Microscopic DIC-oriented automatic focusing image acquisition device

Abstract

The utility model discloses an automatic focusing image acquisition device for microscopic DIC, and relates to the technical field of image acquisition. Comprising a gray-spot camera, a laser focusing module, a controller and a displacement table, wherein the gray-spot camera is electrically connected with the laser focusing module, the laser focusing module is connected with the controller through a serial port, and the controller is connected with the displacement table. In the DIC experiment process, the gray-spot camera is responsible for collecting DIC experiment photos, and the laser focusing module is responsible for monitoring whether the focus position is shifted or not. When the shape of an experimental sample is changed, the working distance between the surface of the sample and the lens is also changed, the laser focusing module detects that the focus position is changed through feedback of a laser signal at the moment, the offset is sent to the controller through a serial port, a stepping motor on a Z-axis guide rail is driven, and the laser focusing module is driven to focus. The whole camera moves up and down to find a focal plane, and real-time focusing is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of image acquisition, in particular to an automatic focusing image acquisition device for microscopic DIC. Background Art

[0002] At present, the most widely used non-contact optical measurement method in the field of measuring material deformation is DIC technology, namely digital image correlation method. The basic principle of the DIC method is to match nodes through image grayscale information, and the image grayscale information depends on the speckle pattern of the measured surface. The speckle randomly distributed on the surface serves as a carrier of deformation information and deforms together with the specimen surface. The speckle can be naturally generated or artificially produced. When conducting microscopic DIC experiments on small-scale samples, since the focal plane of the sample surface and the working distance of the lens are fixed, the deformation of the material will cause the focal length between them to change, causing the camera to lose focus and the collected image to become blurred, which ultimately affects the measurement accuracy. With the widespread application of optical technology and the continuous improvement of computer computing power, digital image correlation technology has set off a worldwide research boom, leading to the development of digital image correlation technology in many aspects. In terms of experimental hardware, optical imaging systems such as high-speed cameras, optical stereo microscopes, infrared cameras, and x-ray cameras have been introduced. However, most of the above imaging systems rely on manual focusing, which has the following disadvantages: it takes more time to focus; it is not suitable for samples that deform quickly; there will be subjective judgment, and the naked eye cannot accurately judge where the focus position is. Therefore, for those skilled in the art, how to perform automatic focusing to ensure the acquisition of high-quality images is an urgent problem to be solved. Utility Model Content

[0003] The utility model aims to provide an automatic focusing image acquisition device for microscopic DIC to solve the problems raised in the background technology, so that the device can make the camera focus in real time during the DIC experiment, ensure the image clarity and improve the experimental accuracy.

[0004] To achieve the above-mentioned purpose, the utility model provides the following solution: an autofocus image acquisition device for microscopic DIC, comprising a camera module and a translation stage, wherein the camera module comprises a gray point camera, a laser focus module, and a controller; wherein:

[0005] The gray point camera is electrically connected to the laser focus module, the laser focus module is connected to the controller via a serial port, and the controller is connected to the translation stage;

[0006] The gray point camera is used to take DIC experimental images;

[0007] The laser focusing module is used to monitor the focus position of the DIC experimental image and transmit the offset data to the controller;

[0008] The controller is used to receive the offset data and drive the translation stage to move to find the focal plane.

[0009] Preferably, the translation stage includes an XY translation stage and a Z-axis driving mechanism.

[0010] Preferably, the XY translation stage includes a first stepper motor, an X-axis motion guide rail, an X-axis tilt knob, a second stepper motor, a Y-axis motion guide rail, a Y-axis tilt knob, and a Z-axis tilt knob; the first stepper motor is electrically connected to the X-axis motion guide rail, the second stepper motor is electrically connected to the Y-axis motion guide rail, and the first stepper motor and the second stepper motor are also respectively connected to a controller for receiving control signals from the controller to drive the guide rail to move.

