Dry eye detection optical system and detection method thereof

Abstract

The invention discloses a dry eye detection optical system and a detection method thereof, the dry eye detection optical system comprises an imaging light path, the imaging light path comprises a dichroscope, one side of the dichroscope is provided with an internal fixation imaging assembly, and the internal fixation imaging assembly corresponds to an object plane side; an imaging lens group is arranged on the other side of the dichroscope, and the other side of the imaging lens group corresponds to the image surface; and the light path of the internal fixation imaging assembly is coupled into the imaging light path through the dichroscope. The invention discloses a dry eye detection optical system and a detection method thereof. The dry eye detection optical system has the advantages of broadband, continuous zooming, different object distance focusing, compact structure, high imaging quality and easy processing and adjustment.

Description

Technical Field

[0001] The present invention relates to the technical field of optical equipment, and in particular to a dry eye detection optical system and a detection method thereof. Background Art

[0002] With the increasing use of electronic products in people's work and life, dry eyes have become a common and important ophthalmic disease, seriously affecting patients' visual function and health. The incidence of dry eyes in my country is about 21%~30%, exceeding 300 million people. According to Global Data statistics, the number of dry eye patients in the world increases by 0.7% each year. China has the largest number of dry eye patients in the world. By 2026, the number of confirmed dry eye patients in my country will reach 64 million, and the base of dry eye patients is huge.

[0003] The dry eye detection optical system is an advanced ocular surface photography device that can provide ocular surface images in a more time-saving, accurate, fast and non-invasive manner, with the advantages of fast imaging, ultra-high resolution, fast zoom, and large imaging range. Doctors can complete a series of dry eye examination items in a very short time, which greatly facilitates doctors to diagnose patients' dry eye conditions.

[0004] Currently, the dry eye detectors on the market can be divided into two routes: one is based on corneal topography, and the other is based on slit lamp upgrades. Brands based on corneal topography include OCulus, Antares, Zhiding, and Sovi, etc.; brands based on slit lamp upgrades include Kanghua, Meiwo, and Shangbang, etc. For dry eye detectors based on corneal topography, most parameters have a certain meaning for corneal topography, and the dry eye examination function is an additional function; equipment based on slit lamp upgrades has certain functional limitations, and the working distance of the equipment is short, and there is a possibility that the equipment will come into contact with the human eye.

[0005] Dry eye testing often includes several different test items, the most common ones are tear meniscus height, tear film breakup time, meibomian gland analysis, eyelid margin analysis, lipid layer analysis, corneal staining analysis, etc. Different test items have different focuses. When measuring tear meniscus height, the optical system needs to be focused on the tear meniscus of the eye. The greater the magnification, the more obvious the observation of tear meniscus height. Therefore, compared with other test items, a higher optical magnification is required for tear meniscus height measurement. When performing red eye analysis, the image of the entire eye needs to be collected. Compared with other test items, red eye analysis requires a larger linear field of view. In addition, when performing lipid layer detection, the flow of the lipid layer on the tear film can only be clearly seen under the white light band. When performing meibomian gland detection, the meibomian glands can only be clearly seen in the near-infrared band.

[0006] Therefore, we have developed a wide-band wavelength, which is compatible with imaging at different wavelengths; has variable field of view imaging; and a dry eye detection optical system with different working distances. This system is used in the diagnosis of different dry eye conditions and has good market prospects. Summary of the invention

[0007] The present invention overcomes the deficiencies of the prior art and provides a dry eye detection optical system and a detection method thereof which has a wide band, continuous magnification, focusing at different object distances, a compact structure, high imaging quality, and is easy to process and assemble.

[0008] To achieve the above-mentioned object, the technical solution adopted by the present invention is: an optical system for dry eye detection, comprising: an imaging optical path, the imaging optical path comprising: a dichroic mirror, one side of the dichroic mirror is provided with an internal fixation imaging component, and the internal fixation imaging component corresponds to the object plane side; the other side of the dichroic mirror is provided with an imaging lens group, and the other side of the imaging lens group corresponds to the image plane; The optical path of the internal fixation imaging component is coupled into the imaging optical path through the dichroic mirror.

[0009] A preferred embodiment of the present invention further includes an illumination light path for providing a light source for the imaging light path, and the illumination light path includes an illumination light source for providing light to the cornea.

