Imaging system, and exterior mirror system and surgical microscope system comprising same

Abstract

The invention provides an imaging system, an exterior mirror system comprising the same, an operating microscope system and an automatic focusing method, the imaging system comprises an image acquisition device, a control unit and a calibrator, the image acquisition device comprises a variable-focus objective lens and at least one imaging unit, and the imaging unit comprises an imaging lens group and a photoelectric converter; the calibrator can emit focusing laser, and the focusing laser is irradiated to a target area through the variable-focus objective lens; and the control unit is configured to adjust the variable-focus objective lens based on the position of a light spot formed by the focusing laser emitted by the calibrator in the target area in the image so as to realize automatic focusing of the variable-focus objective lens.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and more specifically, to an imaging system and an exoscopic system and a surgical microscope system comprising the same. Background Art

[0002] The advancement of observation methods has promoted the development of neurosurgery medical technology. Good illumination and magnification of the surgical field area is the basic prerequisite for completing precise neurosurgery. With the rapid development of microscopic magnification and lighting technology and optical instruments and equipment, surgical microscopes and neuroendoscopes have become indispensable display devices and operating platforms for contemporary neurosurgery microsurgery. Neurosurgery based on microscopes and neuroendoscopes has the advantages of high surgical operation accuracy, good deep illumination, and small surgical trauma, but it also has problems such as shallow depth of field, narrow field of view, short focal length, limited eyepiece movement, limited operator posture and easy fatigue, large equipment size, and high price. In recent years, some surgical imaging products have appeared, which have solved some problems of surgical microscopes and neuroendoscopes. However, during the operation, the distance between the target area and the objective lens changes, resulting in the need for continuous focusing, which is cumbersome to use. The existing technology still has many needs to be solved in many aspects such as three-dimensional imaging, autofocus, automatic positioning, and fluorescence fusion.

[0003] In order to solve one or more of the above problems, the present invention provides an imaging system, an exoscopic system, a surgical microscope system, and a corresponding autofocus method. Summary of the invention

[0004] In a first aspect, the present application provides an imaging system, characterized in that it includes:

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

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

[0007] The calibration instrument can emit a focusing laser, and the focusing laser is irradiated to a target area through 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 to achieve focusing of the variable-focus objective lens.

[0009] Optionally, a light direction of the focusing laser before reaching the variable-focus objective lens is parallel to an optical axis of the variable-focus objective lens.

[0010] In the imaging system of the present application, the calibration instrument emits two or more focusing lasers, and the focus adjustment trend is determined according to the change in the spacing of the light spots formed by the focusing lasers emitted by the calibration instrument in the target area when the variable focus objective lens is at different focal lengths, and the focus is adjusted continuously until the positions of the light spots overlap, thereby achieving automatic focusing. Furthermore, the position overlap of the light spots refers to the overlap of the centroids of the light spots or any specified feature points.

[0011] Optionally, the positional overlap of the light spots is determined by visually inspecting the target area.

[0012] Optionally, the overlap of the light spot positions means that the system automatically determines the overlap of the light spot positions in the image to achieve autofocus. In this application, the image refers to the image captured by the imaging unit, which can be an image on the photoelectric converter or an image further presented on a display or other device.

[0013] In some embodiments, the imaging system of the present application also includes a rangefinder, which is used to measure a rough distance between the variable-focus objective lens and the target area, and the control unit pre-adjusts the variable-focus objective lens based on the rough distance, that is, changes the focal length of the variable-focus objective lens.

[0014] Furthermore, the autofocus also includes fine adjustment, which is performed as follows: a focus window is selected in the image, and then its clarity is evaluated through an evaluation function, and based on the preliminary focus, the clarity of all images acquired at different focal lengths within a preset range is compared, and the focal length with the best clarity is selected as the final focal length.

[0015] Optionally, the imaging system of the present application further includes a lighting device.

