Fundus imaging system and method based on line scanning confocal

Abstract

The invention provides a line scanning confocal-based fundus imaging system and method, and relates to the technical field of fundus imaging, and the system comprises a scanning unit which carries out the one-dimensional scanning of a linear confocal light beam emitted by an illumination unit, and projects the linear confocal light beam to a fundus region; the imaging lens group is used for imaging fundus information carried by the detection light path separated by the light splitting element on the area array image sensor; the area array image sensor works in a rolling shutter mode and receives an image formed by the imaging lens group in a line-by-line exposure mode; and the image processing unit is used for reading image data of line-by-line exposure of the area array image sensor and reconstructing continuous line scanning images in a time sequence into a complete two-dimensional fundus image. According to the line scanning confocal-based fundus imaging system and method provided by the invention, the axial broadening line confocal illumination is combined with a camera rolling shutter mechanism, so that selective acquisition of effective signals of the fundus in a compact system structure is realized.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fundus imaging, in particular to a fundus imaging system and method based on line-scan confocal. BACKGROUND

[0002] Fundus imaging technology is to take a high-definition photo of the "negative" of the eye, the retina. This photo can not only see the diseases of the eye itself, but also provide diagnostic basis for various diseases, which has great significance for human health monitoring.

[0003] The confocal fundus camera in the related art has certain advantages in suppressing stray light and improving image contrast, but due to the point scanning and pinhole detection mode, the single-point collection efficiency is low, and a high-speed and high-precision scanning mechanism is needed to complete large-range imaging, which not only has high system complexity, but also has relatively large cost. SUMMARY

[0004] The purpose of the application is to provide a fundus imaging system and method based on line-scan confocal, which realizes selective collection of effective signals of the fundus in a compact system structure by combining the axially widened line confocal illumination with the camera rolling shutter mechanism.

[0005] The application provides a fundus imaging system based on line-scan confocal, which comprises:

[0006] An illumination unit for generating a line-shaped confocal light beam, a scanning unit arranged in the illumination light path, a light splitting element for separating the illumination light path from the reflected light path from the fundus, an imaging lens group, a face array image sensor, and an image processing unit; the scanning unit is used for one-dimensional scanning of the line-shaped confocal light beam emitted by the illumination unit and projecting to the fundus area; the line-shaped confocal light beam forms a line-shaped illumination band on the retina surface after entering the eyeball through the pupil; the imaging lens group is used for imaging the fundus information carried by the detection light path separated by the light splitting element on the face array image sensor; the face array image sensor works in a rolling shutter mode and receives the image formed by the imaging lens group through a row-by-row exposure mode; the image processing unit is used for reading the image data of row-by-row exposure of the face array image sensor and reconstructing the time-sequentially continuous line-scan images into a complete two-dimensional fundus image; wherein the motion trajectory of the effective exposure row of the rolling shutter on the sensor target surface is synchronized with the scanning trajectory of the line-shaped confocal light beam on the retina, so that at any time, only the light signal reflected by the illuminated focal plane line area on the retina is received by the corresponding row of pixels on the sensor which is being exposed, thereby realizing the confocal optical slicing effect.

[0007] Optionally, a single row exposure time of the area array image sensor in the rolling shutter mode matches with an intensity distribution of the linear confocal light beam at the retinal focal plane and a scanning speed of the linear confocal light beam, so as to optimize a confocal filtering effect and an image signal-to-noise ratio.

[0008] Optionally, a row height of the rolling shutter is determined based on an expected exposure time, and the expected exposure time is an exposure time expected by a user in a shooting scene.

[0009] Optionally, the system further comprises a control unit, and the control unit is configured to generate a synchronization control signal and send the synchronization control signal to the scanning unit and the area array image sensor respectively, so that a scanning motion of the scanning unit and a rolling shutter exposure of the area array image sensor are kept synchronous in time sequence.

[0010] Optionally, the control unit is configured to generate a first control signal, a second control signal and a third control signal, the first control signal is configured to control the illumination unit to generate the linear confocal light beam, the second control signal is configured to control the scanning unit to perform one-dimensional scanning, and the third control signal is configured to control the rolling shutter exposure of the area array image sensor, and the first control signal, the second control signal and the third control signal are synchronously triggered.

