Imaging system, periscope system, and surgical microscope system

Abstract

This invention provides an imaging system, an external mirror system including the same, a microscope system, and an autofocus method. The imaging system includes an image acquisition device, a control unit, and a calibrator. The image acquisition device includes a variable-focus objective lens and at least one imaging unit, which includes an imaging lens group and a photoelectric converter. The calibrator emits a focusing laser, which illuminates a target area through the variable-focus objective lens. The control unit is configured to adjust the variable-focus objective lens based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving autofocus of the variable-focus objective lens.

Description

Technical Field

[0001] This application relates to the field of medical devices, and more specifically, to an imaging system, an exoscopic system, and a surgical microscope system. Background Technology

[0002] Advances in observation methods have driven the development of neurosurgical medical technology. Good illumination and magnification of the surgical field are fundamental prerequisites for performing precise neurosurgical procedures. With the rapid development of microscopic magnification and illumination technologies, as well as optical instruments and equipment, surgical microscopes and neuroendoscopes have become indispensable display devices and operating platforms for modern neurosurgical microsurgery. Neurosurgical procedures based on microscopes and neuroendoscopes offer advantages such as high surgical precision, good deep illumination, and minimal surgical trauma. However, they also suffer from problems such as shallow depth of field, narrow field of view, short focal length, limited eyepiece movement, restrictive surgeon posture leading to fatigue, large equipment size, and high cost. In recent years, some imaging products have emerged, solving some of the problems of surgical microscopes and neuroendoscopes. However, during surgery, changes in the distance between the target area and the objective lens necessitate constant refocusing, making operation cumbersome. Existing technologies still have many unmet needs in areas such as three-dimensional imaging, autofocus, automatic positioning, and fluorescence fusion.

[0003] To address one or more of the above problems, the present invention provides an imaging system, an exoscopic system, and a surgical microscope system, as well as a corresponding autofocusing method. Summary of the Invention

[0004] In a first aspect, this application provides an imaging system, characterized in that it comprises:

[0005] Image acquisition device, control unit, calibrator;

[0006] The image acquisition device includes a variable focus objective lens and at least one imaging unit, the imaging unit including an imaging lens group and a photoelectric converter;

[0007] The calibrator can emit a focusing laser, which is then directed to the target area via the variable focus objective lens;

[0008] The control unit is configured to adjust the variable focus objective lens based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing of the variable focus objective lens.

[0009] In this application, an image refers to an image captured by an imaging unit, which can be an image on a photoelectric converter or an image further presented on a display or other device.

[0010] Optionally, the direction of the focusing laser light before reaching the variable focus objective is parallel to the optical axis of the variable focus objective.

[0011] Based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area at different focal lengths of the variable focal length objective lens in the image, the focal length adjustment trend is determined, and the focus is continuously adjusted until the position of the light spot in the image reaches the expected position, thereby achieving automatic focusing.

[0012] Optionally, the calibrator emits at least one focusing laser, and the position of the light spot in the image reaches the expected position when the light spot formed by the focusing laser in the target area of ​​the image coincides with the horizontal or vertical center line of the image.

[0013] Optionally, the calibrator emits at least one focusing laser, and the position of the light spot in the image reaching the expected position means that the light spot in the image coincides with the center of the image.

[0014] Optionally, the calibrator emits at least two focusing lasers, and the position of the light spot in the image reaches the expected position when at least two light spots formed by the focusing lasers in the target area in the image coincide.

[0015] In some embodiments, the imaging system of this application further includes a rangefinder, which is used to measure a coarse distance between the variable focus objective and the target area, and the control unit pre-adjusts the variable focus objective based on the coarse distance.

[0016] Furthermore, after autofocus, fine adjustment is also included. The fine adjustment is performed as follows: a focus window is selected in the image, and its sharpness is evaluated by an evaluation function. The fine focus range is determined based on the focal length after autofocus. The sharpness of all images acquired at different focal lengths within the fine focus range is compared, and the focal length corresponding to the image with the best sharpness is selected as the final focal length.