[0010] In a preferred embodiment of the present invention, the illumination light path includes: a placido disk (a placido corneal disk) arranged on the imaging light path; the placido disk is located between the cornea and the imaging light path, a reflection cavity is arranged on the outer side of the placido disk, and the light of the imaging light path can pass through the central through hole of the placido disk and the reflection cavity.

[0011] In a preferred embodiment of the present invention, the illumination light source is located between the placido disk and the reflective cavity; the light from the illumination light source is introduced between the reflective cavity and the placido disk, and is scattered by the reflective cavity, passes through the placido disk, is introduced to the cornea, and then enters the imaging light path.

[0012] Specifically, the illumination optical path is mainly composed of a placido ring and an illumination lamp bead. The light emitted by the lamp bead is evenly scattered by the reflection cavity and then penetrates the Placido disk for illumination imaging. At this time, the light of the Placido disk not only illuminates the human eye, but also projects the Placido ring onto the cornea to detect the eye. The imaging optical path is mainly composed of an optical lens. It collects the light projected by the Placido ring onto the cornea and forms an image on the camera. The change of viewing angle is achieved by switching between lens groups or moving between lens groups.

[0013] In a preferred embodiment of the present invention, the imaging lens group includes a front fixed component, a magnification component, a compensation component, and a rear fixed component which are sequentially arranged between the dichroic mirror and the image plane; and an aperture for opening and closing the light path is also arranged between the magnification component and the compensation component.

[0014] Specifically, the front fixed component, the zoom component, the compensation component, and the rear fixed component of the present invention adopt the structure of the prior art to form a zoom system. In order to realize the zoom function, at least one group of zoom components can be moved, namely the zoom group and the compensation group. After the zoom group moves, the focal length and imaging angle of the system will change, and the compensation group will move to compensate for the aberration caused by the movement of the zoom group. In addition, the front fixed group is to balance the aberration of the incident light, and the rear fixed group is to further correct the aberration of the outgoing light.

[0015] In a preferred embodiment of the present invention, the imaging lens group includes a rotating wheel for switching the optical imaging lens, and the rotating wheel is provided with a plurality of imaging lens groups with different parameters. By rotating or moving the rotating wheel to switch the imaging lens groups in different positions, the magnification switching within the linear field of view is realized.

[0016] In a preferred embodiment of the present invention, the distance between the first lens of the imaging lens group and the object plane is fixed, the distance between the dichroic mirror and the imaging lens group is fixed, and the distance between the aperture and the dichroic mirror is fixed. When different imaging lens groups are connected to the optical system, focusing can be achieved by fine-tuning the second lens in the imaging lens group.

[0017] In a preferred embodiment of the present invention, the illumination light source adopts one or more of white light, infrared light and blue light of different wavelengths.

[0018] In a preferred embodiment of the present invention, the imaging optical path adopts an achromatic design, and / or the illumination lamp beads used by the illumination light source (204) are LED lamps, or light sources that have undergone uniform light treatment.

[0019] Specifically, imaging in the visible light band and near-infrared band is achieved, and a more accurate picture of the human eye condition can be obtained by analyzing the human eye in different bands.

[0020] Specifically, the achromatic design includes different wavelengths having different focal lengths through the same lens; chromatic aberration is balanced by using multiple lenses for the entire system to ensure that the imaging quality of different wavelengths is high.

[0021] Specifically, imaging in the visible light band and near-infrared band can illuminate the human eye by lighting up lamp beads of different wavelengths. Under illumination of different wavelengths, the human eye can collect different physiological information by the camera. For example, under illumination of the 880 band, the camera can collect the meibomian glands of the human eye.

[0022] In a preferred embodiment of the present invention, the imaging optical path adopts an image-side telecentric design.

[0023] Specifically, it reduces the difficulty of detector installation and alignment. At the same time, image-space telecentricity not only makes the illumination of the detector target imaging uniform, but also facilitates later splicing with different systems. Furthermore, image-space telecentricity design means that the incident light at the image plane position is perpendicular to the image plane, that is, the incident light is parallel to the optical axis, and the incident angle is 0 degrees. The image-space telecentricity design can make the illumination received by the detector more uniform, avoiding the phenomenon of high illumination at the center of the image plane and low illumination at the edge, or low illumination at the center and high illumination at the edge due to different incident angles of light in other non-image-space telecentric designs. Therefore, when installing and aligning, the position of the detector target surface can be easily adjusted.

