Figure 1 and Figure 2 As shown, the fundus imaging optical system also includes an iris split-image imaging optical path, which includes an iris illumination source 1901 and two iris split-image imaging sub-paths. The iris split-image imaging sub-paths are respectively arranged on the left and right sides of the eyepiece objective. Each of the iris split-image imaging sub-paths includes an iris filter, an iris imaging lens, and an iris imaging device. The iris illumination source 1901 is schematically shown as a dual iris illumination source 1901L and 1901R, but the iris illumination source 1901 can also be a single light source, such as distributed below the eyepiece objective 1201, or multiple light sources can be used to illuminate the periphery of the eyepiece objective 1201.

[0062] In one specific embodiment, the first iris filter 1805L, the first iris imaging lens 1803L, and the first iris camera device 1801L constitute a first sub-optical path, and the second iris filter 1805R, the second iris imaging lens 1803R, and the second iris camera device 1801R constitute a second sub-optical path.

[0063] When the iris split-image imaging optical path is working, the light emitted by the iris illumination source 1901 (infrared light) illuminates the anterior chamber of the tested eye E, and the light is reflected by the anterior chamber tissue. The reflected light passes through the iris filter 1805 and the iris imaging lens 1803, and is finally captured by the iris camera device 1801.

[0064] The optical path for the iris split-image imaging sub-path is preferably distributed on the left and right sides of the eyepiece objective 1201. If it is distributed vertically relative to the first probe 10, it is easily obstructed by the eyelid, which is not conducive to the realization of the iris split image. The iris illumination source 1901 can be composed of one or more light sources, and its distribution can be as shown in the figure above, either on the left and right sides of the eyepiece objective 1201, or vertically, or in an array.

[0065] Because the two iris split-image imaging sub-paths are symmetrically distributed on both sides, the principal optical axis of the first sub-path is L18L, and the principal optical axis of the second sub-path is L18R, which intersects with the principal optical axis of the probe optical path at L1. Similar to the principle of binocular distance measurement, the working position of the tested eye can be determined through the two iris split-image imaging sub-paths. Alternatively, the two iris split-image imaging sub-paths can be used to obtain the upper and lower parts of the anterior chamber image of the tested eye E through imaging. The working distance can be determined by stitching the images of the upper and lower parts of the anterior chamber image. When the images of the upper and lower parts of the anterior chamber image can be stitched together to form a complete iris image or pupil image, the tested eye can be determined to be in the required working position.

[0066] When the tested eye E deviates vertically from the working position, the pupil or iris image will be deviated from one side of the image of the anterior chamber in the upper and lower parts of the image, so that the pupil or iris is not symmetrically distributed vertically along the image of the anterior chamber in the upper and lower parts of the image.

[0067] When the eye measurement E deviates from the working position to the left or right, the pupil or iris image in the upper and lower parts of the anterior chamber image will deviate from the center of the image in the same direction.

[0068] When the eye measurement E deviates from the working position, the pupil or iris image in the upper and lower parts of the anterior chamber image will deviate in opposite directions, making it impossible to stitch the pupil or iris images together.

[0069] The above determination method can be used to assist the first probe 10 in three-dimensional adjustment in the up, down, left, right, and front and back directions through two sub-optical paths, so that the tested eye E is in the working position required for fundus imaging.

[0070] The first probe 10 determines the position of the tested eye E according to the iris split-image imaging optical path, and moves the tested eye to the working position required for fundus imaging by three-dimensionally moving the first probe 10; at the same time, it uses the auxiliary adjustment optical path to guide the adjustment lens 1204 to adjust precisely.

[0071] Once the above conditions are met, the fundus imaging optical system can drive the illumination output light path 140 to flash white light, while the camera device 1207 takes a picture simultaneously, thereby obtaining a clear color photo of the fundus of the tested eye E.

[0072] Example 2

[0073] like Figure 3 As shown, probe 20 also includes: a fundus illumination optical path, a fundus imaging optical path, a fixation optical path, an auxiliary refractive optical path, and an iris split-image imaging optical path. The following details only the parts that differ from those in Example 1; other parts are described in the same way as in Example 1.