[0016] In a second aspect, the present application provides an exterior mirror system, comprising:

[0017] Trolley, robotic arm, imaging system, input and output equipment, wherein the imaging system includes an image acquisition device, a control unit, and a calibrator,

[0018] The first end of the mechanical arm is connected to the fixed structure or the trolley, and the second end of the mechanical arm is connected to the image acquisition device;

[0019] The image acquisition device includes a variable focus objective lens and at least one imaging unit, and the imaging unit includes a photoelectric converter;

[0020] The calibration instrument can emit a focusing laser, and the focusing laser is irradiated to a target area through the variable-focus objective lens;

[0021] 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 to achieve focusing.

[0022] Input and output devices include one or more of the following: display (such as 3D display, touch screen), mouse, keyboard, microphone, camera for gesture input, foot switch, etc.

[0023] Furthermore, in the exterior mirror system of the present invention, the direction of the light of the focusing laser before reaching the variable-focus objective lens is parallel to the optical axis of the variable-focus objective lens.

[0024] Optionally, in the exterior mirror system of the present invention, the trolley may be provided with a memory and a processor; the memory is used to store program codes and data, and the processor is used to call the program codes;

[0025] Optionally, in the exterior mirror system of the present invention, the control unit can be separately provided, such as an embedded system, etc.; it can also be integrated in the processor; or it can be communicated with the processor to receive and execute instructions of the processor, such as a single-chip microcomputer, etc.; the control unit or the processor can be communicated with the photoelectric converter to receive the image signal and process and analyze it to complete automatic focusing.

[0026] Optionally, the exterior mirror system of the present invention further includes a lighting device.

[0027] Optionally, the exterior mirror system of the present invention further includes a rangefinder, which is connected to the image acquisition device and is used to measure a rough distance between the variable-focus objective lens and the target area, and the control unit pre-adjusts the variable-focus objective lens based on the rough distance.

[0028] Optionally, in the exterior mirror system of the present invention, the autofocus also includes a pre-adjustment step before the initial focusing, in which a rough distance between the target area and the variable-focus objective lens is first measured, and then the focal length of the variable-focus objective lens of the image acquisition device is adjusted according to the rough distance.

[0029] Optionally, in the exterior mirror system of the present invention, the control unit also performs fine adjustment, and the fine adjustment is performed as follows: a focus window is selected in the image, and then its clarity is evaluated by an evaluation function, a fine focus range is determined based on the focal length after autofocusing, and a clarity comparison is performed on images acquired at all different focal lengths within the fine focus range, and the focal length with the best clarity is selected as the final focal length.

[0030] Optionally, in the exoscopic system of the present invention, the image acquisition device includes at least two imaging units, which can generate a 3D image; further, the image acquisition device includes at least one fluorescent imaging unit.

[0031] In some embodiments, the exterior mirror system of the present invention also includes a positioning guide device; further, it may also include a second joint support arm, the first end of the second joint support arm is connected to the trolley or the fixed structure, and the second end is connected to the positioning guide device.

[0032] Optionally, the positioning guiding 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.

[0033] In the exterior mirror system of the present invention, scene information can be acquired through the positioning and guiding device to determine the specific positions of the image acquisition device and the target part, and the image acquisition device can be positioned within the working distance range relative to the target part through the movement of the robotic arm and / or the trolley.

[0034] The positioning guidance device can also sense the image acquisition device and its surrounding environment during surgery, remind or prevent accidental collisions, etc., to enhance safety during surgery.

[0035] In a third aspect, the present invention provides a microscope system, which comprises the imaging system of the first aspect, a microscope stand, and an eyepiece. When the microscope moves to a suitable position, the imaging system automatically focuses.

[0036] In a fourth aspect, the present invention provides an automatic focusing method for an imaging system, wherein the imaging system is provided with a calibrator, and the focus of a variable-focus objective lens is adjusted based on the position of a light spot generated by a focusing laser emitted by the calibrator in a target area until the position of the light spot in the image reaches a specified position to achieve automatic focusing.

[0037] Optionally, the autofocus method of the present invention further comprises a pre-adjustment step, in which a distance measuring laser is used to obtain a rough distance between the target area and the objective lens, and the focal length of the variable focus objective lens of the image acquisition device is adjusted based on the rough distance.

[0038] Optionally, the autofocus method of the present invention also includes fine adjustment, which is performed as follows: a focus window is selected in the image, and then its clarity is evaluated by an evaluation function, a fine focus range is determined based on the focal length after autofocusing, and a clarity comparison is performed on images acquired at all different distances within the fine focus range, and the focal length with the best clarity is selected as the final focal length.

