JPH01166893A - laser marking device - Google Patents

Abstract

PURPOSE:To efficiently carry out printing on plural objects by spitting a laser beam into plural beams by a prism and further, splitting the respective split laser beams into the laser beams in the parallel direction to an optical axis by plural mirrors in opposition to a part of these laser beams. CONSTITUTION:The objects 5 are conveyed in a lined-up state in order by eight in a line at equal intervals in the width direction on a conveyor line 8. When these objects 5 in a line are detected by a synchronous sensor 13, the laser beam LB is emitted from a laser beam oscillator 1 and passed through 90 deg.C mirrors 10A and 10B and directed in the longitudinal direction of the conveyor line 8 and split into two equally in the traverse direction by the beam splitting prism 11. The laser beams LB split into two respectively are then split into four equally in the longitudinal direction by mirrors 2A-2D and the eight laser beam LB in total are passed through cylindrical lenses 12, masks 3 and condenser lenses 4 respectively and attain the eight objects 5 on the conveyor line 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser marking device that prints on various objects using a laser beam.

[Prior art and its problems]

Laser light emitted from a laser oscillator is a light wave that has a single wavelength, the same phase, sharp directivity, does not diffuse, and therefore emits strong energy, so laser technology has been applied to various fields so far. . Laser marking is one of the applications of such laser technology. This marking method is non-contact and can accurately and repeatedly print high-quality markings on objects made of a wide variety of materials.

FIG. 5 shows the basic configuration of the laser marking device described above. This laser marking device includes a laser oscillator 1 that oscillates and emits a laser beam 1B, and a laser beam emitted from the laser oscillator 1. A mirror 2 that reflects LB in the direction of the object 5; a mask 3 that partially cuts the laser beam LB reflected by the mirror 2 to form a laser beam LB having a predetermined shape; and a laser beam that has passed through the mask 3. It is composed of a condenser lens 4 that images the LB onto an object 5. According to such a configuration, the laser beam LB is emitted from the laser oscillator 1 in a short time of one millionth of a second by the laser oscillation in the laser oscillator 1,
After this laser beam LB is reflected by a mirror 2, a part of it is cut off when passing through a mask 3 to form a laser beam LB to be printed in a predetermined shape, which is focused by a condensing lens 4 to be printed on a target. Object 5 is reached. Then, the laser beam LB evaporates a very shallow layer on the surface of the object 5 to perform printing. For example, printing is performed by removing ink from vapor labels and cartons, and by removing paint from metal cans to expose a high-contrast base.

In the laser marking described above, the emission time of the laser beam LB is very short, so no matter how fast the speed of the line conveying the object is, it is possible to print without stopping the line. Since it is a contact type, there is no risk of ink scattering or staining, and the coating on the object evaporates well and precisely. Furthermore, the characters and logos to be printed can be easily changed by simply replacing the mask 3, and it is also possible to automatically replace the mask 3.

By the way, in order to perform laser marking efficiently, it is necessary to use laser light 1B emitted from one laser oscillator 1.
Therefore, it is necessary to configure the printer to print on a plurality of objects 5.

Figures 6 and 7 each show one laser oscillator 1.
6 shows a laser marking device that prints on a plurality of objects 5 by using a galvanometer mirror 6 that changes the reflection direction of the laser beam LB emitted from the laser oscillator 1. The galvano mirror 6 is rotatably arranged so as to face the laser oscillator 1 via the galvano mirror 6.
Four mirrors 2 that reflect the laser beam LB from the mirror 2 are arranged, and a condenser lens 4 that focuses the laser beam LB reflected by each mirror 2 onto the object 5 is arranged so as to face each mirror 2. It is configured as follows.

According to the one shown in FIG. 6, the position where the laser beam 1B from the laser oscillator 1 which has passed through the mask 3 by rotating the galvanometer mirror 6 is reflected by each mirror 2 and reaches the condenser lens 4 is determined. By emitting the laser beam LB from the laser oscillator 1, printing can be sequentially performed on the four objects 5.

However, in the conventional device shown in FIG. 6, the galvanomirror 6 is rotated so that the laser beam LB reflected at the galvanomirror 6 reaches each mirror 2, so that the laser beam LB is transmitted from the laser oscillator 1. It is not possible to print on the four objects 5 unless the laser beam LB is emitted four times, which is not very efficient.

On the other hand, the conventional laser marking device shown in FIG. The laser beam LB that has passed through the half mirror 7 is reflected by the mirror 2, and the attached laser beam [B is directed to the object 5 through the mask 3 and the condensing lens 4, respectively. I'm trying to reach it.