[0011] Optionally, a line scanning direction of the light splitting element is consistent with a rolling direction of the camera in space.

[0012] The application also provides a fundus imaging method based on line scanning confocal, comprising:

[0013] synchronization control signals are generated, and a scanning motion of a scanning unit of the fundus imaging system based on line scanning confocal and a rolling shutter exposure of an area array image sensor of the fundus imaging system based on line scanning confocal are kept synchronous in time sequence based on the synchronization control signals; image data exposed by the area array image sensor row by row are read, and line scanning images in time sequence are reconstructed into a complete two-dimensional fundus image.

[0014] Optionally, the synchronization control signals are generated, and the scanning motion of the scanning unit of the fundus imaging system based on line scanning confocal and the rolling shutter exposure of the area array image sensor of the fundus imaging system based on line scanning confocal are kept synchronous in time sequence based on the synchronization control signals, comprising: a first control signal, a second control signal and a third control signal are generated; the first control signal is sent to the illumination unit, the second control signal is sent to the scanning unit, and the third control signal is sent to the area array image sensor.

[0015] Optionally, the first control signal is configured to control the illumination unit to generate a linear confocal light beam; the second control signal is configured to control the scanning unit to perform one-dimensional scanning; and the third control signal is configured to control the exposure of the rolling shutter of the area array image sensor; and the first control signal, the second control signal and the third control signal are synchronously triggered.

[0016] The application also provides a computer program product, comprising computer programs / instructions, which, when executed by a processor, implement the steps of the line-scan confocal fundus imaging method according to any one of the above.

[0017] The application also provides an electronic device, comprising the line-scan confocal fundus imaging system, a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the line-scan confocal fundus imaging method according to any one of the above when executing the program.

[0018] The application also provides a computer-readable storage medium, which stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the line-scan confocal fundus imaging method according to any one of the above.

[0019] The application provides a line-scan confocal fundus imaging system and method, which comprises an illumination unit for generating a linear confocal light beam, a scanning unit arranged in the illumination light path, a light splitting element for separating the illumination light path from the reflected light path from the fundus, an imaging lens group, an area array image sensor and an image processing unit; the scanning unit is configured to perform one-dimensional scanning on the linear confocal light beam emitted by the illumination unit and project it to the fundus region; the linear confocal light beam forms a linear illumination band on the retina surface after entering the eyeball through the pupil; the imaging lens group is configured to image the fundus information carried by the detection light path separated by the light splitting element on the area array image sensor; the area array image sensor works in a rolling shutter mode and receives the image formed by the imaging lens group through line-by-line exposure; the image processing unit is configured to read the image data of line-by-line exposure of the area array image sensor and reconstruct the time-sequentially continuous line-scan images into a complete two-dimensional fundus image; wherein the motion trajectory of the effective exposure line of the rolling shutter on the sensor target surface is synchronized with the scanning trajectory of the linear confocal light beam on the retina, so that at any moment, only the light signal reflected by the illuminated focal plane line region on the retina is received by the corresponding row of pixels on the sensor which is being exposed, thereby realizing the confocal optical slicing effect. In this way, by combining the axially widened linear confocal illumination with the camera rolling shutter mechanism, the selective collection of the effective signal of the fundus in a compact system structure is realized. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0021] Figure 1 is a schematic diagram of a rolling shutter provided by the application;

[0022] Figure 2 is a structural schematic diagram of an eye fundus imaging system based on line scanning confocal provided by the application;

[0023] Figure 3 is a schematic diagram of line confocal beam scanning imaging provided by the application;

[0024] Figure 4 is a signal synchronization control schematic diagram of line confocal beam scanning imaging provided by the application;

[0025] Figure 5 is a flowchart of an eye fundus imaging method based on line scanning confocal provided by the application;

[0026] Figure 6 is a structural schematic diagram of an electronic device provided by the application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the application clearer, the technical solutions in the application will be described clearly and completely in the following with reference to the drawings in the application. Obviously, the described embodiments are some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the application.