[0039] The advantages of the method of the present invention are not limited to the following:

[0040] 1. Rapid focusing can be performed at any time before and during surgery, saving surgical time;

[0041] 2. During the operation, if the focus is lost due to the morphological changes of the target area during the operation, it can be quickly corrected by focusing to ensure the continuous clarity of the image;

[0042] 3. The rangefinder can further narrow the focus adjustment range and shorten the autofocus time;

[0043] 4. Fine adjustment ensures the clearest imaging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of the structure of the imaging system of the present application;

[0046] Figure 2 One of the principle diagrams of the automatic focusing method of the present invention;

[0047] Figure 3 The second schematic diagram of the automatic focusing method of the present invention is shown;

[0048] Figure 4 The third schematic diagram of the automatic focusing method of the present invention is shown;

[0049] Figure 5 is a structural schematic diagram of an exterior mirror system;

[0050] Figure 6 is a schematic diagram of another composition structure of the imaging system of the present invention;

[0051] Figure 7 is a schematic diagram of another composition structure of the imaging system of the present invention;

[0052] Figure 8 A schematic diagram of an exterior mirror system provided in another embodiment of the present application;

[0053] icon:

[0054] 100 - trolley; 200 - robotic arm; 300 - image acquisition device; 400 - input and output device (touch screen). DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] Example 1

[0057] See also Figure 1 The present invention designs an imaging system, including an image acquisition device, a control unit, and a calibration instrument.

[0058] The image acquisition device includes a variable focus objective lens and at least one imaging unit, and the imaging unit includes a photoelectric converter;

[0059] The calibrator can emit a focusing laser, which is irradiated to the target area through a variable-focus objective lens;

[0060] 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 to achieve focusing of the variable-focus objective lens.

[0061] For example, the image acquisition device includes a variable focus objective lens and a visible light imaging unit. For another example, the image acquisition device includes a variable focus objective lens and two visible light imaging units. For another example, the image acquisition device includes a variable focus objective lens, two visible light imaging units, and a fluorescent imaging unit. For another example, the image acquisition device includes a variable focus objective lens, two visible light imaging units, and two fluorescent imaging units. It is understood by those skilled in the art that two visible light imaging units and two fluorescent imaging units can produce corresponding 3D images; the fluorescent image can be superimposed on the visible light image. The variable focus objective lens of the present invention includes a plurality of lenses, and the focal length thereof is changed by adjusting the position of at least part of the lenses. In some instances, the imaging unit may also include a zoom lens assembly, which can achieve continuous zooming.

[0062] The calibrator includes one or more calibration components, the calibration components include a calibration light source, and can emit a focus laser, the focus laser is irradiated to the target area through the variable focus objective lens of the image acquisition device, and the direction of the focus laser when reaching 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 focus lasers, such as one, two, three, eight, etc.;

[0063] The user or 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 to achieve the focusing of the variable-focus objective lens.

[0064] The control unit can be set up separately, such as an embedded system; of course, the control unit can also be controlled by the host computer communication; the control unit is connected to the photoelectric converter for communication, receives the image signal and processes and analyzes it, and the control unit is also connected to the focusing structure (such as the objective lens drive motor) for adjusting the focal length of the variable focus objective lens.

[0065] Optionally, the calibrator includes a calibration component, which emits a focusing laser parallel to the optical axis of the variable-focus objective lens. The focusing laser passes through the variable-focus objective lens and then irradiates the target area to form a light spot. Under different focusing states, the position of the light spot is different. The control unit adjusts the variable-focus objective lens accordingly to achieve automatic focusing of the variable-focus objective lens.

[0066] See also Figure 2 At the first focal length, the calibrator emits two focusing lasers to form two light spots A and B. The focus is adjusted monotonically to reach the second focal length. The position of the light spots changes and moves to A' and B'. The distance between the two light spots becomes shorter, indicating that the focusing direction is correct. Continue to adjust along the previous adjustment direction until the two light spots coincide, that is, focusing is achieved; conversely, if the two light spots at the first focal length are located at A' and B', and the two light spots at the second focal length are located at A and B, it means that the focus adjustment direction is wrong and needs to be adjusted in the opposite direction until the two light spots coincide to achieve focusing.