According to the device shown in FIG. 7, approximately half of the light intensity of the laser beam LB emitted from the laser oscillator 1 is reflected by the half mirror 7, and the laser beam LB is reflected by the mask 3 and the condenser lens 4.
The target object 5 is reached through the half mirror.
At 7, about half of the remaining laser beam LB passes through the half mirror 7, is reflected by the mirror 2, and reaches the object 5 via the mask 3 and the condenser lens 4.

Therefore, printing can be performed on two objects 5 at the same time by emitting the laser beam LB once from the laser oscillator 1.

However, in the conventional device shown in FIG. 7, the attenuation rate of the laser beam LB in the half mirror 7 is about 2.
%, in order to print clearly on each object 5, it is necessary to use a laser oscillator 1 with a large capacity, and also to reduce the amount of light over the entire area of the laser beam LB. Since a plurality of laser beams are generated, the limit is that one laser oscillator 1 can print on two objects 5 at the same time.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser marking device that can overcome the problems of the conventional devices described above and efficiently print marks on multiple objects using a single laser beam emitted from a laser oscillator. do.

[Summary of the invention]

The present invention includes a laser oscillator, a beam splitting prism that splits the laser beam emitted from the laser oscillator, and a plurality of laser beams that split the plurality of laser beams split by the beam splitting prism into a plurality of laser beams, respectively. It consists of a mirror, and a plurality of condensing lenses that condense the laser beams split by the respective mirrors. According to the present invention having such a configuration, the laser beam emitted from the laser oscillator is split by the beam splitting prism into a plurality of laser beams in a direction parallel to the optical axis, and then each of the divided laser beams and this A portion of the laser beam can be further divided into laser beams in a direction parallel to the optical axis by multiple mirrors facing each other before reaching the target object, so it is possible to efficiently print on multiple targets at once. can be done.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same components as those of the conventional device described above will be described with the same reference numerals in the drawings.

1 and 2 show an embodiment of the laser marking device according to the present invention, and a known laser oscillator 1 is installed on the side of a conveyance line 8 that conveys a large number of objects 5 in an aligned state. The laser oscillator 1 is, for example, a CO2 laser. This laser oscillator 1 is provided with a laser beam emitting tube 9 that is positioned upright and protrudes from the upper end of the laser beam emitting tube 9. A 90' mirror 10A is attached to reflect the light in a direction transverse to the 8. Further, directly above the conveyance line 8, a laser beam 1B reflected by the 90' mirror 10A is provided.
A 90° mirror 10B is provided to reflect the light in a direction opposite to the transport direction of the transport line 8. Further, directly above the transport line 8, the laser beam LB reflected by the 90'' mirror 10B is directed in the optical axis direction, that is, onto the transport line 8.
A beam splitting prism 11 is disposed to divide the beam into two in the width direction. Said 906 mirror 10B
The beam splitting prism 11 is located directly above the center position of the transport line 8 in the width direction.

On the conveyance line 8 on both sides of the beam splitting prism 11, for example, four mirrors 2A, 28 are arranged at equal intervals in the width direction of the conveyance line 8.
．． 2C and 2D are arranged. These mirrors 2A~
2D is a laser beam LB split into two by the beam splitting prism 11, as shown in detail in FIG.
The beam splitting prism 11 is configured such that its lower end is gradually positioned lower as it moves away from the beam splitting prism 11 so that the beam can be divided into four equal widths in the vertical direction. After reflecting the remaining laser beam LB, the mirror 2B reflects the upper 1/3 range of the remaining laser beam, and then the mirror 2C reflects the remaining laser beam LB.
The upper half of the laser beam LB is reflected, and finally the mirror 2D reflects all of the remaining laser beam LB.

Moreover, these mirrors 2A to 2D are arranged so as to form an angle of depression of 45 degrees with respect to the horizontal line. As described above, the laser light LB, which has passed through the beam splitting prism 11 and each of the mirrors 2A to 2D and is 1/8 the size of the laser bottle light LB emitted from the laser oscillator 1, is transported by the mirrors 2A to 2D. It is positioned perpendicularly to the surface of line 8, and each laser beam L
A cylindrical lens 12 for collecting the laser beam at the position where B passes to obtain the energy necessary for printing is arranged as necessary, such as when the energy from the laser oscillator is small. In addition, a mask 3 for forming the laser beam LB into a predetermined shape to be printed is provided on the conveyance line 8 side by the cylindrical lens 12 disposed as necessary, and a laser beam 1B passing through this mask 3 is transferred to the conveyance line 8 side. Condensing lenses 4 for condensing light onto the object 5 on the cylindrical lens 12 are respectively disposed on extensions of the cylindrical lenses 12.