[0074] 1. Fundus illumination optical path

[0075] The fundus illumination optical path includes an illumination light source 2401, an illumination light-emitting filter 2403, and an eyepiece objective lens 1201. Light emitted from the illumination light source 2401 passes through the transmission illumination light-emitting filter 2403 and the eyepiece objective lens 1201, and then through the human eye (E) to illuminate the fundus (Er). The illumination light-emitting filter 2403 has a second through-hole in its center, within which a second aperture 1203 is disposed. The illumination light source 2401 is symmetrically distributed relative to the second aperture 1203 and can consist of one or more light sources, capable of emitting infrared illumination light or white flashes. The illumination light-emitting filter 2403 serves to filter or alter the polarization state of the illumination light.

[0076] 2. Fundus imaging optical path

[0077] The fundus imaging optical path includes an eyepiece objective lens 1201, a second aperture 1203, an imaging filter 2211, a diopter lens 1204, an imaging lens 1205, a beam splitter 1206, and a camera device 1207. The fundus imaging optical path is used to achieve infrared preview and white light flash imaging of the fundus.

[0078] Light emitted from the fundus (Er) passes through the human eye (E), the eyepiece objective lens 1201, the second aperture 1203, and the imaging filter 2211. Its diopter is then adjusted by the adjusting lens 1204. The light then passes through the imaging mirror 1205 and the beam splitter 1206, finally forming an image on the imaging device 1207. The imaging filter 2211 serves to filter light or change the polarization state of the illuminating light.

[0079] 3. Fix the light path

[0080] The fixed optical path includes an eyepiece objective lens 1201, a second aperture 1203, an imaging filter 2211, a diopter lens 1204, an imaging lens 1205, a beam splitter 1206, a fixed diopter beam splitter 1703, and a fixed light source 1701.

[0081] Light from the fixation light source 1701 is reflected by the fixation beam splitter 1703 and the beam splitter 1206, transmitted through the imaging mirror 1205 and the adjustment mirror 1204, and passes through the imaging filter 2211 and the second aperture 1203. The light then passes through the eyepiece objective lens 1201 and enters the tested eye E. Finally, the internal fixation target is projected onto the fundus Er of the tested eye E.

[0082] 4. Assist in adjusting the refractive path

[0083] The auxiliary diopter optical path includes an eyepiece objective lens 1201, a second aperture 1203, an imaging filter 2211, a diopter lens 1204, an imaging lens 1205, a beam splitter 1206, a fixed diopter beam splitter 1703, a diopter beam splitter 1305, a diopter receiving aperture 1303, a diopter detector 1301, a diopter light source 1311, and a diopter output aperture 1313.

[0084] The light emitted from the adjustable light source 1311 passes through the adjustable light output aperture 1313, is partially reflected by the adjustable beam splitter 1305, is transmitted through the fixed beam splitter 1703, is reflected again by the beam splitter 1206, passes through the imaging mirror 1205 and the adjustable mirror 1204, passes through the imaging filter 2211 and the second aperture 1203, and then enters the tested eye E through the eyepiece objective lens 1201, and is finally projected onto the fundus Er of the tested eye E. After being scattered or reflected by the fundus Er, the light beam returns to the adjustable beam splitter 1305 along the original optical path, is partially transmitted through the adjustable beam splitter 1305, passes through the adjustable receiving aperture 1303, and is finally received by the adjustable detector 1301.

[0085] The adjusting output aperture 1313 and the adjusting receiving aperture 1303 are set in a conjugate manner relative to the adjusting beam splitter 1305; the adjusting receiving aperture 1303 and the fixed light source 1701 are set in a conjugate manner relative to the fixed beam splitter 1703.

[0086] Example 3

[0087] like Figure 4 As shown, the third probe 30 of the fundus imaging optical system also includes: a fundus illumination optical path, a fundus imaging optical path, a fixation optical path, an auxiliary refractive adjustment optical path, and an iris split-image imaging optical path. The following details only the parts that differ from those in Embodiment 1; other parts are described in the same way as in Embodiment 1.

[0088] 1. Assist in adjusting the refractive path

[0089] The auxiliary diopter path includes an auxiliary diopter light source 3301, a pinhole aperture 3303, a first lens for the auxiliary diopter path 3304, a double aperture aperture 3305, a second lens for the auxiliary diopter path 3306, a fixed diopter beam splitter 1703, an eyepiece objective lens 1201, a first aperture 1203, a diopter mirror 1204, an imaging mirror 1205, a beam splitter 1206, and a camera device 1207.