[0024] Specifically, the internal fixation imaging component (30) can guide the human eye, thereby reducing the difficulty of photographing the human eye. Furthermore, the internal fixation light source is focused on the retina of the human eye through a lens, thereby guiding the gaze direction of the human eye.

[0025] In a preferred embodiment of the present invention, a detection method of a dry eye detection optical system is implemented using the dry eye detection optical system, comprising the following steps: The light emitted by the illumination light source of the illumination light path is evenly scattered by the reflection cavity and then penetrates the Placido disk for illumination imaging. At this time, the light of the Placido disk realizes illumination of the human eye and projects the Placido ring of the Placido disk onto the cornea to realize eye detection.

[0026] The imaging optical path collects the light projected onto the cornea by the Placido ring of the Placido disk and forms an image on the camera. The change of viewing angle is achieved by switching between imaging lens groups or moving between lens groups in the imaging lens group.

[0027] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a dry eye detection optical system and a detection method thereof which have wide band, continuous variable magnification, focusing at different object distances, compact structure, high imaging quality, and are easy to process and assemble.

[0028] 1. In the dry eye detection optical system of the present invention, the illumination light path can achieve uniform illumination of visible + near-infrared to the human eye.

[0029] 2. The dry eye detection optical system of the present invention adopts an achromatic optical design, and its working band is visible + near-infrared. The band is relatively wide and can be compatible with various modes required for fundus application (different modes have different application wavelengths).

[0030] 3. The dry eye detection optical system of the present invention adopts a zoom system, which can realize different line field conversion and continuous zoom.

[0031] 4. The dry eye detection optical system of the present invention has a focusing system that can focus at different object distances.

[0032] 5. The dry eye detection optical system of the present invention uses a telecentric optical path when designing to improve the uniformity of the image plane illumination and facilitate the subsequent connection with other optical systems; at the same time, a full-face mirror reduces the difficulty of processing, installation, and alignment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0034] Figure 1 It is a placido disk and a reflective cavity of an illumination system of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 2 is a schematic diagram of a placido ring of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 3 is a light path layout diagram of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 4 is a light path layout diagram of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 5 is a cam curve of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 6 is a focusing schematic diagram of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 7 is an optical path layout diagram of a 10 mm line field dry eye optical detection system of a dry eye detection optical system in a preferred embodiment of the present invention; Figure 8 is an optical path layout diagram of a 16mm line field dry eye optical detection system of a dry eye detection optical system in a preferred embodiment of the present invention; Fig. 9 is an optical path layout diagram of a 26mm line field dry eye optical detection system of a dry eye detection optical system in a preferred embodiment of the present invention; Fig.10 is a schematic diagram of a rotating wheel for switching the field of view of a dry eye detection optical system in a preferred embodiment of the present invention; Fig.11 It is a schematic diagram of a 10 mm line field imaging lens assembly support of a dry eye detection optical system in a preferred embodiment of the present invention; Fig.12 is a schematic diagram of a 16 mm line field imaging lens assembly support of a dry eye detection optical system in a preferred embodiment of the present invention; Fig.13 It is a schematic diagram of a 26 mm line field imaging lens assembly support of a dry eye detection optical system in a preferred embodiment of the present invention; Among them, 10-object plane, 20-dichroic mirror, 30-internal fixation imaging component, 40-front fixed component, 50-zoom component, 60-aperture, 70-compensation component, 80-rear fixed component, 90-image plane, 201-placido disk, 202-cornea, 203-reflection cavity, 204-illumination light source, 300-rotating wheel, 100-10mm imaging mirror group one, 101-16mm imaging mirror group two, 102-26mm imaging mirror group three. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0036] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship. Example 1

[0037] like Figure 1 , Figure 2 As shown, the present invention discloses a dry eye detection optical system, including: an imaging light path, and an illumination light path providing a light source for the imaging light path.