[0067] It is understood that the two focusing lasers can be arranged in a variety of ways, and can be arranged symmetrically or asymmetrically, see Figure 3 , set on one side of the vertical axis of the field of view / image, and two focusing lasers symmetrically distributed on the horizontal axis of the field of view / image, when the focal lengths are different, the light spot positions in the field of view / image are superimposed to form a track, as shown by the crossed dotted lines. When the two light spots overlap, focusing is achieved.

[0068] The number of focusing lasers can also be 3 or more, see Figure 4 , at the first focal length, the calibrator emits 4 focusing lasers, forming 4 light spots A, B, C, and D. The focal length is adjusted monotonically, and the position of the light spots changes, moving to A', B', C', and D'. The distance between the light spots becomes shorter, indicating that the focusing direction is correct. Continue to transfer along the previous adjustment direction until the 4 light spots coincide, and the focus is achieved. On the contrary, if the 4 light spots at the first focal length are located at A', B', C', and D', and the 4 light spots at the second focal length are located at A, B, C, and D, it means that the focus adjustment direction is wrong and needs to be adjusted in the opposite direction until the 4 light spots coincide and the focus is achieved. It can be understood that the change in the distance between the light spots can also be described by more concentrated (equal to a decrease in the distance between the light spots) or more dispersed (equal to an increase in the distance between the light spots).

[0069] In some cases, the result of the trial monotonic adjustment of the focus is judged by manual observation, that is, the change in the spot distance on the target area is directly observed by the human eye, and then the focus adjustment is achieved manually or by control commands, and finally focusing is achieved. In other cases, the result of the trial monotonic adjustment of the focus is automatically determined by the system, that is, in the image captured by the imaging unit, the outline of the spot is automatically extracted, the distance between the center point of the spot and different spots, and the spot distance at different focal lengths are calculated, the adjustment direction is determined according to the change in the spot distance, and the focus adjustment is controlled until the spots coincide and focusing is achieved. The overlap of the spot positions refers to the overlap of the centroid of the spot or any specified feature point, for example, when the spot is circular, it can be the center of the circle; for example, when the spot is a right-angled isosceles triangle, it can be the vertex of the right angle.

[0070] Example 2

[0071] refer to Figure 1 This example is described on the basis of Example 1, and the difference between it and Example 1 is that the imaging system can also be provided with a laser rangefinder.

[0072] The laser rangefinder can obtain the rough distance between the variable-focus objective lens and the target area (the area to be operated on), and then roughly adjust the focal length of the variable-focus objective lens according to the rough measured distance, thereby ensuring that the depth of field range of the variable-focus objective lens covers the rough measured distance, making the focus laser spot in the target area clearly visible; the laser rangefinder can speed up the focusing speed and reduce the focusing time.

[0073] Embodiment 3:

[0074] refer to Figure 6 , this example is described based on any of the aforementioned embodiments, the difference being that the exterior mirror system is further provided with a fluorescent light path component.

[0075] The fluorescence optical path components include a beam splitter, a fluorescence filter, an imaging lens group, and a photoelectric converter. Fluorescence can be stimulated by irradiating a specific wavelength to the target area. The fluorescence reaches the photoelectric converter (such as a black and white camera, a color camera) through a variable focus objective and a fluorescence optical path to generate a fluorescence image. The fluorescence image can be superimposed with the image generated by visible light, thereby superimposing the information of the fluorescence image (such as vascular structure) with the information of the visible light image, which helps doctors obtain richer structural information.

[0076] The fluorescent light path components can also be two groups, so as to form a three-dimensional fluorescent image, see Figure 8The two fluorescence images are combined to form a three-dimensional fluorescence image, the two visible light images are combined to form a three-dimensional image of visible light, and the two are combined to form a three-dimensional image of superimposed fluorescence and visible light; alternatively, the fluorescence image can be first superimposed with the visible light image from the same optical path, and then combined with the superimposed image of another group of optical paths to generate a three-dimensional image.