[0090] In this system, light is emitted from the auxiliary refractive light source 3301. After passing through the pinhole aperture 3303, the beam is divided into two independent fine beams by the first lens 3304 and the double-aperture aperture 3305 of the auxiliary refractive optical path. These two fine beams converge at point A on the principal optical axis of the auxiliary refractive optical path after passing through the second lens 3306. Then, the two fine beams separate again, are transmitted through the fixed-beam splitter 1703, reflected by the beam splitter 1206, pass through the imaging lens 1205 and the refractive lens 1204, and then pass through the opening of the first aperture 1203. The two fine beams then converge again on the conjugate image plane Er' of the fundus of the human eye. The conjugate image plane Er' refers to the image plane formed by the eyepiece objective lens 1201 on the fundus of the human eye. The location of the conjugate image plane varies depending on the refractive power of the tested eye. After the two thin beams are focused together on the conjugate image plane Er' of the human eye's fundus, the beams separate again, pass through the eyepiece objective 1201, enter the pupil of the human eye, and finally focus together on the fundus Er of the human eye. After the fundus Er of the human eye scatters the above beams, the two scattered beams exit the human eye, pass through the eyepiece objective 1201, the first aperture 1203, the adjusting lens 1204, the imaging lens 1205, and the beam splitter 1206, and finally converge together on the imaging device 1207.

[0091] Among them, the convergence point A on the main optical axis of the auxiliary refractive optical path is conjugate with the center point of the imaging device 1207 relative to the beam splitter 1206; the center point of the fixed light source 1701 is conjugate with the convergence point A on the main optical axis of the auxiliary refractive optical path relative to the fixed refractive beam splitter 1703.

[0092] like Figure 5 As shown, the two thin beams are represented by their center lines, and the optical paths are as follows. The pinhole aperture 3303 is conjugate to the convergence point A on the principal optical axis of the auxiliary refractive path via the first lens 3304, the second lens 3306, and the center point A of the imaging device 1207. The center point A is conjugate to the center point of the beam splitter 1206 relative to the beam splitter 1206. Additionally, the center point of the fixed light source 1701 is conjugate to the convergence point A relative to the fixed refractive beam splitter 1703. This arrangement ensures that after the refractive lens 1204 is moved, the conjugate image planes Er' of different human eyes are conjugate to the pinhole aperture 3303, the imaging device 1207, and the fixed light source 1701 in pairs.

[0093] If the conjugate image plane Er' of the fundus of the tested eye E is not conjugate with the convergence point A, then the conjugate image plane Er' of the fundus E is also not conjugate with the imaging device 1207, and a clear infrared preview image or a fundus flash photograph cannot be obtained. In this case, the imaging device 1207 will capture two separate pinhole apertures 3303. When the images of the two pinhole apertures 3303 overlap due to the movement of the adjusting lens 1204, it indicates that the pinhole aperture 3303 is conjugate with the conjugate image plane Er' of the human eye's fundus, and thus conjugate with the fundus Er of the human eye. Through this method, after adjusting the adjusting lens 1204, the conjugate image plane Er' of the human eye's fundus also becomes conjugate with the imaging device 1207. Therefore, the separation and overlap of the image spots of the two pinhole apertures 3303 displayed on the screen (not shown) assists in the adjustment of refractive power in different human eyes. This is the principle of auxiliary adjustment of the optical path.

[0094] The third probe 30 determines the position of the tested eye E based on the iris split-image imaging optical path, and moves the tested eye to the working position required for fundus imaging by three-dimensionally moving the third probe 30; at the same time, it uses the auxiliary adjustment optical path to guide the adjustment lens 1204 to adjust precisely.

[0095] Once the above conditions are met, the fundus imaging optical system can drive the illumination output light path 140 to flash white light, while the camera device 1207 takes a picture simultaneously, thereby obtaining a clear color photo of the fundus of the tested eye.

[0096] This invention adds a confocal auxiliary adjustment optical path and a fixation optical path after the imaging optical path, so that fixation, auxiliary adjustment and fundus infrared preview or fundus color photography share the same adjustment lens. It is not only simple in structure and uses fewer optical path components, but also plays a precise auxiliary adjustment role.

