JPH0776167A - Laser marking method - Google Patents

Abstract

PURPOSE:To put a marking in a transparent or translucent resin body by a simple process. CONSTITUTION:The inside of a transparent or translucent resin body 10 is convergently irradiated with a YAG laser beam LA from the side of a marking face 10a. The resin near the light converging position is decomposed, the resin body 10 is scanned by the YAG laser beam LA such that a decomposed part CR of the resin viewing from the side of the marking face 10a draws a desired pattern, and the pattern is marked in the inside of the resin body 10. The YAG laser beam LA has a wavelength of about 1.06mum and passes through the transparent or translucent resin body 10. However, as the laser energy converges near to the light converging (focus) position, the resin as a non-crystal body is decomposed so as to generate cracks which look like scattered small gold or silver foils. These cracks or decomposed parts are distributed along the optical axis of the YAG laser beam LA used for the convergent beam irradiation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for marking the inside of a transparent or translucent resin body.

[0002]

2. Description of the Related Art For ornaments and souvenirs made of transparent or translucent resin such as acrylic resin, markings such as letters, symbols and figures may be put in the resin in order to enhance the decorative effect.

Conventionally, as a method for making this kind of marking, a method in which a piece of paper on which desired characters, figures, etc. are marked is inserted into a transparent or translucent resin body and integrally molded (first method) Alternatively, a transparent or translucent resin body is partially molded and the desired pattern is printed or stamped on the surface of the partial resin body (intermediate), and then the rest of the resin body is overlaid on the pattern printed surface. A molding method (second method) is known.

[0004]

In any of the conventional marking methods described above, marking is performed in the step of molding a transparent or semitransparent resin body, and the marking of the resin body after completely molded is performed. No marking can be placed inside. Further, the first method has a drawback that the aesthetics of the transparent or translucent ornament is impaired because the paper piece is inserted into the resin body. On the other hand, the second method has the drawbacks that the number of manufacturing steps is large, the work is troublesome, a mold is required for each pattern, and the cost is high.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for marking the inside of a transparent or semitransparent resin body in a simple process.

[0006]

In order to achieve the above object, the laser marking method of the present invention comprises a transparent or semi-transparent resin body which is internally focused and irradiated with YAG laser light from the marking display surface side thereof. The resin near the converging irradiation position is altered, and the YAG laser light is scanned onto the resin body so that the altered portion of the resin draws a desired pattern when viewed from the marking display surface side, and the resin body is scanned. A method of forming the marking of the pattern on the inside of the.

[0007]

The YAG laser light has a wavelength of about 1.06 μm and is transmitted through the transparent or semi-transparent resin body. However, since the laser energy is concentrated near the converging irradiation position, the resin which is an amorphous body is Deterioration causes cracks that are interspersed with small gold or silver foils. These cracks or altered portions are distributed along the optical axis of the YAG laser light that is focused and irradiated. Therefore, when viewed from the side of the marking display surface of the transparent or translucent resin body (from the normal direction of the surface), a plurality of deteriorated portions lined up in substantially the same direction in the resin body are one point or dot. Looks as. Therefore,
When the YAG laser light is scanned in a desired pattern when viewed from the marking display surface, the marking of that pattern is formed in the resin body.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

A laser marking method according to an embodiment will be described with reference to FIGS.

In this embodiment, acrylic resin is particularly suitable as the material of the transparent or translucent resin body to be marked, but other resins such as vinyl resin, epoxy resin, styrene resin, etc. are also possible. Is. The transparent or semi-transparent resin body may have any shape, but it is preferable that at least the surface used as the marking visible surface (marking display surface) is a flat surface.

According to this embodiment, as shown in FIG. 1, the YAG laser beam LA is condensed and irradiated from the marking display surface 10a of the transparent or semitransparent resin body 10 to the resin near the condensed position. And the YAG laser beam LA is scanned on the resin body 10 so that the modified portion CR of the resin draws a desired pattern when viewed from the marking display surface 10a side, and the pattern is marked inside the resin body 10. To do.

The YAG laser beam LA has a wavelength of about 1.06 μm, passes through the acrylic resin, but is condensed (focus).
Since the laser energy is concentrated in the vicinity of the position, the resin, which is an amorphous substance, is deteriorated, and cracks are generated such that small gold foils or silver foils are scattered. However, these cracks or altered portions CR are caused by the condensed and irradiated YAG laser light LA.
Distributed along the optical axis of. Therefore, when the marking display surface 10a of the transparent or semi-transparent resin body 10 is viewed from the normal direction of the surface, the plurality of altered portions CR arranged in a line in the resin body 10 are regarded as one point or dot. appear. Therefore, when the YAG laser beam LA is scanned in a desired pattern, for example, “MIYACHI”,
As shown in (A), the marking of the pattern is formed inside the marking display surface 10a.

When the transparent or semi-transparent resin body 10 on which the marking is applied is viewed from an oblique direction with respect to the normal direction of the marking display surface 10a, the marking pattern in the resin body 10 appears to be blurred, as shown in FIG. As shown in (B),
When viewed from the lateral direction, the altered part CR over a certain range
Although it can be seen that the dots are scattered, it cannot be identified as a marking pattern at all. Such visual effects can be used to enhance decorative value.

As described above, according to the laser marking method of this embodiment, the completely molded transparent or semitransparent resin body 10 is internally subjected to YAG from the marking display surface 10a side.
By converging and irradiating the laser beam LA, the resin in the vicinity of the converging and irradiating position is physically degenerated, and a plurality of discrete resin degenerated portions CR that are scattered along the optical axis of the YAG laser beam LA are formed. Generate it. Marking display surface 10a
Seen from the side, the plurality of discrete resin-altered parts C
R overlaps and looks like a dot. Marking display surface 10a
By scanning the YAG laser beam LA in an arbitrary pattern as viewed from the side, a series of dots are arranged in that pattern, and a marking pattern is formed in the resin body 10.