[0011] Preferably, the Z-axis driving mechanism includes a third stepper motor and a Z-axis motion guide rail; the third stepper motor is electrically connected to the Z-axis motion guide rail and is also connected to the controller; the Z-axis motion guide rail is connected to the camera module through an I-shaped bracket.

[0012] Preferably, the laser focusing module is a laser autofocus sensor.

[0013] Preferably, the laser autofocus sensor detects whether the image focus position changes according to feedback of the laser signal, and transmits the offset to the controller through the serial port.

[0014] Preferably, it also includes a point light source, and the point light source transmits the light source to the gray point camera through a lens barrel.

[0015] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects: when conducting a DIC experiment, the distance between the sample surface and the lens changes during the experiment, resulting in a blurred and out-of-focus camera image. The utility model uses a laser autofocus sensor to collect image clarity-related data, and adjusts the focus position in real time according to the sensor data to achieve autofocus, thereby ensuring that the camera image is in a clear process during the entire DIC experiment. Compared with manual focus, autofocus reduces the workload of operators, reduces the error rate of operation, improves image acquisition efficiency and accuracy, and enhances the degree of automation of image acquisition, and is suitable for different DIC application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a structural diagram of a camera module of the present utility model;

[0018] Figure 2 This is a structural diagram of the Z-axis drive mechanism of the utility model;

[0019] Figure 3 This is a structural diagram of the XY translation stage of the utility model;

[0020] Figure 4 This is an overall structural diagram of the device of the utility model.

[0021] Explanation of the accompanying drawings: 1. Gray point camera; 2. Laser focus module; 3. Objective lens turntable; 4. Lens barrel; 5. Point light source; 6. First stepper motor; 7. Second stepper motor; 8. X-axis motion guide rail; 9. Y-axis motion guide rail; 10. X-axis tilt knob; 11. Y-axis tilt knob; 12. Z-axis tilt knob; 13. Third stepper motor; 14. Z-axis motion guide rail; 15. I-shaped bracket. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The utility model aims to provide an automatic focusing image acquisition device for microscopic DIC, such as Figure 4 As shown, it includes a camera module and a translation stage, wherein the structure of the camera module is as follows Figure 1 As shown, it includes a gray point camera 1, a laser focus module 2, a controller, and a translation stage; wherein,

[0024] The gray point camera 1 is electrically connected to the laser focus module 2, the laser focus module 2 is connected to the controller via a serial port, and the controller is connected to the translation stage;

[0025] Gray point camera 1, used to capture DIC experimental images;

[0026] Laser focus module 2, used to monitor the focus position of the DIC experimental image and transmit the offset data to the controller;

[0027] The controller is used to receive the offset data and drive the translation stage to move to find the focal plane.

[0028] Furthermore, the translation stage includes an XY translation stage and a Z-axis driving mechanism.

[0029] like Figure 3 As shown, the XY translation stage includes a first stepper motor 6, an X-axis motion guide rail 8, an X-axis tilt knob 10, a second stepper motor 7, a Y-axis motion guide rail 9, a Y-axis tilt knob 11, and a Z-axis tilt knob 12; the first stepper motor 6 is electrically connected to the X-axis motion guide rail 8, the second stepper motor 7 is electrically connected to the Y-axis motion guide rail 9, and the first stepper motor 6 and the second stepper motor 7 are also respectively connected to the controller for receiving control signals from the controller to drive the guide rails to move.

[0030] like Figure 2 As shown, the Z-axis driving mechanism includes a third stepper motor 13 and a Z-axis motion guide rail 14 ; the third stepper motor 13 is electrically connected to the Z-axis motion guide rail 14 , and the Z-axis motion guide rail 14 is connected to the camera module through an I-shaped bracket 15 .

[0031] In this embodiment, the laser focus module is a laser autofocus sensor, which detects whether the image focus position has changed based on the feedback of the laser signal, and transmits the offset to the controller through the serial port. The user first performs manual focus to determine the focal plane, then starts the laser focus module for calibration, and the laser is irradiated to the sample surface and reflected to the laser sensor; during the experiment, the lens working distance changes, and the reflected laser line width will also change compared to the line width at the time of calibration. The change in laser line width is converted into a change in displacement offset, and the offset is obtained and the offset data is transmitted to the controller.