[0077] Example 4

[0078] The present invention also provides an autofocus exterior mirror system, comprising: a trolley, a robotic arm, an imaging system, and input and output devices, wherein the imaging system includes an image acquisition device, a control unit, and a calibrator, and the specific structure is as described in Example 1.

[0079] The first end of the robotic arm can be connected to the trolley. It can be understood that the first end of the robotic arm can also be connected to a fixed structure, such as fixed to an operating table, the ground, a wall, a ceiling, etc. The second end of the robotic arm is connected to the image acquisition device. The robotic arm can have 6 joints, 7 joints or more joints, and can achieve at least 6 degrees of freedom of movement, and flexibly adjust the position and angle of the image acquisition device. In some examples, sensors are provided at the joints of the robotic arm to accurately control the position of the image acquisition device connected to the end. There can be multiple sensors, such as angle sensors, force sensors, position sensors, etc. A separate force sensor can also be installed at the end of the robotic arm to increase the control accuracy of the image acquisition device. Preferably, the force sensor is a six-dimensional force sensor.

[0080] See also Figure 5 , Figure 5 An exoscopic system for imaging a surgical site is schematically shown, comprising:

[0081] The trolley 100 is provided with a memory and a processor, and input and output devices including a display 400, and a foot switch, a keyboard, a mouse, a microphone, etc. not shown. The trolley can be moved to a desired position and fixed. The display is preferably a 3D display;

[0082] Robotic Arm 200,

[0083] The image acquisition device 300, it is understood that 300 may also include an illumination device and / or a range finder;

[0084] The first end of the robot arm 200 is connected to the trolley, and the second end is connected to the image acquisition device 300 through a switching tool;

[0085] The robotic arm 200 has multiple articulated arms and joints, and has multiple degrees of freedom, for example, 4, 5, 6, or 7 degrees of freedom, and preferably has at least 6 degrees of freedom; a force sensor (for example, a six-dimensional force sensor) can be set at the end of the robotic arm 200, and a force sensor can also be set at each joint.

[0086] The processor may control the robot arm 200 through a corresponding control unit according to one of the following modes:

[0087] - Automatic mode,

[0088] - Collaboration mode,

[0089] In the automatic mode, the processor automatically calculates the motion trajectory between the current position of the robot arm 200 and the position setting point, and moves the robot arm 200 from its current position and orientation to the position setting point and orientation setting point through the control circuit, so that the image acquisition device moves to the preset position.

[0090] In the collaborative mode, the control circuit assists the manipulator 200 to move in the direction of the force applied by the operator. The force applied by the operator can be applied to the image acquisition device or an axis of the manipulator 200, and these forces are measured and calculated by means of one or more sensors mounted on the end of the manipulator 200 and / or each axis thereof. Geometric constraints can be integrated in the collaborative mode to limit the movement of the manipulator 200, and thus help to improve the safety of medical procedures. For example, the movement can be constrained to be within a certain area, outside a certain area, along a certain axis or curve, around a certain point, etc. The constraints can be defined by any type of geometric shapes and related behaviors. In the collaborative mode, the control circuit helps the operator place the image acquisition device into a preset position setting and orientation setting. In short, by dragging the end of the joint support arm or the image acquisition device connected to the end of the joint support arm, the joint support arm can perform auxiliary movement according to the magnitude and direction of the force, so that the end of the joint support arm or the image acquisition device moves to the required position.

[0091] The image acquisition device includes a variable-focus objective lens and two imaging units, each of which includes an imaging lens group and a photoelectric converter (such as a black-and-white camera or a color camera). In some examples, the imaging unit may also include a variable-power lens group.

[0092] The calibrator includes one or more calibration components, each of which includes a calibration light source capable of emitting a focusing laser. The focusing laser is irradiated to a target area through 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 manually by a control unit or by a user to change the focal length of the variable-focus objective lens, thereby achieving focusing.

[0093] Embodiment 5:

[0094] refer to Figure 8 , this example is described on the basis of Example 4, the difference being that the first end of the robot arm 200 is fixedly connected to the ceiling of the operating room. The robot arm 200 has a larger range of motion and more movable joints, and the trolley is communicatively connected to the control unit of the robot arm, and can be retracted and placed near the ceiling when not in use. It can be understood that the first end of the robot arm 200 can also be connected to the wall of the operating room or the bed, which are all solutions of the present invention.