Therefore, in this embodiment, the molding process of the transparent or translucent resin body 10 for inserting the marking is not troublesome. Further, since an opaque substance such as paper is not inserted into the transparent or translucent resin body 10, the appearance as a transparent or translucent body is not deteriorated. Further, since the marking pattern is determined by the scanning pattern of the YAG laser beam LA, the pattern can be managed as data, the pattern can be easily created and changed, and no special pattern mask is required.

The depth position of the marking pattern is
It corresponds to the depth of the focused irradiation position of the YAG laser light LA and can be recognized by the viewing angle. Therefore, the depth position of the marking pattern can be arbitrarily selected by changing the depth of the converging irradiation position of the YAG laser light LA. Further, the thickness of the marking line can be arbitrarily selected by changing the light intensity (laser output) of the YAG laser light LA.

Further, as shown in FIG. 3, an opaque plate (for example, a white plastic plate) is provided on the surface 10b of the transparent or semitransparent resin body 10 opposite to the marking display surface 10a.
By attaching or adhering, the contrast of the marking in the resin body 10 can be increased, and the marking can be made easier to see.

FIG. 4 shows the structure of the main part of the laser marking apparatus in this embodiment. In this marking device, the transparent or translucent resin body 10 is fixed at a predetermined position, and the marking display surface 10a is directed to the condenser lens 18 side, and Y
The focus position of the AG laser beam LA is set inside the transparent or semi-transparent resin body 10, and the focus position is scanned in the XY directions to draw a desired pattern of characters, symbols, figures and the like.

In this laser device, laser light LA directly coming from a YAG laser oscillator (not shown) or coming through an optical fiber first enters the X-axis rotating mirror 14 and is totally reflected there. After that, the light is incident on the Y-axis rotating mirror 16 and is totally reflected by this mirror 16, and then the condenser lens 1
The light is condensed inside the transparent or semitransparent resin body 10 by 8. The position of the laser beam spot in the transparent or semi-transparent resin body 10 is the X-axis rotating mirror 14 in the X direction.
In the Y direction and the angle of the Y-axis rotating mirror 16 in the Y direction.

The X-axis rotary mirror 14 is adapted to be rotationally oscillated in the directions of arrows A and A'by the X-axis galvanometer scanner 20. On the other hand, the Y-axis rotating mirror 16
By the Y-axis galvanometer scanner 22, arrow B,
It is designed to rotate and vibrate in the B'direction. A scanning control signal from a control unit (not shown) is applied to both scanners 20 and 22 via electric cables 24 and 26.

However, each time the laser light LA from the YAG laser oscillator enters at a predetermined timing, both scanners 20 and 22 are synchronized with the laser light LA and the X-axis rotary mirror 14 and
By swinging the Y-axis rotating mirror 16 at a predetermined angle, the YAG laser beam LA is focused and irradiated to a predetermined position inside and inside the marking display surface 10a of the transparent or semitransparent resin body 10. Then, as described above with reference to FIG.
The resin deteriorates near the converging irradiation position of the AG laser beam LA, and dots are formed when viewed from the marking display surface side.
When the YAG laser beam LA is scanned so that these dots draw a desired pattern, as shown in FIG. 2A, the drawing pattern (characters) is formed inside the marking display surface 10a of the transparent or translucent resin body 10. , Symbols, figures, etc.) are formed.

In the laser device of FIG. 4, the transparent or semitransparent resin body 10 is fixed and the YAG laser beam LA is scanned. On the contrary, the YAG laser beam LA is fixed and the transparent or semitransparent resin body 10 is fixed. It is also possible to perform the same scanning as above by moving 10 with an XY table or the like.

Further, the laser marking method of the present invention is
It is not limited to marking naming on ornaments such as figurines and souvenirs made of transparent or translucent resin bodies, but also applicable to marking product lot numbers on industrial products.

[0024]

As described above, according to the laser marking method of the present invention, YAG laser light is condensed and irradiated from the marking display surface side of the transparent or semitransparent resin body to the condensed irradiation position. Since the resin in the vicinity is altered and the marking is formed inside the resin body by scanning the YAG laser beam in a desired pattern, it is possible to mark inside the transparent or translucent resin body in a simple process. it can. Further, when viewed from an oblique direction or a side with respect to the marking display surface, there is also a visual effect that the marking pattern becomes invisible, so that the value as a decorative article can be increased.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a laser marking method according to an embodiment of the present invention.

FIG. 2 is a diagram showing the appearance of a transparent or semi-transparent resin body that is marked by the laser marking method of the embodiment.

FIG. 3 is a diagram showing a configuration example in which a non-transparent plate is attached or adhered to a transparent or semitransparent resin body in an example.

FIG. 4 is a perspective view showing a configuration of a main part of a laser marking device used in an example.

[Explanation of symbols]

 10 Transparent or translucent resin body 10a Marking display surface 14 X-axis rotary mirror 16 Y-axis rotary mirror 18 Condensing lens 20 X-axis galvanometer scanner 22 Y-axis galvanometer scanner CR CR

Claims (1)

[Claims] 1. A transparent or semi-transparent resin body is focused and irradiated with YAG laser light from the marking display surface side to change the quality of the resin in the vicinity of the focused irradiation position, and when viewed from the marking display surface side, A laser marking method, characterized in that the YAG laser beam is scanned onto the resin body so that the altered portion of the resin draws a desired pattern to form the marking of the pattern inside the resin body.