[0017] Optionally, the imaging system of this application also includes an illumination device.

[0018] Optionally, the imaging system of this application further includes a rangefinder connected to an image acquisition device for measuring a coarse distance between the variable focus objective and the target area, and the control unit pre-adjusts the variable focus objective based on the coarse distance.

[0019] Secondly, this application provides an external viewing mirror system, comprising:

[0020] The components include a trolley, a robotic arm, an imaging system, and input / output devices. The imaging system comprises an image acquisition device, a control unit, and a calibrator.

[0021] The first end of the robotic arm is connected to a fixed structure or the trolley, and the second end of the robotic arm is connected to an image acquisition device.

[0022] The image acquisition device includes a variable focus objective lens and at least one imaging unit, the imaging unit including a photoelectric converter;

[0023] The calibrator can emit a focusing laser, which is then directed to the target area via the variable focus objective lens;

[0024] The control unit is configured to adjust the variable focus objective lens based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing.

[0025] Input / output devices include one or more of the following: displays (e.g., 3D displays, touch screens), mice, keyboards, microphones, cameras for gesture input, foot switches, etc.

[0026] Furthermore, in the external viewing mirror system of the present invention, the direction of the focusing laser light before reaching the variable focus objective is parallel to the optical axis of the variable focus objective.

[0027] Optionally, in the external viewing mirror system of the present invention, the trolley may be equipped with a memory and a processor; the memory is used to store program code and data, and the processor is used to call the program code;

[0028] Optionally, in the external viewing mirror system of the present invention, the control unit may be set separately, such as an embedded system; or it may be integrated into the processor; or it may be connected in communication with the processor to receive and execute the processor's instructions, such as a microcontroller; the control unit or processor is connected in communication with the photoelectric converter to receive image signals and process and analyze them to complete automatic focusing.

[0029] In the external viewing mirror system of the present invention, the automatic focusing includes preliminary focusing, which adjusts the focal length of the variable focus objective lens based on the positional relationship of the light spot formed by the focusing laser in the target area until the focal length of the variable focus objective lens falls in the target area, thus completing the preliminary focusing.

[0030] Optionally, the external viewing mirror system of the present invention further includes an illumination device.

[0031] Optionally, the external viewing mirror system of the present invention further includes a rangefinder connected to an image acquisition device for measuring the coarse distance between the variable focus objective and the target area. The control unit performs pre-coarse adjustment on the variable focus objective based on the coarse distance, so that the focus spot is clearly visible in the image.

[0032] Optionally, in the external viewing mirror system of the present invention, the autofocus further includes a pre-adjustment step before the initial focusing. In the pre-adjustment step, the coarse distance between the target area and the variable focus objective is first measured, and then the focal length of the variable focus objective of the image acquisition device is adjusted according to the coarse distance so that the focus spot is clearly visible in the image.

[0033] Optionally, the external mirror system of the present invention further includes fine adjustment after autofocus. The fine adjustment is performed as follows: a focus window is selected in the image, and its sharpness is evaluated by an evaluation function. The fine focus range is determined based on the focal length after autofocus. The sharpness of all images acquired at different focal lengths within the fine focus range is compared, and the focal length corresponding to the image with the best sharpness is selected as the final focal length.

[0034] Optionally, in the external viewing mirror system of the present invention, the image acquisition device includes at least two imaging units that can generate 3D images; further, the image acquisition device includes at least one fluorescence imaging unit.

[0035] In some embodiments, the external viewing mirror system of the present invention further includes a positioning and guiding device; further, it may also include a second joint support arm, the first end of the second joint support arm being connected to a trolley or a fixed structure, and the second end being connected to the positioning and guiding device.

[0036] Optionally, the positioning guidance device is a structured light camera, a stereo camera, or a depth camera. In some embodiments, the structured light camera includes a projection module and a camera module.

[0037] In the external viewing mirror system of the present invention, scene information can be obtained through the positioning and guidance device to determine the specific positions of the image acquisition device and the target part. Through the movement of the robotic arm and / or the trolley, the image acquisition device is positioned within the working distance range relative to the target part.

