JPS63118277A - Marking method - Google Patents

Abstract

PURPOSE:To enable such a printing that bridge parts of images are inconspicuous, through a simple process, by spacing an opaque stencil and a body to be marked by such a distance that print patterns cut out in the stencil are projected in a blurred form on the body and the bridge parts are not printed, and printing the print patterns on the body by a laser beam. CONSTITUTION:A laser beam is condensed to a predetermined beam width so as to have an energy density necessary for marking, by a convex lens 1. By the laser beam, print patterns provided in an opaque stencil 2 are projected on a body 3 to be marked, whereby the patterns are printed on the body 3. The stencil 2 is spaced from the body 3 by a distance l, whereby the print patterns are projected on the body 3 in a blurred form. By minimizing the width of bridge parts of the print patterns and selecting an appropriate value of l, it is possible to obtain a satisfactorily usable print with the bridge parts left inconspicuous.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a marking method for printing various patterns on the surface of an object using a laser beam.

[Conventional technology] More than 20 years after its invention, lasers are now used for drilling holes.

It is attracting attention in various processing technology fields such as cutting and welding. Marking devices that print various patterns on the surface of objects using laser beams are also already known.

Some conventional marking devices that use a laser beam print a pattern by irradiating a laser beam onto an object to be marked through a stencil with a print pattern punched out.

FIG. 2 is a diagram showing a conventional marking method using a laser beam. In this figure, 21 is a convex lens that is an optical system that focuses the laser beam emitted from the laser light source into a predetermined beam width, 22 is an opaque stencil on which a printing pattern is formed, and 23 is an object to be marked such as glass or plastic. be.

In this conventional method, the opaque stencil 22 and the object to be marked 23 are placed in close contact with each other, and the laser beam is focused to a predetermined beam width by the convex lens 22.
The opaque stencil 22 is illuminated. This beam width is set to provide the energy density necessary to mark the object to be marked 23.

Therefore, the printing pattern formed on the opaque stencil 22 is projected and printed onto the object to be marked 23 by the laser beam.

[Problems to be solved by the invention] However, with this conventional marking method, for example, r
Considering the case of printing AJ, in order to print this character on the object to be marked 23 with a laser beam, an opaque stencil 22 is used so that a part of this character is transmitted and other parts are not transmitted. It turns out. There are two types of opaque stencils. One is a transparent material 3 such as Zn5e as shown in FIG. 3(a).
The other is a metal plate 32b or 32b2 with a printed pattern punched out as shown in FIG. 3(b).

However, both of these opaque stencils have advantages and disadvantages. That is, a carbon gas laser is usually used as a laser light source, and the wavelength of this laser is 10.6.
7zm, and there are few transparent materials that transmit light of this wavelength. Further, an anti-reflection film is required for the optical system for transmitted light, but since the energy of the laser is extremely high, this anti-reflection film becomes useless in a short period of time.

Therefore, the opaque stencil shown in FIG. 3(a) is very expensive.

Further, in the case of the opaque stencil shown in FIG. 3(b), there are many cases in which a desired pattern cannot be formed unless the bridge B□+82 is provided.

In this case, since the bridge portion is not printed, in order to prevent this, as in the example shown in FIG. It is necessary to perform overlapping printing using an opaque stencil consisting of the plate 32b2. Therefore, the marking process becomes complicated and difficult.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a marking method that allows printing in which the bridge portion is not conspicuous through a simple process.

[Means for Solving the Problems] In order to achieve this object, the present invention uses an opaque stencil and an opaque stencil to such an extent that the printed pattern is blurred and projected onto the object to be marked, so that the bridge portion is not printed. The object to be marked is placed apart from the object to be marked, and a printing pattern punched out of the opaque stencil is printed on the object to be marked using a laser beam.

[Operation] By doing this, the line width of the bridge portion is extremely narrow, so even if the printed pattern is projected slightly blurred, the bridge portion will not be noticeable. On the other hand, although the printed pattern is projected slightly blurred, blurring hardly poses a problem for the printed pattern.

[Example] The present invention will be described in detail below based on one drawing. FIG. 1 shows the scheme of an embodiment of the marking method according to the invention. In this figure, l is a convex lens as an optical system that focuses the laser beam emitted from the laser light source into a predetermined beam width, 2 is an opaque stencil with a printed pattern punched out, and 3 is the object to be marked, such as glass or plastic. It is.

The laser beam is narrowed down to a predetermined beam width by a convex lens l so as to have the energy density necessary for marking. By this laser beam, the printing pattern formed on the opaque stencil 2 is projected onto the object to be marked 3 and printed.

Here, by separating the opaque stencil 2 from the object to be marked 3 by a distance an, the printed pattern is projected onto the object to be marked 3 in a blurred manner.

For example, a pattern with a width of about 1 to 1.5 mm and a bridge part of about 0.1 to 0.2 mm are provided on an opaque stencil made of a metal plate with a thickness of 0.2 to 0.3 mm.
When 1=5 mm, the bridge portion is inconspicuous and clear printing can be created.

In this way, by making the bridging part as narrow as possible and selecting an appropriate value for the text, it is possible to make the bridging part inconspicuous and to print enough to be usable.

In the above embodiments, a lens is used for the optical system, but it goes without saying that it is also possible to use a mirror. Needless to say, this method can be applied not only to the one-shot method in which a fixed beam is irradiated, but also to the scanning method in which printing is performed by scanning a linear or band-shaped laser beam.

[Effects of the Invention] As is clear from the above description, according to the present invention, by arranging the opaque stencil and the object to be marked apart from each other, the printed pattern can be marked to the extent that the bridge portion is not printed. By projecting the image onto the processing object in a blurred manner, it becomes possible to print without making the bridge part stand out.

Therefore, it is possible to perform printing that is sufficiently usable without using expensive stencils or overprinting.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of an embodiment of the marking method according to the present invention, FIG. 2 is a diagram showing a conventional marking method using a laser beam, and FIGS. 3(a) and (b) are diagrams showing opaque It is a figure explaining the printing pattern of a stencil. In the figure, l: Convex lens 2: Opaque Stencil 3: Agent for marked object Patent attorney 1) Haru Kitatake Figure 1 Figure 21 ¥1 (Q) (b) Figure 3 Procedural amendment (1, t)

Claims (1)

[Claims] An optical system that narrows the laser beam emitted from the laser light source to a predetermined beam width, an opaque stencil with a printed pattern having bridges punched out, and the object to be marked are placed in this order, and the printed pattern is formed. The opaque stencil and the object to be marked are placed so far apart that a bridge is not printed due to blurred projection onto the object to be marked, and the printed pattern punched into the opaque stencil by a laser beam is printed on the object to be marked. A marking method characterized by printing on the processed object.