[0038] Specifically, the imaging optical path includes: a dichroic mirror 20, one side of the dichroic mirror 20 is provided with an internal fixation imaging component 30, and the internal fixation imaging component 30 corresponds to the object plane 10 side; the other side of the dichroic mirror 20 is provided with an imaging lens group 1, and the other side of the imaging lens group 1 corresponds to the image plane 90; the optical path of the internal fixation imaging component 30 is coupled into the imaging optical path through the dichroic mirror 20. Furthermore, the imaging optical path is mainly composed of optical lenses. It collects the light projected onto the cornea by the Placido ring and images it on the camera. The change of viewing angle is achieved by switching between lens groups or moving between lens groups. The imaging optical path in the dry eye detection optical system uses focusing to achieve focusing at different object distances.

[0039] Specifically, the illumination light path includes an illumination light source 204 that provides light to the cornea 202. The illumination light path includes: a placido disk 201 disposed on the imaging light path; the placido disk 201 is located between the cornea 202 and the imaging light path, a reflection cavity 203 is disposed on the outer side of the placido disk 201, and the light of the imaging light path can pass through the central through hole of the placido disk 201 and the reflection cavity 203. Further, the illumination light source 204 is located between the placido disk 201 and the reflection cavity 203; the light of the illumination light source 204 is introduced between the reflection cavity 203 and the placido disk 201, and is scattered by the reflection cavity 203, passes through the placido disk 201, leads to the cornea 202, and then enters the imaging light path. Specifically, the illumination light path is mainly composed of a placido ring and an illumination lamp bead. The light emitted by the lamp bead is evenly scattered by the reflection cavity, and then penetrates the Placido disk to perform illumination imaging. At this time, the light from the Placido disk not only illuminates the human eye, but also projects the Placido ring onto the cornea to detect the eye.

[0040] Specifically, the imaging optical path adopts an achromatic design, and the lighting lamp beads used in the lighting light source 204 are LED lamps, or light sources that have been treated with uniform light. Imaging in the visible and near-infrared bands is achieved, and the human eye is analyzed by different bands to obtain a more accurate human eye condition. The imaging optical path adopts an image-side telecentric design. The difficulty of detector installation and alignment is reduced. At the same time, the image-side telecentricity not only makes the imaging illumination of the detector target uniform, but also facilitates later splicing with different systems. The internal fixation imaging component 30 can guide the human eye and reduce the difficulty of photographing the human eye. Furthermore, the lighting light source 204 adopts one or more of white light, infrared light, and blue light of different wavelengths. More specifically, the lighting light source adopts a variety of light sources such as white light, 850nm infrared light, 880nm infrared light, and 465nm blue light. The light source has stable lighting power, good thermal stability, strong uniformity, and low cost, which is convenient for later processing and installation.

[0041] Working principle: The placido disk and reflective cavity of the lighting system, the light emitted from the lighting source 204 is Figure 1 After the uniform light is reflected by the reflection cavity 203 in the lens, it passes through the placido disk 201 to illuminate the ocular surface, and at the same time, the placido ring on the placido disk 201 is projected onto the cornea 202. The placido ring of the illumination system is as shown in FIG. Figure 2 As shown, the ocular surface image is finally captured by the imaging optical path. Example 2

[0042] This embodiment 2 provides a dry eye detection lighting system, see the attached Figure 3This is the optical path layout diagram of the dry eye detection optical system. The dry eye detection lighting system uses the principle of optical projection. The light emitted by the lamp beads is evenly scattered by the reflection cavity and then penetrates the placido disk for illumination imaging. At this time, the light of the placido disk not only illuminates the human eye, but also projects the placido ring onto the cornea. In addition, the infrared lamp beads and blue light lamp beads on the surface of the placido disk can be used to illuminate the meibomian glands and fluorescent staining. The lighting system adopts the method of evenly scattering light in the reflection cavity, which has uniform lighting, large light radiation area, compact structure, and simple processing and assembly.

[0043] Figure 1 The placido disk and reflective cavity of the illumination system, the light emitted from the illumination light source 204 is Figure 1 After the uniform light is reflected by the reflection cavity 203 in the lens, it passes through the placido disk 201 to illuminate the ocular surface, and at the same time, the placido ring on the placido disk 201 is projected onto the cornea 202. The placido ring of the illumination system is as shown in FIG. Figure 2 As shown, the ocular surface image is finally captured by the imaging optical path.