[0038] The positioning and guidance device can also sense the image acquisition device and its surrounding environment during the operation, reminding or preventing accidental contact, thus enhancing intraoperative safety.

[0039] Thirdly, the present invention provides a microscope system that includes the imaging system of the first aspect.

[0040] Fourthly, the present invention provides an automatic focusing method for an imaging system, wherein the imaging system is equipped with a calibrator, and the focal length of the variable focal length objective lens is adjusted based on the position of the light spot generated by the focusing laser emitted by the calibrator in the target area in the image until the position of the light spot in the image reaches a specified position to achieve automatic focusing.

[0041] Optionally, the autofocus method of the present invention further includes a pre-adjustment step, in which a ranging laser is used to obtain a coarse distance between the target area and the objective lens, and the focal length of the variable focal length objective lens of the image acquisition device is adjusted based on the coarse distance so that the focus spot is clearly visible in the image.

[0042] Optionally, the autofocus method of the present invention further includes fine adjustment, which is performed as follows: a focus window is selected in the image, and its sharpness is evaluated by an evaluation function. The fine focus range is determined based on the focal length after autofocus, and the sharpness of all images acquired at different distances within the fine focus range is compared. The focal length corresponding to the image with the best sharpness is selected as the final focal length.

[0043] The advantages of the method of the present invention are not limited to the following:

[0044] 1. It can quickly focus at any time before and during the operation. Automatic focusing avoids the tedious operation of manual focusing and saves surgical time.

[0045] 2. During the operation, if the target area changes shape as the surgery progresses, resulting in loss of focus, it can be quickly corrected by autofocus to ensure continuous image clarity.

[0046] 3. The rangefinder can further narrow the focus adjustment range and shorten the autofocus time;

[0047] 4. Fine-tuning ensures the clearest imaging effect. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the imaging system of this application;

[0050] Figure 2 This is one of the schematic diagrams of the autofocus method of the present invention;

[0051] Figure 3 Another schematic diagram of the autofocus method of the present invention is shown;

[0052] Figure 4 The position of the focusing laser on the same plane at different focal lengths is shown in the autofocus method of the present invention;

[0053] Figure 5Another schematic diagram of the autofocus method of the present invention is shown;

[0054] Figure 6 for Figure 1 The diagram shows the structure of the external viewing mirror system.

[0055] Figure 7 This is a schematic diagram of another component structure of the imaging system of the present invention;

[0056] Figure 8 This is a schematic diagram of another component structure of the imaging system of the present invention;

[0057] Figure 9 A schematic diagram of an external viewing mirror system provided in another embodiment of this application;

[0058] icon:

[0059] 100 - Cart; 200 - Robotic arm; 300 - Image acquisition device; 400 - Input / output device (touch screen). Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] Example 1

[0062] See Figure 1 This invention designs an imaging system, including an image acquisition device, a control unit, and a calibrator.

[0063] The image acquisition device includes a variable focus objective lens and at least one imaging unit, the imaging unit including a photoelectric converter;

[0064] The calibrator can emit a focusing laser, which is then directed to the target area via a variable-focus objective lens;

[0065] The control unit is configured to adjust the variable focus objective based on the position of the spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing of the variable focus objective.

[0066] For example, the image acquisition device includes a variable-focus objective lens and a visible light imaging unit; another example is that the image acquisition device includes a variable-focus objective lens and two visible light imaging units; yet another example is that the image acquisition device includes a variable-focus objective lens, two visible light imaging units, and a fluorescence imaging unit; yet another example is that the image acquisition device includes a variable-focus objective lens, two visible light imaging units, and two fluorescence imaging units. Those skilled in the art will understand that the two visible light imaging units and the two fluorescence imaging units can generate corresponding 3D images; the fluorescence image can be superimposed on the visible light image. The variable-focus objective lens of the present invention includes multiple lenses, and its focal length is changed by adjusting the position of at least some of the lenses. In some examples, the imaging unit may also include a zoom lens assembly, which can achieve continuous zoom.

