JPS5931435B2 - Stamp engraving method using laser beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for finely engraving a stamp using a laser beam using wood (generally boxwood), buffalo horn, ivory, or the like as a stamp material.

The present inventor has so far researched and developed the use of a laser beam to engrave a seal.

The target seals are those that are already made in large quantities by plastic molding, and the equipment itself is expensive and unprofitable, so special fine processing is required, which is generally called a registered seal or bank seal. be. The problem with such stamps is how to engrave them with high precision and efficiency. In order to solve these problems, the inventors of the present invention have conducted repeated experiments, and as a result, have noticed several errors.

First, the inventor initially considered a stamp engraving method as shown in FIG. Basically, a rotary disk 6 is fixed on a fixed bed 1, a large number of stamp materials 5 are held on the upper surface of the rotary disk 6, and an original drawing T is held on the lower surface of the rotary disk 6 in a vertically concentric manner. A laser oscillator 9 is arranged, a rotary disk 6 and a fixed bed 1
A processing information reading mechanism 10 is placed between the two. Then, the rotary disk 6 is rotated horizontally around the vertical axis while linearly feeding and driving in one direction left and right, and the machining information reading mechanism 10 reads the original drawing.
The processing information is read from the stamp material 5 based on this processing information.
The laser beam 20 irradiated onto the stamp face 5a was controlled intermittently. In this method, since the rotary disk 6 is fixed to the upper end of the vertical rotating shaft 21, the rotary disk 6 is likely to cause lateral vibration.

In particular, a rotary drive mechanism 2 is provided between the rotary disk 6 and the bed 1.
2 and the machining information reading mechanism 10, the rotary disk 6 becomes vertically longer, and the bearing structure is complicated and expensive in order to keep the vibration of the rotary disk 6 below a certain value.
In addition, it is mechanically difficult to adjust the light projection and reception angles of the light projector 16 and the light receiving image 1T of the processing information reading mechanism 10 after the original drawing 7 is attached to the lower surface of the rotary disk 6. It has been realized that it is difficult to achieve highly accurate and highly efficient seal engraving using the method shown in the figure. Next, the processing accuracy of the stamp is determined by the scanning line density of the processing points of the laser beam 20 on the stamp surface 5a of the stamp material 5.

In other words, as shown in Figure 6, the stamp surface of the stamp material after laser beam engraving is more or less uneven in the engraved part a and the non-engraved part b, but how to set the degree of this unevenness? The question becomes. Regarding this point, the present inventor previously proposed setting the parallel spacing of the scanning lines at the laser beam processing points to 0.03 mm to 0.07 mm (Japanese Patent Application No. 1983-62922). There, 0.05
It was revealed that mm is the upper limit when dealing with registered seals and bank seals. Furthermore, if the thickness was less than 0.03 mm, processing efficiency would decrease, and it was thought that this was a mechanical limit. However, this was also a mistake because it was based on the assumption that a device with the structure shown in Figure 7 would be used.
The upper limit of the parallel spacing between scanning lines is 0.05 mm when processing registered seals and bank seals, but it has been realized that even if the lower limit is made even smaller, processing can still be carried out with sufficient mechanical efficiency and high efficiency. . Furthermore, although there are various types of laser oscillators, carbon dioxide lasers are actually the most suitable from economical and other points of view, and their output is 30
I noticed that it was W~120W.

This invention was completed based on the above knowledge, and according to this invention, seals such as registered seals and bank seals can be engraved with a laser beam with extremely high precision and efficiency.

Hereinafter, the details of the apparatus for carrying out the method of this invention will be sequentially explained.

1 and 2, a pair of front and rear columns 2, 2 are erected on a fixed bed 1, and a workbench 3 is supported on these columns 2, 2 so as to be movable up and down.

A horizontal shaft 4 is installed on the workbench 3, and at one end of the horizontal shaft 4 (the left end in the figure) is a rotary disk 6 on which a large number of stamp materials 5 are held.
At the same time, a rotary disk 8 on which the original drawing 7 is held is fixed at the other end of the horizontal shaft 4 (the right end in the figure). And bed 1
On the top surface, a carbon dioxide laser 9 is arranged facing one rotary disk 6, and a photoelectric conversion type machining information reading mechanism 10 is arranged opposite the other rotary disk 8, respectively, in a fixed position. do. Both rotary disks 6 and 8 are driven to continuously rotate around the horizontal axis by a motor 12 installed on the workbench 3.
Continuous linear minute feed drive in the upward and downward directions perpendicular to the horizontal axis. As a means of driving the feed in the vertical direction,
The rotational power of the horizontal shaft 4 is transmitted to the nut 14 via the vertical drive mechanism 13, and the nut 14 connects to the lead screw 15 formed on the support column 2.
The entire workbench is designed to move downward relative to the bed 1 by rotating around it. One circular rotary disk 6
A large number of stamp materials 5 are held concentrically with respect to the horizontal axis 4 at regular intervals on the vertical outer end surface 6a of the stamp material.

Further, it is assumed that the original drawing 7 is held on the vertical outer end surface 8a of the other rotary disk 8. This original drawing 7 is written in black letters on a ring-shaped white paper, for example, and both rotary discs 6 and 8
The stamp material 5 and the original drawing 7 are held so that their rotational phase positions match. The processing information reading mechanism 10, as shown in FIG.
It consists of a light projector 16 that projects a detection light beam toward the original image 7, and a light receiver 17 using Cds that receives the reflected light beam.