[0097] This invention provides a fundus imaging optical system that combines fundus imaging illumination technology to automatically adjust the refractive power of different tested eyes, supplemented by iris split-image imaging for working distance alignment, and combined with synchronous adjustment of the gaze path to finally achieve fully automatic fundus imaging.

[0098] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0099] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0100] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0101] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and all such modifications, achieving the same performance or application, should be considered within the scope of protection of the present invention.

Claims

1. An optical system for fundus imaging of an eye under test, comprising: The application relates to an ophthalmic examination device, which comprises: an eye fundus illumination light path for providing a light source to illuminate the eye fundus of a measured eye; an eye fundus imaging light path comprising an accommodating lens for imaging the eye fundus of the measured eye; a fixation light path for providing a fixation mark to enable the measured eye to fixate; and an auxiliary accommodating light path which shares the accommodating lens with the eye fundus imaging light path to improve the accuracy and reliability of the accommodation; the fixation light path comprises an objective lens, a first diaphragm, an accommodating lens, an imaging lens, a fixation mark splitting lens, a fixation mark splitting lens, and a fixation light source; light from the fixation light source is reflected by the fixation mark splitting lens and the fixation mark splitting lens, transmitted through the imaging lens and the accommodating lens, passes through the first diaphragm, and is incident on the measured eye through the objective lens, and an internal fixation mark is projected onto the eye fundus of the measured eye; wherein the fixation light source and the camera are arranged in a conjugate manner relative to the fixation mark splitting lens; the auxiliary accommodating light path comprises the objective lens, the first diaphragm, the accommodating lens, the imaging lens, the fixation mark splitting lens, the fixation mark splitting lens, an accommodation splitting lens, an accommodation receiving diaphragm, an accommodation detector, an accommodation light source, and an accommodation light exit diaphragm; wherein the light emitted by the accommodation light source is partially reflected by the accommodation splitting lens, transmitted through the fixation mark splitting lens, reflected by the fixation mark splitting lens again, transmitted through the imaging lens and the accommodating lens, passes through the first diaphragm, and is incident on the measured eye through the objective lens, and finally projected onto the eye fundus of the measured eye; the light beam returns to the accommodation splitting lens along the original light path, is partially transmitted through the accommodation splitting lens, passes through the accommodation receiving diaphragm, and is finally received by the accommodation detector; the accommodation splitting lens partially transmits and partially reflects the light emitted by the accommodation light source; the accommodation light exit diaphragm and the accommodation receiving diaphragm are arranged in a conjugate manner relative to the accommodation splitting lens; and the accommodation receiving diaphragm and the fixation light source are arranged in a conjugate manner relative to the fixation mark splitting lens.

2. The fundus imaging optical system of claim 1, wherein the eye fundus illumination light path comprises an illumination light exit light path, a hole reflection mirror, and an objective lens; the light source in the eye fundus illumination light path emits light, which is reflected by the hole reflection mirror and then transmitted through the objective lens to illuminate the eye fundus of the measured eye; wherein the hole reflection mirror has a first through hole in the middle, and the annular illumination light formed by the eye fundus illumination light path is reflected by the mirror part outside the first through hole of the hole reflection mirror.

3. The fundus imaging optical system of claim 2, wherein a first diaphragm is arranged in the first through hole; the eye fundus imaging light path further comprises the objective lens, the first diaphragm, an imaging lens, a fixation mark splitting lens, and a camera; light emitted from the eye fundus passes through the objective lens, the first diaphragm, is adjusted by the accommodating lens, passes through the imaging lens and the fixation mark splitting lens, and is finally imaged on the camera; wherein the fixation mark splitting lens enables the light emitted by the illumination light exit light path to be transmitted through the fixation mark splitting lens to the camera.

