The galvanometer, simply put, is a type of scanning mirror used in the laser industry, professionally known as a high-speed scanning galvanometer. The so-called galvanometer, also known as an ammeter, follows the design method of the ammeter, with the lens replacing the pointer and the signal from the probe replaced by a direct current signal controlled by a computer to complete the predetermined action.
Like the rotating mirror scanning system, this typical control system uses a pair of fold mirrors. The difference is that the stepper motor that drives the mirrors is replaced by a servo motor. The use of position sensors and the design of negative feedback loops in this control system further ensure the accuracy of the system, and the scanning speed and repeated positioning accuracy of the entire system reach a new level.
The laser galvo scanning system includes five parts: laser emission device, galvanometer system, control system, PC end, and projection screen. The laser emission device mainly produces laser beams and emits them outward. The galvanometer system consists of galvanometer motors and dual galvanometer sets. The scanning motor is the executing mechanism of the system, and the galvo mirror with the reflection film is fixed on the motor shaft of the galvanometer.
The dual galvanometer set refers to the two reflection mirror pieces fixed on the galvanometer motor shaft, namely the X-axis and Y-axis. The mirror piece on the X-axis is responsible for scanning, while the mirror piece on the Y-axis is responsible for scanning. The control system includes two parts: control and drive. The control part is responsible for controlling the deflection angle of the galvanometer, and the drive circuit is a position-following control system, mainly responsible for receiving control commands from the PC end for the galvanometer motor and conducting corresponding command operations. The projection screen is the working plane area where the laser finally arrives.
The galvanometer scanning first directs the laser beam generated by the laser emission device to the X-axis mirror, after reflecting, it enters the Y-axis mirror, and after the second reflection of the Y-axis mirror, it can be projected onto the working plane to form a scanning point. Then, by driving the X and Y beam deflectors consisting of the galvanometer motors to deflect, the movement of the laser beam in the predetermined scanning range is realized, completing the scanning of the image. Each beam deflector has a special reflection mirror (different coating of the film can reflect different wavelengths of laser), and the different deflection methods of the two mirrors can make the laser scan different graphics, thereby printing different models.