Note that the 90° mirror has one beam splitting prism 11 and each mirror 2A to 2D.

Each cylindrical lens 12, each mask 3, and each condensing lens 4 has an object 5 inside a casing (not shown).
It is supported so that its position can be adjusted according to the interval etc.

A synchronous sensor 13 is disposed on the side of the transport line 8 to detect that the object 5 has been transported onto the transport line 8, and this synchronous sensor 13 receives a signal indicating that the object 5 has been detected. When output, laser beam L8 is emitted from laser oscillator 1.
is now output.

Next, the operation of this embodiment having the above-described configuration will be explained.

On the conveyance line 8, eight objects 5 are sequentially conveyed in a row with equal intervals in the width direction, and the objects 5 in the negative row are conveyed by a synchronization sensor 13.
When detected, a laser beam LB is emitted from the laser oscillator 1, and this laser beam LB is transmitted to the 90° mirrors 10A and 10B.
is directed in the longitudinal direction of the conveying line 8, and is evenly distributed in the lateral direction by the beam splitting prism 11.
It is divided. The laser beams LB each divided into two are divided into four equally in the vertical direction by mirrors 2A to 2D, and a total of eight laser beams LB pass through the cylindrical lens 12, the mask 3, and the condensing lens 4, respectively. When eight objects 5 are reached on the conveyance line 8 and the objects 5 are beer bottle labels 14, a smooth surface coating 16 made of a resin solution is applied to the paper 15 as shown in FIG. A label 14 in which an ink layer 18 is laminated by printing on an aluminum layer 17 deposited via a
The ink layer 18, aluminum layer 17, and surface smooth coating 16 are evaporated into the shape of the lot number formed by each mask 3 by the heat of the laser beam LB, and the paper 15 is partially exposed. Therefore, due to the contrast between the paper 15 and the ink layer 18, the loft number can be clearly observed visually.

Figure 4 shows the beam splitting prism 11 mentioned above.
and shows the state in which the laser beam 1B is specifically divided by the mirrors 2A to 2D, and the laser oscillator 1
25IIJm vertically x 20mr horizontally when radiated from
The laser beam LB, which was a rectangle with a length of n, is transformed into a rectangle of 25# vertically x 10# horizontally by the beam splitting prism 11.
It is divided into #III+ laser beam LB, and further this vertical 2
5#X 10m horizontal laser beam LB sequentially hits mirrors 2A to 2D
The laser beam is divided into four laser beams LB. Then, this divided laser beam LB passes through the condenser lens 4 and reaches the target object 5 with the length of each side reduced by 1/2, but in reality, it is cut to some extent both vertically and horizontally by the mask 3. As a result, the part shown in solid black in FIG. 4 reaches the object 5.

In this way, according to this embodiment, by emitting the laser beam LB once from the laser oscillator 1, it is possible to simultaneously print on eight objects 5 at a time, so that printing can be performed efficiently. In addition, instead of forming a plurality of laser beams 1B by using a half mirror 7 to reduce the light intensity over the entire area of the laser beam LB, the laser beam LB is divided into eight parts. Since eight partial laser beams LB are formed, there is no risk of running out of printing energy even if printing is performed on eight objects 5 at the same time.

Roughly speaking, by changing the shape of the shielding part in each mask 3, different characters, numbers, etc. can be printed at the same time.

〔Effect of the invention〕

As explained above, according to the present invention, an excellent effect is achieved in that clear printing can be efficiently performed on a plurality of objects by emitting laser light once from a laser oscillator.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the laser marking device according to the present invention, FIG. 2 is a schematic front view of FIG. 1, FIG. 3 is a cross-sectional view showing a label printed with laser light,
The figure is an explanatory diagram showing a specific example of the state of decomposition of the laser beam in the embodiment of Figs. 1 and 2, Fig. 5 is an explanatory diagram showing a basic laser marking device, and Figs. 6 and 7 are respectively FIG. 2 is an explanatory diagram showing a conventional laser marking device. 1... Laser oscillator, 2.2A, 2B, 2C, 2D.
...Mirror, 3...Mask, 4...Condensing lens, 5
...Object, 10.10B...90' mirror, 11
...Beam splitting prism, 13...Synchronization sensor, 14...Label, LB...Laser light. Applicant's agent Shunsuke Nakao Figure 5 Figure 6E Kou 711

Claims (1)

[Claims] A laser oscillator, a beam splitting prism that splits the laser beam emitted from the laser oscillator, a plurality of mirrors that split the plurality of laser beams split by the beam splitting prism into a plurality of laser beams, and each A laser marking device that consists of multiple condensing lenses that condense laser light split by mirrors.