4. The fundus imaging optical system of claim 1, wherein The auxiliary dioptric light path comprises an auxiliary dioptric light source, a pinhole diaphragm, an auxiliary dioptric light path first lens, a double-hole diaphragm, an auxiliary dioptric light path second lens, the fixed dioptric prism, the ocular objective, the first diaphragm, the dioptric mirror, the imaging mirror, the centration prism, and the camera device. The auxiliary dioptric light source emits light, and the light beam passes through the pinhole diaphragm, the auxiliary dioptric light path first lens, and the double-hole diaphragm, and becomes two independent fine light beams; the two fine light beams pass through the auxiliary dioptric light path second lens, and are jointly focused on a convergence point on the main optical axis of the auxiliary dioptric light path; the two fine light beams are separated again, pass through the fixed dioptric prism, are reflected by the centration prism, pass through the imaging mirror and the dioptric mirror, pass through the opening of the first diaphragm, and are jointly focused on the conjugate image plane of the fundus of the measured eye again; the two fine light beams are separated again, pass through the ocular objective, and are incident on the pupil of the measured eye, and are finally jointly focused on the fundus of the measured eye; the fundus of the measured eye scatters the light beam, and two scattered light beams are obtained, the two scattered light beams are emitted from the measured eye, pass through the ocular objective and the first diaphragm, pass through the dioptric mirror, the imaging mirror, and the centration prism, and are finally jointly focused on the camera device; The conjugate image plane is an imaging plane of the fundus of the measured eye imaged by the ocular objective; The convergence point on the main optical axis of the auxiliary dioptric light path and the center point of the camera device are conjugate with respect to the centration prism; The center point of the fixation light source and the convergence point on the main optical axis of the auxiliary dioptric light path are conjugate with respect to the fixed dioptric prism.

5. The fundus imaging optical system of claim 1, wherein The fundus illumination light path comprises an illumination light source, an illumination light filter, and an ocular objective; The illumination light source emits light, and the light beam passes through the illumination light filter and the ocular objective, and illuminates the fundus of the measured eye; The illumination light filter has a second through hole in the middle, and a second diaphragm is arranged in the second through hole; the illumination light source is symmetrically distributed with respect to the second diaphragm; The fundus imaging light path further comprises the ocular objective, the second diaphragm, an imaging filter, an imaging mirror, a centration prism, and a camera device.

6. The fundus imaging optical system of claim 5, wherein The auxiliary dioptric light path comprises the ocular objective, the second diaphragm, an imaging filter, a dioptric mirror, an imaging mirror, a centration prism, a fixed dioptric prism, a dioptric prism, a dioptric receiving diaphragm, a dioptric detector, a dioptric light source, and a dioptric light emitting diaphragm; The dioptric light source emits light, and the light beam passes through the dioptric light emitting diaphragm, is partially reflected by the dioptric prism, passes through the fixed dioptric prism, is reflected by the centration prism, passes through the imaging mirror and the dioptric mirror, passes through the imaging filter and the second diaphragm, passes through the ocular objective, and is finally incident on the fundus of the measured eye; the light beam is scattered or reflected by the fundus of the measured eye, returns to the dioptric prism along the original light path, is partially transmitted by the dioptric prism, passes through the dioptric receiving diaphragm, and is finally received by the dioptric detector; The out-coupling light diaphragm and the in-coupling light diaphragm are arranged in a conjugate manner with respect to the variable-coupling beam splitter; the in-coupling light diaphragm and the fixation light source are arranged in a conjugate manner with respect to the fixed-coupling beam splitter.

7. The fundus imaging optical system according to any one of claims 1 to 6, wherein The fundus imaging optical system further comprises an iris split imaging optical path, the iris split imaging optical path comprising an iris illumination light source and two iris split imaging sub-paths, the two iris split imaging sub-paths being arranged on the left and right sides of the objective lens, respectively; each of the two iris split imaging sub-paths comprising an iris filter, an iris imaging lens, and an iris camera device. The light emitted by the iris illumination light source is irradiated to the anterior chamber of the eye to be measured, the light is reflected by the anterior chamber tissue, the reflected light passes through the iris filter and the iris imaging lens, and is finally captured by the iris camera device.

8. The fundus imaging optical system of claim 7, wherein, The working position of the eye to be measured is determined by the intersection of the main optical axes of the two sub-paths and the main optical axis of the probe optical path. Alternatively, the two sub-paths are used to obtain the upper and lower anterior chamber images of the eye to be measured, respectively, and the working distance is determined by image stitching of the upper and lower anterior chamber images.

Images