[0067] The calibrator includes one or more calibration components, each containing a calibration light source that emits a focusing laser. The focusing laser is directed to the target area via a variable-focus objective lens of the image acquisition device. The direction of the focusing laser when it reaches the variable-focus objective lens is parallel to the optical axis of the variable-focus objective lens. It can be understood that when the calibrator includes multiple calibration components, only some of the calibration components can be used to emit the required number of focusing lasers, such as one, two, three, eight, etc.

[0068] The control unit adjusts the variable focus objective lens based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing of the variable focus objective lens.

[0069] The control unit can be set up independently, such as in an embedded system; of course, the control unit can also be controlled by a host computer through communication. The control unit is connected to the photoelectric converter to receive image signals and process and analyze them. The control unit is also connected to the focusing structure (such as the objective lens drive motor) to adjust the focal length of the variable focus objective lens.

[0070] Optionally, the calibrator includes a calibration component that emits a focusing laser parallel to the optical axis of the variable-focus objective. This laser, after passing through the variable-focus objective, illuminates the target area, forming a light spot. The imaging unit captures an image of the target area containing this light spot. The position of the light spot in the image differs under different focusing conditions, and the control unit adjusts the variable-focus objective accordingly to achieve automatic focusing. See also Figure 2The diagonal dashed lines represent the positions of the light spot in the image under different focusing states. When focusing is achieved, the light spot coincides with the image centerline. The image centerline is only for illustration and does not necessarily need to be displayed in practice. It can be understood that the dashed line can be any straight line passing through the center, not limited to a diagonal line; that is, the focusing laser can have multiple position settings. The image centerline can be a horizontal or vertical centerline, depending on the setting position of the calibration component. Furthermore, the image can be divided into four quadrants or a coordinate system can be set. The focusing direction can be determined by the position of the light spot in the image, for example, by referring to... Figure 3 In one example, a calibrator is positioned at the upper left of the image acquisition device (lens) to emit a laser. The laser beam forms a spot within the field of view of the image acquisition device, dividing the acquired image into sections. Figure 3 As shown in the four quadrants, if the light spot is located in the second quadrant of the image, the focal length needs to be reduced. This is achieved by adjusting the objective lens through the control unit until the light spot is centered in the image, thus achieving focus. If the light spot is located in the fourth quadrant, the focal length needs to be increased. This is achieved by adjusting the objective lens through the control unit until the light spot is centered in the image, thus achieving focus. Conversely, in another example, a calibrator is located on the lower right side of the image acquisition device (lens) to emit a laser. The laser forms a light spot within the field of view of the image acquisition device, dividing the acquired image into quadrants. Figure 3 As shown in the diagram, if the light spot is located in the second quadrant of the image, the focal length needs to be increased. This is achieved by adjusting the objective lens through the control unit until the light spot is centered in the image, thus achieving focus. If the light spot is located in the fourth quadrant, the focal length needs to be decreased. This is also achieved by adjusting the objective lens through the control unit until the light spot is centered in the image, thus achieving focus. It can be understood that dividing the image into four equal quadrants is equivalent to a coordinate system, where the origin of the coordinate system can be set at any location in the image, such as the image center, a vertex, or a fixed point.

[0071] Optionally, the calibrator includes two calibration components, see [link to documentation]. Figure 5 and Figure 3In one example, two calibration components are located on the left side of the image acquisition device. When out of focus, the two light spots are located in the left quadrant (second and third quadrants) of the image. The focus needs to be adjusted in the first direction until the two light spots overlap to achieve autofocus. When over-focus, the two light spots are located in the right quadrant (first and fourth quadrants) of the image. The focus needs to be adjusted in the second direction to achieve autofocus. Conversely, in another example, the two calibration components are located on the right side of the image acquisition device. When out of focus, the two light spots are located in the left quadrant (second and third quadrants) of the image. The focus needs to be adjusted in the first direction until the two light spots overlap to achieve autofocus. When over-focus, the two light spots are located in the right quadrant (first and fourth quadrants) of the image. The focus needs to be adjusted in the second direction to achieve autofocus.