[0028] The terms "first", "second", etc. in the specification and claims of the application are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that the data used in this way can be exchanged under appropriate circumstances, so that the embodiments of the application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually a category, not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0029] To address the aforementioned technical problems in related technologies, this application provides a fundus imaging system based on linear confocal scanning. This system combines axially widened linear confocal illumination with a rolling shutter mechanism to achieve selective acquisition of effective fundus signals within a compact system structure. The technical principle is that the rolling shutter process essentially creates a time-shifting slit aperture. When the scanning process of this slit is strictly synchronized with the linear confocal illumination, a spatial filtering effect conjugate to the focal point can be achieved at the detection end, effectively suppressing stray light from off-focal planes and retaining only the effective reflected signal from the fundus retinal imaging area. Compared to traditional point-scan confocal methods, this application utilizes a multi-line rolling shutter mechanism to achieve a "virtual aperture" effect, eliminating the need for additional pinhole structures and complex scanning mechanisms. This significantly improves data acquisition efficiency and reduces system complexity while maintaining a high signal-to-noise ratio and image contrast. Figure 1 As shown, the rolling shutter uses a line-by-line scanning and line-by-line exposure method. When all the pixels in the previous line are exposed at the same time, all the pixels in the next line are exposed at the same time, until all lines are exposed.

[0030] The following description, in conjunction with the accompanying drawings, details the fundus imaging system based on line scanning confocal scanning provided in this application through specific embodiments and application scenarios.

[0031] like Figure 2 As shown in the embodiment of this application, a fundus imaging system based on linear confocal scanning is provided. This system may include an illumination unit for generating a linear confocal beam, a scanning unit disposed in the illumination optical path, a beam splitter for separating the illumination optical path from the reflected optical path from the fundus, an imaging lens group, an area array image sensor, and an image processing unit. The beam splitter may be a beam splitter or a dichroic mirror, and the linear scanning direction of the beam splitter is spatially consistent with the camera's rolling shutter direction. Similar to other systems, the beam splitter may also incorporate spatial consistency between the galvanometer scanning direction (linear scanning direction) and the camera's rolling shutter direction; such as synchronously scanning repeatedly from right to left, or repeatedly scanning repeatedly from left to right; or scanning back and forth.

[0032] It is understood that the light source in the embodiments of this application typically employs a single-mode or multi-mode laser diode or a superluminescent diode (SLED) to emit high-brightness, highly directional monochromatic light (such as 830nm near-infrared light for non-invasive retinal imaging). The point beam emitted by the light source first passes through a cylindrical lens. The cylindrical lens's function is to converge or diverge the beam in one direction (e.g., the X-direction), while providing no optical power in the direction perpendicular to it (the Y-direction). Through a carefully designed optical system, the point light source is ultimately "stretched" into a narrow, confocal line beam. This line beam is very thin and bright at the focal plane.

[0033] Exemplarily, the scanning unit is configured to perform one-dimensional scanning on the linear confocal light beam emitted by the illumination unit and project the linear confocal light beam to the fundus region; the linear confocal light beam forms a linear illumination band on the retinal surface after entering the eyeball through the pupil; the imaging lens group is configured to image the fundus information carried by the detection light path after being separated by the light splitting element on the area array image sensor; the area array image sensor works in a rolling shutter mode and receives the image formed by the imaging lens group through a line-by-line exposure manner. The image processing unit is configured to read the image data of the line-by-line exposure of the area array image sensor and reconstruct the time-sequentially continuous line scanning images into a complete two-dimensional fundus image.

[0034] In the rolling shutter mode, the motion trajectory of the effective exposure line on the sensor target surface is synchronized with the scanning trajectory of the linear confocal light beam on the retina, so that at any moment, only the light signal reflected by the illuminated focal plane line region on the retina is received by the corresponding row of pixels on the sensor which is being exposed, thereby realizing the confocal optical slicing effect.

[0035] Exemplarily, the illumination unit comprises a light source and a beam shaping assembly; the beam shaping assembly comprises at least one cylindrical lens configured to shape the light beam emitted by the light source into a linear confocal light beam.