[0044] In this implementation case 2, the lighting source adopts a variety of light sources such as white light, 850nm infrared light, 880nm infrared light and 465nm blue light. The light source has stable lighting power, good thermal stability, strong uniformity, and low cost, which is convenient for later processing and installation. Example 3

[0045] This embodiment 3 provides a dry eye detection optical system, which uses the optical principles of magnification and zoom to achieve continuous magnification of 9mm~27mm line field of view and zoom at different object distances; at the same time, it uses the achromatic principle to achieve 0.4μm~1.0μm wide-band imaging, which is convenient for collecting human eye information using different wavelengths; the optical system adopts a catadioptric type with a compact structure, high imaging quality and good thermal stability; a full-spherical lens is used to facilitate post-processing and assembly.

[0046] Specifically, the imaging lens group 1 includes a front fixed component 40, a magnification component 50, a compensation component 70, and a rear fixed component 80, which are sequentially arranged between the dichroic mirror 20 and the image plane 90; and an aperture 60 for opening and closing the light path is also arranged between the magnification component 50 and the compensation component 70.

[0047] See attached Figure 4 , which is the optical path layout diagram of the dry eye detection optical system provided in this embodiment. Along the incident direction of the light, first there is the object plane 10, the dichroic mirror 20, the internal fixation imaging part 30, the front fixed group part 40, the zoom group part 50, the aperture 60, the compensation group part 70, the rear fixed group part 80; the image plane 90.

[0048] Specifically, the linear field of view is continuously changed from 9 mm to 27 mm by the mutual movement between the zoom group 50 and the compensation group 70; Figure 4 is the motion curve of the zoom group 50 and the compensation group 70, wherein the zoom group 50 performs linear motion and the compensation group 70 performs nonlinear motion to compensate for the image plane drift caused by the movement of the zoom group 50. For specific cam curve diagrams, see the attached Figure 3 , where the straight line is the motion curve of the zoom group 50, and the curved line is the motion curve of the compensation group 70.

[0049] The internal fixation portion 30 mainly guides the human eye; at the same time, the internal fixation optical path is coupled into the continuous zoom optical path through the dichroic mirror 20.

[0050] Since the optical path adopts an achromatic design, wide-band imaging from 0.4μm to 1.0μm can be achieved.

[0051] When designing the optical path, a telecentric optical path is used to reduce the difficulty of detector installation and alignment. At the same time, image-side telecentricity can not only make the detector target imaging illumination uniform, but also facilitate later splicing with different systems.

[0052] At the same time, all lenses are spherical, which reduces the difficulty of processing, installation and alignment. Example 4

[0053] Based on the embodiment 3, the present embodiment 4 provides a focusing method for a dry eye detection optical system. At the same time, due to the distance relative to the human eye during acquisition (i.e., the object distance is different), the lens 801 in the rear fixed group can be used for focusing. Figure 6 When the distance to the object plane 10 changes, focusing is performed by moving the position of the lens 801. Example 5

[0054] This implementation example 5 is based on this embodiment 1 or this embodiment 2, and provides a dry eye detection optical system, which uses multiple groups of fixed optical lenses to rotate directly to form an image, and realizes fixed-point magnification within the 10mm-26mm linear field of view and zooming at different object distances. At the same time, the principle of achromatism is used to achieve 0.4μm~1.0μm wide-band imaging, which is convenient for collecting human eye surface information by using light sources of different bands. Each group of lenses in the optical system has a simple structure, high imaging quality, high thermal stability, and a spherical lens, which is low in cost and easy to process and adjust later.

[0055] See also Figure 7 It is one of the imaging optical path layouts of the dry eye detection optical system provided in this embodiment. Along the incident direction of the light, first there is the object plane 10, the aperture 60, the dichroic mirror 20, the internal fixation imaging part 30, the 10mm imaging lens group 100, and the image plane 90. Figure 8~Figure 9This is the imaging optical path layout of the dry eye detection optical system with a linear field of view of 16mm and 26mm.

[0056] See also Fig.10 The imaging lens group 1 includes a rotating wheel 300 for switching optical imaging lenses. The rotating wheel 300 is provided with a plurality of imaging lens groups with different parameters. By rotating or moving the rotating wheel 300 to switch the imaging lens groups in different positions, the magnification switching within the linear field of view is realized. Furthermore, the distance between the first lens of the imaging lens group 1 and the object plane 90 is fixed, the distance between the dichroic mirror 20 and the imaging lens group 1 is fixed, and the distance between the diaphragm 60 and the dichroic mirror 20 is fixed. When different imaging lens groups 1 are connected to the optical system, the second lens in the imaging lens group 1 can be fine-tuned for focusing. Specifically, the lens of the lens in the imaging lens group 1 is a spherical lens, which reduces the difficulty of processing, adjustment, and alignment. By switching the lens group or moving the relative distance between the lenses to change the magnification, clear imaging of different linear fields of view can be achieved to meet different functional requirements.