[0072] In summary, the position of the calibrator relative to the image acquisition device is determinable. At this point, the correspondence between the "position of the light spot in the image" and the "defocus / focus / overfocus state of the variable focus objective" is determinable, and the focusing direction can be determined accordingly.

[0073] Example 2

[0074] refer to Figure 1 This example is described based on Example 1, but the difference between it and Example 1 is that the external viewing mirror system can also be equipped with a laser rangefinder.

[0075] A laser rangefinder can obtain a coarse distance between a variable-focus objective lens and the target area (the area to be operated on). Then, based on the coarse distance, the focal position of the variable-focus objective lens can be determined, thus ensuring that the depth of field of the variable-focus objective lens covers the coarse measurement error range, making the spot of the focusing laser clearly visible in the image. The laser rangefinder can further accelerate the focusing speed and reduce the focusing time.

[0076] Example 3

[0077] The present invention also provides an autofocusing external mirror system, see reference. Figure 6 It includes: a trolley 100, a robotic arm 200, an imaging system 300, and an input / output device 400, wherein the imaging system 300 includes an image acquisition device, a control unit, and a calibrator, and the specific structure is as described in Example 1.

[0078] The first end of the robotic arm 200 can be connected to the trolley 100 or to a fixed structure, such as an operating table, the ground, a wall, or a ceiling. The second end of the robotic arm 200 is connected to the image acquisition device. The robotic arm 200 can have 6, 7, or more joints, enabling at least 6 degrees of freedom of movement and flexibly adjusting the position and angle of the image acquisition device. In some examples, sensors are provided at the joints of the robotic arm 200 to precisely control the position of the image acquisition device connected to its end. Various types of sensors can be used, such as angle sensors, force sensors, and position sensors. A separate force sensor can also be added to the end of the robotic arm 200 to increase the control accuracy of the image acquisition device 300. Preferably, the force sensor is a six-dimensional force sensor.

[0079] Example 4:

[0080] refer to Figure 7 This example is described based on any of the foregoing embodiments, except that the external viewing mirror system is also provided with a fluorescent optical path component.

[0081] The fluorescence optical path assembly includes a beam splitter, a fluorescence filter, an imaging lens group, and a photoelectric converter. By irradiating the target area with a specific wavelength, fluorescence can be generated. After passing through a variable focus objective lens and the fluorescence optical path, the fluorescence reaches the photoelectric converter (e.g., a black and white camera or a color camera), generating a fluorescence image. The fluorescence image can be superimposed with the visible light image, thereby superimposing the information of the fluorescence image (e.g., vascular structure) with the information of the visible light image, which helps doctors obtain richer structural information.

[0082] The fluorescent optical path assembly can also consist of two sets, thereby forming a three-dimensional fluorescent image, see [link to documentation]. Figure 8 Two fluorescent images can be combined to form a stereoscopic fluorescent image, and two visible light images can be combined to form a stereoscopic visible light image. The two can then be combined to form a superimposed stereoscopic fluorescent and visible light image. Alternatively, the fluorescent image can be superimposed with a visible light image from the same optical path, and then combined with a superimposed image from another optical path to generate a three-dimensional image.

[0083] Example 5

[0084] See Figure 6 , Figure 6 An embodiment of an exoscopic system for imaging a surgical site is schematically illustrated, comprising:

[0085] The trolley 100 is equipped with a memory and processor, input / output devices including a display 400, and foot switch, keyboard, mouse, microphone, etc. (not shown). The trolley can be moved to the required position and fixed. The display is preferably a 3D display.

[0086] 200 robotic arms

[0087] Image acquisition device 300, it is understood, may also include an illumination device and / or a rangefinder;

[0088] The first end of the robotic arm 200 is connected to the trolley, and the second end is connected to the image acquisition device 300 via an adapter.

