JPH0825336B2 - Laser marking method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of marking a surface of a glass body with a desired color by using a laser beam.

[Prior Art] Laser marking is mainly used for marking electronic parts packages, watch frames, etc. that are difficult to print normally due to shape, material, and environmental conditions, and those that cause problems with printing ink. . Since the letters and numbers can be changed automatically by computer control, it is suitable for marking the serial number, lot number, etc. of a wide variety of mass-produced products.

The conventional laser marking method is a method of instantaneously melting and vaporizing and removing a minute portion of the material surface by the energy of laser light, and is a marking method by engraving or engraving rather than printing.

When such a laser marking method is applied to glass, YAG laser light with a short wavelength (about 1.06 μm) cannot be used because it passes through a transparent material, so the wavelength is long (about 10.6 μm).
μm) CO2 laser light that can be absorbed by this type of transparent material is used.

When glass is irradiated with CO2 laser light, the irradiated area on the surface of the material is melted, vaporized, and scraped off, leaving a milky white mark. A desired pattern can be engraved or engraved by forming the traces of milky white into letters, symbols, figures, or the like.

[Problems to be Solved by the Invention] However, in the conventional laser marking method as described above, the color that can be marked on glass is limited to milky white, and other desired colors such as red, blue,
There is a problem that it cannot be colored with yellow or green.

Further, since CO2 laser light has a long wavelength, it is difficult to print a fine pattern.

The present invention has been made in view of such problems in the related art, and an object of the present invention is to provide a laser marking method capable of marking an arbitrary color on the surface of glass.

[Means for Solving the Problems] In order to achieve the above object, the laser marking method of the present invention is a laser marking method for marking a surface of glass by using a laser beam, in which a desired color is applied to a surface of a substrate. The paint surface of the glass is applied, and the surface of the glass to be marked is aligned with this paint surface, and the laser light is irradiated through the glass on the paint surface in a desired pattern such as letters, figures, and symbols. In this way, the paint on the coated surface irradiated with the laser light is melted and transferred to the surface of the glass.

[Operation] When a predetermined laser beam passes through (transmits) the glass and irradiates the coated surface, the coating material irradiated with the laser beam is instantaneously melted by the laser energy and peeled off from the substrate. This molten paint evaporates as it is if nothing is on the coated surface, but according to the present invention, since the glass is overlapped, it adheres to the surface of the glass without evaporating. After the laser irradiation, when the glass is separated from the substrate, the paint adhered (transferred) remains on the surface of the glass. It is possible to transfer (mark) a desired pattern by selecting the irradiation pattern of laser light.

Then, by selecting the color of the paint, it is possible to perform marking of any color. Further, since the laser beam used in the present invention is a laser beam having a short wavelength that allows glass to pass through, for example, a YAG laser beam, it is possible to print a fine pattern.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a laser marking apparatus according to this embodiment, FIG. 2 is a sectional view of an essential part for explaining the operation of this embodiment, and FIG. FIG. 7 is a cross-sectional view of a main part showing a state of transfer.

The substrate 10 may be a metal plate made of aluminum or stainless steel having a flat surface, or may be paper, an acrylic plate, or the like. The surface 10a of the substrate 10 is coated with a thick paint such as paint or ink of a desired color (for example, blue) to form a coated surface. On this painted surface 10a, the surface 12a of the transparent glass plate 12 to be marked is overlaid (matched).

A convex lens 14 and a mask 16 are arranged directly above the glass plate 12. The mask 16 is an opaque plate in which a desired pattern of characters, symbols, figures, etc. is preliminarily formed.

When the mask 16 is irradiated with parallel YAG laser light LA from a YAG laser generator (not shown) arranged above the mask 16, the YAG laser light LA passing through the mask pattern is condensed by the convex lens 14. Then, as shown in FIG. 2, an image is formed on the coated surface 10a of the substrate 10 through the glass plate 12 (transmission).

As a result, the coating material PA on the coating surface 10a irradiated with the laser light LA is instantly melted by the laser energy and the substrate 10
Although it is peeled off, it adheres (transfers) to the surface 12a of the glass plate 12 without evaporating because it is hermetically sealed.

Then, when the glass plate 12 is separated from the substrate 10, a transfer portion of the paint PA remains on the surface 12a of the glass plate 12 as shown in FIG. The pattern of this transfer portion corresponds to the mask pattern.

However, since the image formed by combining the laser light LA on the coating surface 10a is an inverted real image, the transfer (printing) pattern is similar to the inverted mask pattern.

As described above, in this embodiment, the mask 1 with the YAG laser light is used.
By projecting a pattern on the coating surface 10a with the convex lens 14 through 6, the paint PA on the coating surface 10a is melted in the shape of the pattern in plan view and transferred to the surface 1a of the glass plate 12 to form a glass surface. The pattern is marked on 12a. Therefore, the pattern can be colored with any color by freely selecting the color of the paint. Further, since the YAG laser beam having a short wavelength is used, it is possible to print a fine pattern using a fine mask pattern.

Note that the YAG laser light is applied to the coated surface 1 using a galvanometer mirror, etc.
It is also possible to use a scanning method in which desired characters, symbols, or figures are drawn by scanning on 0a.

[Effects of the Invention] The present invention has the following effects by having the steps (method components) as described above.

By irradiating a predetermined laser light, for example, a YAG laser light through the glass onto the coating surface matched to the glass, the coating material on the coating surface is melted by the laser energy so that it can be transferred to the surface of the glass. It is possible to mark in any color by freely selecting the color. In addition, since a laser beam having a short wavelength that passes through glass is used, it is possible to print a fine pattern.

[Brief description of drawings]

FIG. 1 is a perspective view showing a laser marking device according to an embodiment of the present invention, FIG. 2 is a sectional view of a main part for explaining the operation of the embodiment, and FIG. 3 is a glass in the embodiment. FIG. 4 is a cross-sectional view of a main part showing a state where the paint is transferred to the surface of the. In the drawing, 10 ... substrate, 10a ... painted surface, 12 ... glass plate, 12a ... glass plate surface, 14 ... convex lens, 16 ... mask, PA ... paint.

Claims (1)

[Claims] 1. A laser marking method for marking a surface of glass by using a laser beam, wherein the surface of a substrate is coated with a paint of a desired color to form a coated surface, and the glass to be marked on the coated surface. By irradiating a laser beam in a desired pattern such as letters, figures, symbols, etc. on the coated surface through the glass by melting the paint on the coated surface irradiated with the laser beam. A laser marking method, characterized in that it is transferred onto the surface of the.