[0036] Exemplarily, the single-line exposure time and the effective row height of the area array image sensor in the rolling shutter mode are matched with the light intensity distribution and scanning speed of the linear confocal light beam on the retinal focal plane, so as to optimize the confocal filtering effect and the image signal-to-noise ratio. The row height of the rolling shutter is determined based on the expected exposure time; the expected exposure time is the exposure time expected by the user in the shooting scene. For example, the single-line pixel readout time is 10us, and the exposure time is 100us, that is, the row height of the actual rolling shutter is 100us / 10us=10 rows of pixels; the larger the row height of the rolling shutter, the worse the confocal effect; according to experience, the experiment is generally kept within 50 rows to ensure the ability of image background noise reduction.

[0037] Optionally, the system further comprises a control unit; the control unit is configured to generate a synchronization control signal and send the synchronization control signal to the scanning unit and the area array image sensor respectively, so that the scanning motion of the scanning unit and the rolling shutter exposure of the area array image sensor are synchronized in time sequence.

[0038] Exemplarily, the control unit is configured to generate a first control signal, a second control signal, and a third control signal; the first control signal is configured to control the illumination unit to generate a linear confocal light beam; the second control signal is configured to control the scanning unit to perform one-dimensional scanning; and the third control signal is configured to control the exposure of the rolling shutter of the area array image sensor.

[0039] The first control signal, the second control signal, and the third control signal are synchronously triggered.

[0040] Exemplarily, as shown in Figure 3 Fig. 1, an imaging schematic diagram of an eye fundus imaging system based on linear scanning confocal provided by an embodiment of the present application is shown. The illumination part of the system uses a linear confocal light beam formed by a cylindrical lens to perform scanning. After entering the eyeball through the pupil, the linear confocal light beam forms a linear illumination band on the surface of the retina. The imaging light path collects the reflected signals of the eye fundus tissue and projects them onto an area array image sensor through an optical imaging system. In the detection part, the rolling shutter characteristic of the area array image sensor is used to form a dynamic slit diaphragm through line-by-line exposure. In order to achieve a filtering effect similar to that of a traditional confocal pinhole, the effective row height of the rolling shutter in this embodiment is set to match the linear height of the illumination light beam at the focal point, so that the motion trajectory of the rolling shutter is strictly synchronized with the scanning trajectory of the illumination light beam. As a result, the sensor only receives the effective reflected signals from the focal plane of the eye fundus, while the stray light from the non-focal plane such as the choroid and the vitreous body is effectively suppressed, thereby significantly improving the signal-to-noise ratio and contrast of the eye fundus image. Through this method, the embodiment realizes the virtualization of the diaphragm function: that is, without additional physical pinholes or slit structures, the rolling shutter of the image sensor is directly used to achieve a conjugate relationship with the focal point. At the same time, relying on the synchronization of illumination and detection, the synchronization relationship between the eye fundus illumination light beam and the sensor detection window in time and space is ensured, thereby realizing the optical sectioning capability of the confocal eye fundus imaging under a compact optical machine structure. Compared with the traditional point scanning confocal eye fundus camera, this embodiment can significantly improve the acquisition efficiency while maintaining high contrast, and reduce the complexity of the system.

[0041] Exemplarily, in order to realize the imaging function as shown in Figure 3 , as shown in Figure 4 , a control signal synchronization schematic diagram provided by an embodiment of the present application is shown. The illumination signal, the galvanometer signal (the galvanometer is one kind of scanning unit), and the camera trigger signal are synchronously triggered, so that the motion trajectory of the effective exposure row of the rolling shutter on the sensor target surface is synchronized with the scanning trajectory of the linear confocal light beam on the retina. Further, at any moment, only the light signals reflected by the illuminated focal plane line area on the retina are received by the corresponding row of pixels on the sensor which are being exposed, thereby realizing the optical sectioning effect of confocal.

[0042] The eye fundus imaging system based on line scanning confocal provided by the embodiment of the application firstly realizes spatial selective collection while maintaining compact optical machine structure through the synchronization of rolling shutter and linear confocal illumination, effectively reduces the interference of non-focal plane scattered light on the image, and obviously improves the contrast and detail resolution of the eye fundus imaging. Secondly, compared with the traditional point scanning confocal mode, the scheme can complete efficient imaging without relying on high-speed two-dimensional scanning mechanism, significantly improves the image acquisition speed, and meets the needs of real-time and large-scale imaging in clinical examination. Thirdly, since the eye fundus reflection signal itself is weak, the scheme of the application has outstanding effect in improving the signal-to-noise ratio, can better display the microstructure such as retinal blood vessels and nerve fiber layer, and is convenient for early detection and diagnosis of lesions. In addition, the system replaces the physical diaphragm with a virtual diaphragm, reduces the use of complex optical elements, reduces the system adjustment difficulty and hardware cost, and provides a possibility for the realization of portable and low-cost eye fundus cameras.