[0057] The present embodiment provides a rotating wheel 300 for switching optical imaging lenses. Lenses of different magnifications, such as 10mm imaging lens group 1 100, 16mm imaging lens group 2 101, and 26mm imaging lens group 3 102, are fixed on the rotating wheel 300. The rotation realizes the magnification change of the entire optical system within the linear field of view range of 10-26mm. Fig.11 , Fig.12 , Fig.13 The mirror groups required for switching are 10mm, 16mm, and 26mm line field imaging. The inner fixation part 30 mainly guides the human eye; at the same time, the inner fixation optical path is coupled into the imaging optical path through the dichroic mirror 20.

[0058] When designing the optical path, the distance between the first lens of the multiple imaging lens groups and the object plane 90 is fixed, the distance between the dichroic mirror 20 and the imaging lens group is fixed, and the distance between the aperture 60 and the dichroic mirror 20 is fixed, which is convenient for different imaging lens groups to be connected to the optical system, and the second lens in the imaging lens group can be fine-tuned for focusing. At the same time, all lenses are spherical lenses, which reduces the difficulty of processing, installation, and alignment.

[0059] From the above, it can be seen that the dry eye detection optical system provided by the patent of the present invention can achieve clear imaging within the visible and near-infrared wavelength range; at the same time, by utilizing the variable magnification design principle, it can realize continuous change of the linear field of view and clear imaging; by utilizing the focusing device, clear imaging of different object distances can be achieved; the entire system uses spherical mirrors, which have a compact structure, high imaging quality, and are conducive to processing and assembly; it can be used in the medical industry to diagnose various ophthalmic diseases such as dry eyes. Example 6

[0060] On the basis of any one of Embodiments 1 to 5, a detection method of a dry eye detection optical system is implemented by using the dry eye detection optical system, comprising the following steps: The light emitted by the illumination light source 204 of the illumination light path is evenly scattered by the reflection cavity 203 and then penetrates the Placido disk 201 to perform illumination imaging. At this time, the light of the Placido disk 201 realizes illumination of the human eye, and at the same time, the Placido ring of the Placido disk 201 is projected onto the cornea 202 to realize detection of the eye.

[0061] The imaging optical path collects the light projected from the Placido ring of the Placido disk 201 onto the cornea 202 and forms an image on the camera. The change of viewing angle is achieved by switching between the imaging lens groups 1 or moving between the lens groups in the imaging lens group 1 .

[0062] Working principle: A dry eye detection optical system and detection method thereof with a wide band, continuous zoom, focusing at different object distances, compact structure, high imaging quality, and easy processing and assembly. In the dry eye detection optical system of the present invention, the illumination light path can realize uniform irradiation of visible + near-infrared to the human eye. The dry eye detection optical system of the present invention adopts an achromatic optical design, and the working band is visible + near-infrared. The band is relatively wide and can be compatible with various modes required for fundus demand applications (different modes have different application wavelengths). The dry eye detection optical system of the present invention adopts a zoom system, which can realize different line field conversion and continuous zoom. The dry eye detection optical system of the present invention has a focusing system that can focus on different object distances. The dry eye detection optical system of the present invention uses a telecentric optical path in the design to improve the uniformity of the illumination of the image plane and facilitate the subsequent docking with other optical systems; at the same time, a full-spherical mirror is used to reduce the difficulty of processing, assembly, and alignment.

[0063] The present invention is a catadioptric optical system with an operating band of 0.4μm to 1.0μm. Through relative displacement between lenses, continuous magnification of different linear fields of view can be achieved; or imaging of different fields of view can be achieved by switching lens groups; a lens in the optical system can be moved to achieve focusing at different object distances. In order to guide the human eye during the imaging process, the optical system also has an internal fixation imaging part. The optical system images the human eye and finally presents the image on the detector for subsequent analysis. The patent of the present invention has a wide applicable band, so it can simultaneously image and analyze the human eye in visible and near-infrared light; its spherical aberration and distortion are small, and the imaging quality is close to the diffraction limit; the image space is telecentric and the illumination of the image plane is uniform; the structure is compact, and the processing and manufacturing costs are low; the energy utilization rate is high, the light-gathering ability is strong, the thermal adaptability is good, and the installation and detection are easy. It can be applied to the diagnosis of ophthalmic diseases in the medical field.

