Automatic Video Microscope Servo Control System
Continuous zoom optical system
A zoom system refers to an optical system in which the focal length is continuously changed within a certain range while the image position remains unchanged. At present, zoom lenses use changing the spacing between lens groups to change the focal length of the entire objective lens. When moving the lens to change the focal length, it is always accompanied by the movement of the image plane. Therefore, compensation for the movement of the image plane should be provided, mainly through optical compensation and mechanical compensation. At present, the latter is the mainstream method. The zoom lens needs to calculate the compensation curve based on the numerical relationship between the displacement of the zoom group and the compensation group, in order to design a cam mechanism that compensates for the movement of the image surface. The mirror tube with cam curve grooves was processed by rotation, achieving the goal of continuous doubling while ensuring the image position remains unchanged.
Multiplying automation transformation
The automation transformation of continuous zoom video microscope is to control the stepper motor to precisely rotate the zoom handwheel at different angles through a transmission device, achieving automatic adjustment of different magnifications. The design of the circuit control part mainly includes: hardware circuit design, microcontroller control program writing, and serial port data transmission part design. The hardware circuit mainly completes the shaping and frequency doubling of pulses, as well as the effective transmission of instructions sent by the microcontroller. The microcontroller control program mainly controls the specific rotation angle of the variable magnification handwheel. The serial data transmission part mainly completes the transmission of instructions and data from the upper computer, as well as effective feedback, to ensure the correct transmission of data.
Autofocus
Focusing refers to the process of changing the relative position of the object surface and the objective lens along the optical axis direction, so that the objective image relationship satisfies a Gaussian relationship, in order to obtain a clear initial image of the objective lens.
A PC based automatic focusing experimental platform has been established, with mature instruments such as JX4 automatic upright metallographic microscope and multimedia interactive experimental platform, and a series of focusing experiments have been conducted based on such experimental platforms. In the article, an embedded autofocus processing system was designed, and the PC based electromechanical autofocus search algorithm was embedded and ported, relying on an embedded processing system with small size, low power consumption, and convenient system integration to achieve.
