How to choice the field lens when buy a laser marking machine

March 8, 2023
Latest company news about How to choice the field lens when buy a laser marking machine

When buying laser marking field mirrors, of course everyone wants to spend the least amount of money to do more things. Before we don’t understand the parameters of laser marking field lens, it may be counterproductive. Riselaser will talk to you about laser marking Misinterpretation of standard airport mirror parameters.

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Format: The actual marking format of the field lens is larger than the parameters given by the manufacturer. For example, the commonly used 160 focal length field lens, everyone thinks that the maximum marking format is 110*110, but the normal situation is that in the case of 10 spots, F160 can actually hit about 125*125, and 12 spots, the actual size can reach 120 *About 120, 15 spots, marking format is 110*110. For a 200*200 field lens, under the condition of 10 spots, the marking format can reach 230*230.

 

Focal length: The focal length of the field lens is not equal to the distance between the field lens and the marking object. The distance between the field lens and the marking object is called the working distance. The working distance of the field lens is greater than the focal length, and the longer the focal length, the greater the gap between the working distance of the field lens and the focal length. For example, a field lens with a focal length of 160mm may work at a distance of about 190mm, while a field lens with a 430mm focal length may work at a distance of more than 480. There is no strict calculation formula between the working distance and the focal length. The length is related to the manufacturing process of the field lens, so the working distance can only be roughly estimated. Once you have a rough estimate of your working distance, you should be able to quickly find the sweet spot for marking with photoresist.

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Note: The field lens should not be as large as possible. Some customers said that the 110*110 field mirror can only mark products within the format of 110*110, while the 300*300 field mirror can mark any product within 300*300. Then why don't I choose the 300*300 field lens? It can be applied to marking more products. This kind of thinking is very one-sided. We know that the larger the marking area of the field mirror, the premise is that the focal length of the field mirror is very long. Long focal length field lenses have several disadvantages: The laser reaches the surface of the object after such a long focal length. At this time, the energy loss of the laser is very large, so the marking depth will be very shallow. Therefore, to use a large format field lens, a higher power laser must be used. The second disadvantage is that the focal spot of the field lens with a long focal length will be thicker, which means that the lines will be thicker and the fineness will be worse. If the current product requires precise, clear and deep marks, rashly using a large format field lens may not meet the needs of customers.

 

For products with certain undulations on the surface of the object, choose a field lens with a longer focal length. We know that the longer the focal length of the objective lens and the greater the depth of focus, then there will be certain fluctuations on the surface of the object, and marking can also be achieved. This is why using a long focal length field lens can mark slight undulations on the surface of the object.