[0064] Based on the ideal embodiment of the present invention, through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A dry eye detection optical system, characterized in that: include: An imaging optical path, the imaging optical path comprising: a dichroic mirror (20), an inner fixation imaging component (30) being provided on one side of the dichroic mirror (20), and the inner fixation imaging component (30) being corresponding to a side of an object plane (10); an imaging lens group (1) being provided on the other side of the dichroic mirror (20), and the other side of the imaging lens group (1) being corresponding to an image plane (90); The optical path of the internal fixation imaging component (30) is coupled into the imaging optical path through the dichroic mirror (20).

2. The dry eye detection optical system according to claim 1, characterized in that: It also includes an illumination light path that provides a light source for the imaging light path, and the illumination light path includes an illumination light source (204) that provides light to the cornea (202).

3. The dry eye detection optical system according to claim 2, characterized in that: The illumination light path comprises: a placido disk (201) arranged on the imaging light path; the placido disk (201) is located between the cornea (202) and the imaging light path, a reflection cavity (203) is arranged on the outside of the placido disk (201), and light of the imaging light path can pass through the central through holes of the placido disk (201) and the reflection cavity (203).

4. The dry eye detection optical system according to claim 3, characterized in that: The illumination light source (204) is located between the placido disk (201) and the reflection cavity (203); light from the illumination light source (204) is introduced between the reflection cavity (203) and the placido disk (201), is scattered by the reflection cavity (203), passes through the placido disk (201), is guided to the cornea (202), and then enters the imaging light path.

5. The dry eye detection optical system according to claim 4, characterized in that: The imaging lens assembly (1) comprises a front fixed component (40), a magnification component (50), a compensation component (70), and a rear fixed component (80) which are sequentially arranged between the dichroic mirror (20) and the image plane (90); and a diaphragm (60) for opening and closing an optical path is also arranged between the magnification component (50) and the compensation component (70).

6. The dry eye detection optical system according to claim 4, characterized in that: The imaging lens group (1) comprises a rotating wheel (300) for switching optical imaging lenses, and a plurality of imaging lens groups with different parameters are arranged on the rotating wheel (300). By rotating or moving the rotating wheel (300) to switch imaging lens groups at different positions, variable magnification switching within a linear field of view is achieved.

7. The dry eye detection optical system according to claim 4, characterized in that: The distance between the first lens of the imaging lens group (1) and the object plane (90) is fixed, the distance between the dichroic mirror (20) and the imaging lens group (1) is fixed, and the distance between the diaphragm (60) and the dichroic mirror (20) is fixed. When different imaging lens groups (1) are connected to an optical system, focusing can be performed by fine-tuning the second lens in the imaging lens group (1).

8. The dry eye detection optical system according to claim 5 or 6, characterized in that: The illumination light source (204) uses one or more of white light, infrared light, and blue light with different wavelengths; And / or, the imaging optical path adopts an achromatic design; And / or, the lighting lamp beads used by the lighting light source (204) are LED lamps, or light sources that have undergone light uniformity treatment.

9. The dry eye detection optical system according to claim 8, characterized in that: The imaging optical path adopts image-space telecentric design.

10. A method for detecting a dry eye detection optical system, characterized in that: The dry eye detection optical system according to any one of claims 1 to 9 is used for implementation, comprising the following steps: The light emitted by the illumination light source (204) of the illumination light path is evenly scattered by the reflection cavity (203) and then penetrates the Placido disk (201) to perform illumination imaging; at this time, the light of the Placido disk (201) realizes illumination of the human eye, and at the same time, the Placido ring of the Placido disk (201) is projected onto the cornea (202) to realize detection of the eye; The imaging optical path collects light projected from the Placido ring of the Placido disk (201) onto the cornea (202) and forms an image on the camera, and changes in viewing angle are achieved by switching between imaging lens groups (1) or moving between lens groups in the imaging lens group (1).

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