Anyone who has used a laser marking machine or has been in contact with the laser marking machine knows that when using this device, it involves the correct adjustment of the focal plane. The equipment manufacturer will emphasize the importance of focal length during equipment installation training and sample adjustment. Engraving the laser on the surface with the correct focal length is a key factor for the device to perform its performance correctly.
Today, the OEM laser marking machine manufacturer summarized some conventional laser marking machine focal length debugging methods.
First of all, before understanding the correct debugging method, we are nowhere to popularize and understand the correct definition of focal length: Focal length, also known as focal length, is the degree of light-gathering or divergence in the optical system, which refers from the center of the lens to the focus of light distance.
In laser marking equipment, after the laser is shaped by the laser, it will illuminate the focusing field lens with a parallel beam. Most conventional laser marking equipment uses a convex lens. The convex lens passes optical refraction to focus the parallel light beam to a focal point To form the focal plane. The vertical distance from the focal point of the convex lens to the focal length surface is what we call the focal length. We usually use F = how much to express its focal length. Most laser devices are marked with a focus field lens. For example: F = 163; F = 254, and so on.
The focusing field lens is a very important optical accessory in laser marking equipment. The parallel light generated by the laser can only be brought together after the focusing lens collects light and organizes it to exert its powerful capabilities.
Common laser marking machine focusing methods on the market can be divided into front focusing and rear focusing. The laser generates laser light and enters it into the deflecting lens of the galvanometer, and cooperates with the control software to form a preset marking pattern path. Galvanometer lens refracts laser to focus
Lens, and focus the energy to the focal plane to complete the laser engraving. From this photo, we can see very vividly that the focused beam of the laser is like a tapered needle, so if the laser energy is sharper, only the Z-axis of the laser marking machine can be shaken up and down, the focal plane. But what we can't see from this picture is that when the focused concentric beam passes through the focus, due to the characteristics of the laser (good monochromaticity, good coherence, good directionality, high brightness), the beam will not end or disguise In this way, they will continue to be scattered after crossing.
Therefore, if the laser focal length surface is too high or too low, the correct focal length surface will be missed. Only on the correct focal plane, after the laser reaches the target, the laser spot is the smallest, the energy is the largest, and the sound and color are the brightest. After we have fully understood the theoretical knowledge about laser focal length, let us list several conventional methods for finding focal length:
First: continuous luminescence test method.
After marking the coating software as approximately 1 square centimeter or circle, after conventional filling, the laser energy is transferred to a larger set of parameters. Use the frequency, then check the continuous mark, and then place the metal laser projection on the product surface. Continue to move the cursor and shake the Z-axis until the energy laser of the metal business card with the largest focal length, the clearest sound, and the brightest color basically become the focal length, resulting in multiple tests to find the appropriate focal length.
This method is suitable for fiber laser marking machine with a wavelength of 1064nm, semiconductor laser marking machine, end pump laser marking machine, 355nm laser marking machine, uv 532nm green laser marking machine, etc. You can find a piece of white paper on the 3D CO2 Laser marking machine, and then draw a box in the marking software. Continuous light will shake the Z-axis, and the focal plane is the best when printing on paper.
3d Co2 Laser Marking Machine
The second method: measuring distance.
Fiber laser marking machine supplier can notify the current equipment focal length data, and then record it, and then record after each product switch. You can point the end of the ruler directly at the surface of the product. The scale value refers to the reference surface on the objective lens, which can swing up and down to zoom the data. This interview method is applicable to all laser marking machines, but the disadvantage is that if the position of the laser engraving product is concave or the steel ruler is not suitable, this method is not practical.
Third: Double red light method.
This method requires the device to have this hardware configuration at the factory. Install one or two oblique red rays next to the galvanometer or galvanometer, and use the principle of the right triangle to find the other right side of the plane by using a fixed right side and two overlapping hypotenuses. By simply rocking up and down until the two red indicators coincide, you can quickly find the focal length. In addition, if the adjustment is not good or the middle offset is performed, it is easy to mislead and form the wrong focal length surface.