[0095] Example 6

[0096] The present invention provides a surgical microscope, comprising the imaging system of embodiment 1, a support and an eyepiece. When the microscope is moved to a suitable position by the support, the imaging system automatically focuses. Preferably, the support is a self-balancing arm.

[0097] Example 7

[0098] An automatic focusing method for an imaging system of the present invention adjusts the focus of a variable focus objective lens based on the position of a light spot generated by a focusing laser emitted by the calibrator in a target area until the position of the light spot in the image reaches a specified position, thereby achieving automatic focusing.

[0099] See also Figure 2 At the first focal length, the calibrator emits two focusing lasers to form two light spots A and B. The focus is adjusted monotonically to reach the second focal length. The position of the light spots changes and moves to A' and B'. The distance between the two light spots becomes shorter, indicating that the focusing direction is correct. Continue to adjust along the previous adjustment direction until the two light spots coincide, that is, focusing is achieved; conversely, if the two light spots at the first focal length are located at A' and B', and the two light spots at the second focal length are located at A and B, it means that the focus adjustment direction is wrong and needs to be adjusted in the opposite direction until the two light spots coincide to achieve focusing.

[0100] It is understood that the two focusing lasers can be arranged in a variety of ways, and can be arranged symmetrically or asymmetrically, see Figure 3 , set on one side of the vertical axis of the field of view / image, and two focusing lasers symmetrically distributed on the horizontal axis of the field of view / image, when the focal lengths are different, the light spot positions in the field of view / image are superimposed to form a track, as shown by the crossed dotted lines. When the two light spots overlap, focusing is achieved.

[0101] The number of focusing lasers can also be 3 or more, see Figure 4, at the first focal length, the calibrator emits 4 focusing lasers, forming 4 light spots A, B, C, and D. The focal length is adjusted monotonically, and the position of the light spots changes, moving to A', B', C', and D'. The distance between the light spots becomes shorter, indicating that the focusing direction is correct. Continue to transfer along the previous adjustment direction until the 4 light spots coincide, and the focus is achieved. On the contrary, if the 4 light spots at the first focal length are located at A', B', C', and D', and the 4 light spots at the second focal length are located at A, B, C, and D, it means that the focus adjustment direction is wrong and needs to be adjusted in the opposite direction until the 4 light spots coincide and the focus is achieved. It can be understood that the change in the distance between the light spots can also be described by more concentrated (equal to a decrease in the distance between the light spots) or more dispersed (equal to an increase in the distance between the light spots).

[0102] In some cases, the result of the trial monotonic adjustment of the focus is judged by manual observation, that is, the change in the spot distance on the target area is directly observed by the human eye, and then the focus adjustment is achieved manually or by control commands, and finally focusing is achieved. In other cases, the result of the trial monotonic adjustment of the focus is automatically determined by the system, that is, in the image captured by the imaging unit, the outline of the spot is automatically extracted, the distance between the center point of the spot and different spots, and the spot distance at different focal lengths are calculated, the adjustment direction is determined according to the change in the spot distance, and the focus adjustment is controlled until the spots coincide and focusing is achieved. The overlap of the spot positions refers to the overlap of the centroid of the spot or any specified feature point, for example, when the spot is circular, it can be the center of the circle; for example, when the spot is a right-angled isosceles triangle, it can be the vertex of the right angle.

[0103] Example 8

[0104] Another automatic focusing method for an exterior mirror of the present invention is described on the basis of Example 7, and also includes a pre-adjustment step. In the pre-adjustment step, a ranging laser is used to obtain a rough 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 rough measured distance, thereby ensuring that the depth of field range of the variable-focus objective lens covers the rough measured distance, so that the light spot of the focusing laser in the target area is clearly visible.