[0089] The robotic arm 200 has multiple articulated arms and joints, and multiple degrees of freedom, such as 4, 5, 6, or 7 degrees of freedom, preferably at least 6 degrees of freedom; the end of the robotic arm 200 can be equipped with a force sensor (e.g., a six-dimensional force sensor), and each joint can also be equipped with a force sensor.

[0090] The processor can control the robotic arm 200 according to one of the following modes via a corresponding control unit:

[0091] -Automatic mode

[0092] - Collaboration mode

[0093] In automatic mode, the processor automatically calculates the motion trajectory between the current position of the robotic arm 200 and the position set point, and moves the robotic arm 200 from its current position and orientation to the position set point and orientation set point through the control circuit, thereby moving the image acquisition device to the preset position.

[0094] In collaborative mode, control circuitry assists the robotic arm 200 to move in the direction of a force applied by the operator. This force can be applied to the image acquisition device or an axis of the robotic arm 200, and is measured and calculated using one or more sensors mounted on the end of the robotic arm 200 and / or each of its axes. Geometric constraints can be integrated into collaborative mode to limit the movement of the robotic arm 200, thus contributing to improved safety in medical procedures. For example, movement can be constrained to be within a region, outside a region, along an axis or curve, around a point, etc. These constraints can be defined by any type of geometry and associated behavior. In collaborative mode, control circuitry assists the operator in positioning the image acquisition device to a preset location and orientation. In short, by dragging the end of the articulated support arm or the image acquisition device connected to it, the articulated support arm can assist in movement based on the magnitude and direction of the force, allowing the end of the articulated support arm or the image acquisition device to move to the desired position.

[0095] The image acquisition device includes a variable focus objective lens and two imaging units. Each imaging unit includes a focusing lens group and a photoelectric converter (e.g., a black and white camera or a color camera). In some instances, the imaging unit may also include a zoom lens group.

[0096] The calibrator includes one or more calibration components, each containing a calibration light source capable of emitting a focusing laser. The focusing laser is directed onto the target area via the variable focus objective lens. Based on the positional relationship of the light spot generated by the focusing laser in the target area, the variable focus objective lens is adjusted by the control unit to change its focal length, thereby achieving automatic focusing.

[0097] Example 6:

[0098] refer to Figure 9 This example is described based on Embodiment 5, except that the first end of the robotic arm 200 is fixedly connected to the ceiling of the operating room. The robotic arm 200 has a larger range of motion and more joints. The trolley is communicatively connected to the control unit of the robotic arm, and can be retracted and placed near the ceiling when not in use. It is understood that the first end of the robotic arm 200 can also be connected to the wall of the operating room or a hospital bed; both are solutions of this invention.

[0099] Example 7

[0100] The present invention also provides a surgical microscope system comprising the imaging system described in Examples 1 to 3, and a conventional surgical microscope stand and eyepiece.

[0101] Example 8

[0102] An autofocus method for the imaging system of the present invention adjusts the focal length of the variable focal length objective lens based on the position of the light spot generated by the focusing laser emitted by the calibrator in the target area in the image until the position of the light spot in the image reaches a specified position, thereby achieving autofocus.

[0103] Example 9

[0104] Another autofocusing method for the external mirror of the present invention is described based on embodiment 8, and further includes a pre-adjustment step. In the pre-adjustment step, a ranging laser is used to obtain a coarse distance between the target area and the objective lens, and the focal length of the objective lens of the image acquisition device is roughly adjusted based on the coarse distance.

[0105] Example 10

[0106] Another autofocus method for the external mirror of the present invention, described based on Embodiment 8, further includes fine adjustment, which is performed as follows: a focus window is selected in the image, and the center region of the image is selected as the focus window using the central region method. Then, a convolution operation is performed on the image within the focus window using operators such as the Sobel operator or the Roberts operator, so that each pixel obtains a new grayscale value. To increase the grayscale difference, a square operation is performed. Finally, the average of all grayscale values ​​within the window is calculated, and the obtained value is the final result of the evaluation function. The larger the value, the clearer the image. The fine focus range for the next step is determined based on the focal length after focusing in the aforementioned embodiment. The sharpness of all images acquired at different distances within the fine focus range is compared, and the focal length corresponding to the image with the best sharpness is selected as the final focal length. The focus window can be any proportion of the image, such as one-quarter, one-third, one-half, etc.