[0043] The eye fundus imaging system based on line scanning confocal provided by the embodiment of the application comprises an illumination unit for generating a linear confocal light beam, a scanning unit arranged in an illumination light path, a light splitting element for separating the illumination light path and the reflection light path from the eye fundus, an imaging lens group, a planar array image sensor, and an image processing unit; the scanning unit is used for one-dimensionally scanning the linear confocal light beam emitted by the illumination unit and projecting it to the eye fundus region; the linear confocal light beam forms a linear illumination band on the retinal surface after entering the eyeball through the pupil; the imaging lens group is used for imaging the eye fundus information carried by the detection light path separated by the light splitting element on the planar array image sensor; the planar array image sensor works in a rolling shutter mode and receives the image formed by the imaging lens group through a line-by-line exposure mode; the image processing unit is used for reading the image data of line-by-line exposure of the planar array image sensor and reconstructing the time-sequentially continuous line scanning images into a complete two-dimensional eye fundus image; wherein the motion trajectory of the effective exposure line of the rolling shutter on the sensor target surface is kept synchronous with the scanning trajectory of the linear confocal light beam on the retina, so that at any moment, only the light signal reflected by the illuminated focal plane line region on the retina is received by the corresponding row of pixels on the sensor which is being exposed, thereby realizing the confocal optical sectioning effect. In this way, by combining the axially widened linear confocal illumination with the camera rolling shutter mechanism, the selective collection of the effective signal of the eye fundus in a compact system structure is realized.

[0044] The eye fundus imaging method based on line scanning confocal provided by the embodiment of the application will be described in detail in combination with the specific embodiments and application scenarios thereof.

[0045] As Figure 5As shown, the embodiment of the present application provides a line-scan confocal-based fundus imaging method, which can include the following steps 501 and 502:

[0046] Step 501, a synchronization control signal is generated, and the scanning motion of the scanning unit of the line-scan confocal-based fundus imaging system and the rolling shutter exposure of the area array image sensor of the line-scan confocal-based fundus imaging system are controlled to be kept synchronous in time sequence based on the synchronization control signal.

[0047] Step 502, the image data exposed line by line by the area array image sensor is read, and the line-scan images synchronous in time sequence are reconstructed into a complete two-dimensional fundus image.

[0048] Specifically, the above-mentioned step 502 can further include the following steps 502a1 and 502a2:

[0049] Step 502a1, a first control signal, a second control signal, and a third control signal are generated.

[0050] Step 502a2, the first control signal is sent to the illumination unit, the second control signal is sent to the scanning unit, and the third control signal is sent to the area array image sensor.

[0051] It should be noted that the above-mentioned steps of the line-scan confocal-based fundus imaging method have been described and explained in detail in the above-mentioned embodiments of the line-scan confocal-based fundus imaging system, and to avoid repetition, will not be repeated here.

[0052] The line-scan confocal-based fundus imaging method provided by the embodiment of the present application firstly generates a synchronization control signal, and controls the scanning motion of the scanning unit of the line-scan confocal-based fundus imaging system and the rolling shutter exposure of the area array image sensor of the line-scan confocal-based fundus imaging system to be kept synchronous in time sequence based on the synchronization control signal; then, the image data exposed line by line by the area array image sensor is read, and the line-scan images synchronous in time sequence are reconstructed into a complete two-dimensional fundus image. In this way, by combining the axially widened line confocal illumination with the camera rolling shutter mechanism, the selective collection of the effective signals of the fundus in a compact system structure is realized.

[0053] It should be noted that the fundus imaging method based on line-scan confocal imaging provided in this application can be executed by a fundus imaging system based on line-scan confocal imaging, or a control unit within that system for executing the method. This application uses the execution of the fundus imaging method based on line-scan confocal imaging by a fundus imaging system as an example to illustrate the fundus imaging method based on line-scan confocal imaging provided in this application.