[0105] Example 9

[0106] Another automatic focusing method for the exterior mirror of the present invention is described on the basis of Example 7, and also includes fine adjustment. The fine adjustment is performed as follows: a focus window is selected in the image, and the area in the center of the image is selected as the focus window using the central area method, and then the image in the focus window is convolved using a Sobel operator, a Roberts operator, etc., so that each pixel point obtains a new gray value, and a square operation is performed to increase its gray difference. Finally, all gray values ​​in the window are averaged, and the obtained value is the final result of the evaluation function. The larger the value, the clearer the image. The focal length after focusing in the above-mentioned embodiment is used as a reference to determine the next fine focus range, and the clarity of all images obtained at different distances within the fine focus range is compared, and the focal length with the best clarity 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 10

[0108] Another autofocus method for an imaging system of the present invention includes the pre-adjustment step of Example 9, the autofocus step of Example 7, and the fine adjustment step of Example 9, thereby achieving fast and fine autofocus.

[0109] The features described in the embodiments of the present specification may be replaced or combined with each other. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments may be referenced to each other.

[0110] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An imaging system, characterized in that: include: Image acquisition device, control unit, calibrator; The image acquisition device comprises a variable focus objective lens and at least one imaging unit, wherein the imaging unit comprises an imaging lens group and a photoelectric converter; The calibration instrument can emit a focusing laser, and the focusing laser is irradiated to 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 to achieve focusing of the variable-focus objective lens.

2. The imaging system according to claim 1, characterized in that The direction of the light of the focusing laser before reaching the variable-focus objective lens is parallel to the optical axis of the variable-focus objective lens.

3. The imaging system according to claim 1, characterized in that The calibrator emits two or more focusing lasers, and determines the focus adjustment trend according to the change in the spacing of the light spots formed by the focusing lasers emitted by the calibrator in the target area when the variable-focus objective lens is at different focal lengths, and continues to focus until the positions of the light spots overlap to achieve focusing.

4. The imaging system according to claim 3, characterized in that The overlap of the positions of the light spots refers to the overlap of the centroids of the light spots or any specified feature points.

5. The imaging system according to claim 4, characterized in that: The position overlap of the light spots is determined by visually inspecting the target area.

6. The imaging system according to claim 4, characterized in that: The position overlap of the light spots refers to that the system automatically determines the position overlap of the light spots in the image to achieve automatic focusing.

7. The imaging system according to any one of claims 1 to 6, characterized in that: It also includes a rangefinder, which is used to measure and obtain a rough distance between the variable-focus objective lens and the target area, and the control unit pre-adjusts the variable-focus objective lens based on the rough distance.

8. The imaging system according to claim 1, characterized in that: The control unit also performs fine adjustment, which is performed as follows: a focus window is selected in the image, and then its clarity is evaluated through an evaluation function, a fine focus range is determined based on the focal length after autofocusing, and the clarity of images acquired at all different focal lengths within the fine focus range is compared, and the focal length with the best clarity is selected as the final focal length.

9. The imaging system according to claim 1, characterized in that: The image acquisition device includes at least two imaging units and can generate a 3D image.

10. The imaging system according to claim 1, characterized in that The image acquisition device comprises at least one fluorescence imaging unit.

11. The imaging system according to claim 1, characterized in that: Also included is a lighting device.

12. A surgical microscope system, characterized in that: An imaging system comprising any one of claims 1 to 12.

13. An exterior mirror system, characterized in that: An imaging system comprising any one of claims 1 to 12.

14. An automatic focusing method for an imaging system, characterized in that: The imaging system is provided with a calibrator, and the focus of the variable-focus objective lens is adjusted based on the spot position of the focus laser emitted by the calibrator in the target area to achieve automatic focusing. The focus laser is parallel to the optical axis of the variable-focus objective lens before reaching the variable-focus objective lens.

15. The automatic focusing method according to claim 14, characterized in that: The method further comprises a pre-adjustment step, in which a distance measuring laser is used to obtain a rough distance between the target area and the objective lens, and the focal length of the variable focus objective lens of the image acquisition device is adjusted based on the rough distance.

16. The automatic focusing method according to claim 14, characterized in that: It also includes fine adjustment, which is performed as follows: a focus window is selected in the image, and then its clarity is evaluated by an evaluation function, a fine focus range is determined based on the focal length after automatic focusing, and the clarity of images acquired at all different focal lengths within the fine focus range is compared, and the focal length with the best clarity is selected as the final focal length.

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