[0032] Furthermore, it also includes a point light source 5 , which transmits the light source to the gray point camera 1 through the lens barrel 4 .

[0033] Furthermore, it also includes an objective lens turntable 3 for switching eyepieces and objective lenses of different magnifications. By rotating the turntable, the shaking caused by hand vibration when observing objects can be reduced to ensure the stability of observation. The function of using the rotating turntable to switch lenses can be used to conduct experiments at different magnifications.

[0034] The working principle of the utility model is:

[0035] Before conducting a DIC experiment, you need to determine the focus position: it is used to focus by controlling the stepper motor to move the camera up and down, and at the same time control the XY translation stage to move the sample position to the center of the field of view. The image taken by the gray point camera is used to determine whether the camera as a whole has reached the focus position. When the camera reaches the focus position, the image is the clearest. At this time, turn on the laser focus module, perform laser marking, and use the current position as the focus position for subsequent laser focusing.

[0036] During the DIC experiment, the gray dot camera is responsible for collecting DIC experimental photos, while the laser focus module is responsible for monitoring whether the focus position is offset. When the current status of the experimental sample changes, the working distance between the sample surface and the lens will also change. At this time, the laser focus module detects the change in the focus position through the feedback of the laser signal, and sends the offset to the controller through the serial port, driving the stepper motor on the Z-axis guide rail to move the camera up and down as a whole to find the focal plane and achieve real-time focus. When the experimental process is in real-time focus, the experimental images collected by the gray dot camera are also relatively clear.

[0037] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core ideas of the utility model. At the same time, for those skilled in the art, according to the ideas of the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.

Claims

1. An autofocus image acquisition device for microscopic DIC, characterized in that: It includes a camera module and a displacement stage, wherein the camera module includes a gray point camera, a laser focus module, and a controller; wherein, The gray point camera is electrically connected to the laser focus module, the laser focus module is connected to the controller via a serial port, and the controller is connected to the translation stage; The gray point camera is used to take DIC experimental images; The laser focusing module is used to monitor the focus position of the DIC experimental image and transmit the offset data to the controller; The controller is used to receive the offset data and drive the translation stage to move to find the focal plane.

2. The autofocus image acquisition device for microscopic DIC according to claim 1, characterized in that: The translation stage includes an XY translation stage and a Z-axis driving mechanism.

3. The autofocus image acquisition device for microscopic DIC according to claim 2, characterized in that: The XY translation stage includes a first stepper motor, an X-axis motion guide rail, an X-axis tilt knob, a second stepper motor, a Y-axis motion guide rail, a Y-axis tilt knob, and a Z-axis tilt knob; the first stepper motor is electrically connected to the X-axis motion guide rail, the second stepper motor is electrically connected to the Y-axis motion guide rail, and the first stepper motor and the second stepper motor are also respectively connected to a controller for receiving a control signal from the controller to drive the guide rail to move.

4. The autofocus image acquisition device for microscopic DIC according to claim 2, characterized in that: The Z-axis driving mechanism includes a third stepper motor and a Z-axis motion guide rail; the third stepper motor is electrically connected to the Z-axis motion guide rail and is also connected to the controller; the Z-axis motion guide rail is connected to the camera module through an I-shaped bracket.

5. The autofocus image acquisition device for microscopic DIC according to claim 1, characterized in that: The laser focusing module is a laser auto-focus sensor.

6. The autofocus image acquisition device for microscopic DIC according to claim 5, characterized in that: The laser auto-focus sensor detects whether the image focus position changes according to the feedback of the laser signal, and transmits the offset to the controller through the serial port.

7. The autofocus image acquisition device for microscopic DIC according to claim 1, characterized in that: It also includes a point light source, which transmits the light source to the gray point camera through a lens barrel.

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