[0054] It should be noted that, in the embodiments of this application, the fundus imaging methods based on line-scan confocal imaging shown in the accompanying drawings are all illustrated by way of example with reference to one of the accompanying drawings in the embodiments of this application. In specific implementation, the fundus imaging methods based on line-scan confocal imaging shown in the accompanying drawings of the above methods can also be implemented in conjunction with any other accompanying drawings shown in the above embodiments, which will not be elaborated here.

[0055] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6 As shown, the electronic device may include a processor 610, a communications interface 620, a memory 630, and a communication bus 640, wherein the processor 610, communications interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call logic instructions in the memory 630 to execute a fundus imaging method based on linear confocal scanning. This method includes: first, generating a synchronization control signal, and controlling the scanning motion of the scanning unit of the fundus imaging system based on linear confocal scanning to be synchronized with the rolling shutter exposure of the area array image sensor of the fundus imaging system based on linear confocal scanning in time; then, reading the image data exposed line by line by line from the area array image sensor, and reconstructing the sequentially continuous linear scan images into a complete two-dimensional fundus image. Thus, by combining axially broadened linear confocal illumination with the camera rolling shutter mechanism, selective acquisition of effective fundus signals is achieved in a compact system structure.

[0056] Further, the logic instructions in the memory 630 described above can be implemented by software function units and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, and various media that can store program codes.

[0057] In another aspect, the present application also provides a computer program product, which comprises a computer program stored in a computer readable storage medium, and the computer program comprises program instructions, when the program instructions are executed by a computer, the computer can execute the line-scan confocal-based fundus imaging method provided by the above-mentioned methods, which comprises: first, generating a synchronization control signal, and controlling the scanning motion of the scanning unit of the line-scan confocal-based fundus imaging system and the rolling shutter exposure of the area array image sensor of the line-scan confocal-based fundus imaging system to keep synchronization in time sequence based on the synchronization control signal; then, reading the image data exposed line by line by the area array image sensor, and reconstructing the line-scan images in time sequence into a complete two-dimensional fundus image. In this way, by combining the axially widened line confocal illumination with the camera rolling shutter mechanism, the selective collection of the effective signals of the fundus in a compact system structure is realized.

[0058] In another aspect, the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the line-scan confocal-based fundus imaging method provided by the above-mentioned methods, which comprises: first, generating a synchronization control signal, and controlling the scanning motion of the scanning unit of the line-scan confocal-based fundus imaging system and the rolling shutter exposure of the area array image sensor of the line-scan confocal-based fundus imaging system to keep synchronization in time sequence based on the synchronization control signal; then, reading the image data exposed line by line by the area array image sensor, and reconstructing the line-scan images in time sequence into a complete two-dimensional fundus image. In this way, by combining the axially widened line confocal illumination with the camera rolling shutter mechanism, the selective collection of the effective signals of the fundus in a compact system structure is realized.

[0059] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0060] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and necessary general hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of software products, and the computer software products can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and include a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0061] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A fundus imaging system based on linear scanning confocal microscopy, characterized in that, The system includes: an illumination unit for generating a linear confocal beam, a scanning unit disposed in the illumination optical path, a beam splitting element for separating the illumination optical path from the reflected optical path from the fundus, an imaging lens group, an area array image sensor, and an image processing unit. The scanning unit is used to perform one-dimensional scanning of the linear confocal beam emitted by the illumination unit and project it onto the fundus region; the linear confocal beam enters the eyeball through the pupil and forms a linear illumination band on the retinal surface; The imaging lens group is used to image the fundus information carried by the detection optical path after the beam splitting element onto the area array image sensor; The area array image sensor operates in rolling shutter mode and receives the image formed by the imaging lens group through line-by-line exposure. The image processing unit is used to read the image data exposed line by line by the area array image sensor and reconstruct the sequentially continuous line scan images into a complete two-dimensional fundus image; The effective exposure line of the rolling shutter moves on the sensor target surface in sync with the scanning trajectory of the linear confocal beam on the retina, so that at any given moment, only the light signal reflected by the illuminated focal plane line area on the retina is received by the corresponding row of pixels being exposed on the sensor, thereby achieving the optical slicing effect of confocal focusing.