[0107] Example 11

[0108] Another autofocus method for the imaging system of the present invention includes the pre-adjustment step of Embodiment 9, the autofocus step of Embodiment 8, and the fine adjustment step of Embodiment 10, thereby achieving fast and fine autofocus.

[0109] The features described in the various embodiments of this specification can be substituted for or combined with each other. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.

[0110] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An imaging system, characterized by, include: Image acquisition device, control unit, calibrator; The image acquisition device includes a variable focus objective lens and at least one imaging unit, the imaging unit including an imaging lens group and a photoelectric converter; The calibrator can emit a focusing laser, which is then directed to the target area via the variable focus objective lens; The control unit is configured to adjust the variable focus objective lens based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing of the variable focus objective lens.

2. The imaging system of claim 1, wherein, The direction of the focusing laser light before it reaches the variable focus objective is parallel to the optical axis of the variable focus objective.

3. The imaging system of claim 1, wherein, Based on the position of the light spot formed by the focusing laser emitted by the calibrator in the target area at different focal lengths of the variable focal length objective lens in the image, the focal length adjustment trend is determined, and the focus is continuously adjusted until the position of the light spot in the image reaches the expected position, thereby achieving automatic focusing.

4. The imaging system of claim 3, wherein, The calibrator emits at least one focusing laser, and the position of the light spot in the image reaches the expected position when the light spot in the image coincides with the horizontal or vertical center line of the image.

5. The imaging system of claim 3, wherein, The calibrator emits at least one focusing laser, and the position of the light spot in the image reaching the expected position means that the light spot in the image coincides with the center of the image.

6. The imaging system of claim 3, wherein, The calibrator emits at least two focusing lasers, and the position of the light spot in the image reaches the expected position when at least two light spots formed by the focusing laser in the target area in the image coincide.

7. The imaging system of any one of claims 1 to 6, wherein, It also includes a rangefinder, which is used to measure the coarse distance between the variable focus objective and the target area, and the control unit pre-adjusts the variable focus objective based on the coarse distance.

8. The imaging system of claim 1, wherein, The control unit also performs fine adjustment, which is carried out as follows: a focus window is selected in the image, and its sharpness is evaluated by an evaluation function. The fine focus range is determined based on the focal length after autofocus. The sharpness of all images acquired at different focal lengths within the fine focus range is compared, and the focal length corresponding to the image with the best sharpness is selected as the final focal length.

9. The imaging system of claim 1, wherein, The image acquisition device includes at least two imaging units and can generate 3D images.

10. The imaging system of claim 1, wherein, The image acquisition device includes at least one fluorescence imaging unit.

11. The imaging system of claim 1, wherein, It also includes lighting fixtures.

12. A microscope system, characterized by The imaging system included in any one of claims 1 to 11.

13. An exterior mirror system, characterized in that The imaging system included in any one of claims 1 to 11.

14. An autofocusing method of an imaging system, characterized by, The imaging system is equipped with a calibrator, which adjusts the focal length of the variable focus objective lens based on the position of the light spot generated by the focusing laser emitted by the calibrator in the target area in the image, thereby achieving automatic focusing. The focusing laser is parallel to the optical axis of the variable focus objective lens before reaching it.

15. The autofocusing method of claim 14, wherein, It also includes a pre-adjustment step, in which a ranging laser is used to obtain a coarse distance between the target area and the objective lens, and the variable focal length objective lens of the image acquisition device is coarsely adjusted based on the coarse distance.

16. The autofocusing method of claim 14, wherein, It also includes fine-tuning, which is performed as follows: a focus window is selected in the image, and its sharpness is evaluated by an evaluation function. The fine-tuning range is determined based on the focal length after autofocus. The sharpness of all images acquired at different focal lengths within the fine-tuning range is compared, and the focal length corresponding to the image with the best sharpness is selected as the final focal length.

Images