An electric control circuit 19 connects the light receiver 17 and the carbon dioxide laser 9.
This electric control circuit 19 connects the light receiver 1.
Amplify the output of 7 according to the degree of black and white of one point on the original drawing,
The oscillation of the laser beam 20 from the carbon dioxide laser 9 was made intermittent. In such a case, both rotary disks 6 and 8 are integrated via the horizontal shaft 4, and are continuously rotated around the horizontal axis while being minutely fed in one direction up and down.

With this, the light point P of the detection beam projected from the projector 16 onto the original drawing 7 and the processing point P'' of the laser beam 20 irradiated from the carbon dioxide laser 9 onto the stamp surface 5a of the stamp material 5 are synchronized and placed on the original drawing. Incidentally, the reflected light beam of the detection light beam projected from the light emitter 16 onto the original drawing 7 is received by the light receiver 17, but the reflected light beam is strong on the white material surface portion of the original drawing 7. , is weak in the black part of the original drawing.Therefore, the strength of this reflected light beam is detected by the light receiver 17, and based on this detection signal, the laser beam 20 from the carbon dioxide laser 9 is oscillated via the electric control circuit 19. are interrupted and engraved as reverse characters on each stamp surface 5a.Now, in order to simultaneously engrave a large number of stamp materials 5 with a laser beam as described above, in the present invention, first, the focal point of the lens that converges the laser beam 20 is The stamp face 6
The spot diameter at the laser beam processing point V is set to about 100μ in accordance with the point a.

Then, the parallel interval between the scanning lines 1 of the laser beam processing point V as shown in FIG. , and the carbon dioxide laser 9 used is 30W~1
The output was set to 20W. Here, the upper limit of the parallel spacing between scanning lines 1 is set to 0.05 mm, because if this value is exceeded, the engraved part a and the non-engraved part b will be separated from each other in registered seals and bank seals, which are the object of the present invention. This is because a concave-convex diaphragm pattern that could be recognized with the naked eye was created at the boundary, and it had no value as a product.
In addition, the reason why the parallel interval of the scanning line 1 is set to 0.015 mm is because the mechanism for moving both rotary disks 6 and 8 in one direction up and down has a mechanical limit, and the existing laser This is because it is close to its limit in terms of responsiveness. Furthermore, if the laser output exceeds 100 W, the spot diameter becomes too large, making it impossible to perform elaborate engraving. Therefore, even if the laser output is permissible, the upper limit is 120 W, and the lower limit is 30 W from the viewpoint of working efficiency and the hardness of the stamp material.

As explained above, according to the method of this invention, the horizontal axis 4
The bearing structure is reasonable, and the stamp material holding rotary disk 6 and the original drawing holding rotary disk 8 fixed to both ends of the rotary disk do not run out during rotation.

Furthermore, the angles of light emission and reception of the light emitter 16 and the light receiver 17 can be easily adjusted. In addition, the scanning line density and laser output of the laser beam processing point Pl on the stamp surface of the stamp material 5 are optimized for engraving registered stamps and bank stamps.
The major feature of this technology is that it has become possible to engrave these stamps with a laser beam with high precision and efficiency.

[Brief explanation of drawings]

FIG. 1 is an overall schematic plan view of an apparatus for carrying out the method of the present invention;
FIG. 2 is a left side view thereof, and FIG. 3 is a right side view thereof. FIG. 4 is a perspective view showing the processing information reading mechanism, FIG. 5 is an explanatory view showing the state of the scanning line of the laser beam processing point by the above device, and FIG. 6 is an explanatory view showing the finished state of the stamp. FIG. 7 is a schematic longitudinal sectional front view showing a conventional device.
1... bed, 2... pillar, 3...
...Workbench, 4...Horizontal axis, 5...
Stamp material, 5a... Stamp surface of stamp material, 6... Rotating disk, 7... Original drawing, 8... Rotating disk, 9
... Carbon dioxide laser, 10 ... Processing information reading mechanism, 16 ... Floodlight, 17 ...
...Receiver, 19...Electric control circuit, 20...
...Laser beam, P... Light spot, P/...
...Laser beam processing point, l...Scanning line.

Claims (1)

[Claims] 1. The stamp material 5 is attached to one vertical outer end surface 6a of the rotary disks 6 and 8 fixed to both ends of one horizontal shaft 4, and the stamp material 5 is attached to the other vertical outer end surface 8a.
The original image 7 is held so that the rotational phase positions match each other, and the horizontal axis 4 is continuously rotated around the horizontal axis, and the original image is projected onto the original image from the projector 16 while being linearly driven in one direction up and down. The light point P of the detection beam and the processing point P' of the laser beam 20 irradiated from the carbon dioxide laser 9 onto the stamp surface 5a of the stamp material 5 are synchronized and scanned spirally over the original drawing and stamp surface, respectively, and the original drawing 7 is scanned in a spiral manner. The laser beam 20 from the carbon dioxide laser 9 is oscillated by receiving the reflected light of the detection light from the carbon dioxide laser 9 with the light receiver 17 and amplifying the output from the light receiver 17 according to the degree of blackness and whiteness of one point on the original drawing. In this method, the stamp surface 5a of the stamp material 5 is engraved with a laser beam by intermittent control. 0.015mm~0.05
A stamp engraving method using a laser beam, characterized in that the setting is set to mm.