2. The system according to claim 1, characterized in that, The single-line exposure time and effective line height of the area array image sensor in rolling shutter mode are matched with the light intensity distribution and scanning speed of the linear confocal beam at the focal plane of the retina to optimize the confocal filtering effect and image signal-to-noise ratio.

3. The system according to claim 2, characterized in that, The line height of the rolling shutter is determined based on the expected exposure time; the expected exposure time is the exposure time desired by the user in the shooting scenario.

4. The system according to claim 1, characterized in that, The system further includes a control unit; the control unit is used to generate synchronization control signals and send them to the scanning unit and the area array image sensor respectively, so that the scanning motion of the scanning unit and the rolling shutter exposure of the area array image sensor are synchronized in time.

5. The system according to claim 4, characterized in that, The control unit is used to generate a first control signal, a second control signal, and a third control signal; the first control signal is used to control the illumination unit to generate a linear confocal beam. The second control signal is used to control the scanning unit to perform a one-dimensional scan; The third control signal is used to control the exposure of the rolling shutter of the area array image sensor; The first control signal, the second control signal, and the third control signal are triggered synchronously.

6. The system according to claim 1, characterized in that, The scanning direction of the beam splitter is spatially aligned with the camera shutter direction.

7. A fundus imaging method based on linear confocal scanning, characterized in that, The method, applied to the fundus imaging system based on linear confocal scanning as described in any one of claims 1 to 6, comprises: A synchronization control signal is generated, and based on the synchronization control signal, the scanning motion of the scanning unit of the fundus imaging system based on line scanning confocal is controlled to be synchronized with the rolling shutter exposure of the area array image sensor of the fundus imaging system based on line scanning confocal. The image data exposed line by line by the area array image sensor is read, and the sequentially continuous line scan images are reconstructed into a complete two-dimensional fundus image.

8. The method according to claim 7, characterized in that, The process of generating a synchronization control signal and controlling the scanning motion of the scanning unit of the linear confocal fundus imaging system to maintain temporal synchronization with the rolling shutter exposure of the area array image sensor of the linear confocal fundus imaging system based on the synchronization control signal includes: Generate a first control signal, a second control signal, and a third control signal; The first control signal is sent to the illumination unit, the second control signal is sent to the scanning unit, and the third control signal is sent to the area array image sensor.

9. The method according to claim 8, characterized in that, The first control signal is used to control the illumination unit to generate a linear confocal beam; the second control signal is used to control the scanning unit to perform one-dimensional scanning; the third control signal is used to control the exposure of the rolling shutter of the area array image sensor; the first control signal, the second control signal, and the third control signal are triggered synchronously.

10. An electronic device, characterized in that, The system includes a fundus imaging system based on linear confocal scanning as described in any one of claims 1 to 6, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the fundus imaging method based on linear confocal scanning as described in any one of claims 7 to 9.

11. A fundus imaging device based on linear scanning confocal microscopy, characterized in that, The device is applied to the fundus imaging system based on linear confocal scanning as described in any one of claims 1 to 6, the device comprising: The control module is used to generate a synchronization control signal and, based on the synchronization control signal, control the scanning motion of the scanning unit of the fundus imaging system based on linear confocal scanning to keep the rolling shutter exposure of the area array image sensor of the fundus imaging system based on linear confocal scanning in time synchronized. The imaging module is used to read the image data exposed line by line by the area array image sensor and reconstruct the sequentially continuous line scan images into a complete two-dimensional fundus image.

12. The apparatus according to claim 11, characterized in that, The control module is specifically used to generate a first control signal, a second control signal, and a third control signal; The control module is further configured to send the first control signal to the illumination unit, the second control signal to the scanning unit, and the third control signal to the area array image sensor; Wherein, the first control signal is used to control the illumination unit to generate a linear confocal beam; the second control signal is used to control the scanning unit to perform one-dimensional scanning; the third control signal is used to control the exposure of the rolling shutter of the area array image sensor; the first control signal, the second control signal, and the third control signal are triggered synchronously.

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