JPH0420787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser printing device, and more particularly to a laser printing device in which a mask for imparting a printing pattern to a laser beam can be placed at an optimal position.

The technology of printing various patterns on the surface of objects using the energy of laser beams is already known, and in conventional laser printing devices, the laser beam from the laser oscillator is masked, that is, the transmittance of the laser beam is The laser beam is irradiated onto a plate usually made of metal, on which a predetermined pattern of 0 parts and 1 parts has been formed, and the predetermined pattern is imparted to the laser beam using this mask. Then, a laser beam provided with a predetermined pattern is focused by a condensing lens and irradiated onto an object to be printed, thereby printing the pattern on the object to be printed.

However, in conventional laser printing devices, the mask is placed and fixed in the path of the laser beam, so in order to change the pattern, it is necessary to change the mask to a mask with the desired pattern each time. It was impossible. As a result, it takes time and effort to replace masks and manage various types of masks, and it is difficult to print a lot number as a printing pattern for each or a certain number of printing objects that are conveyed continuously or intermittently. was virtually impossible.

Therefore, the printing pattern can be easily changed by arranging multiple masks in a superimposed manner, and rotating and moving the mask with the pattern to be printed as appropriate so that it is positioned within the passage path of the laser beam. A laser printing device capable of printing has been proposed. However, it is not preferable for the position of the print pattern between the laser oscillator and the condensing lens to fluctuate each time the mask is replaced, from the viewpoint of maintaining print quality, since a practical laser beam is not a perfectly parallel beam.

In view of the above points, it is an object of the present invention to provide a laser printing device that can perform high-quality printing. A plurality of masks on which patterns are formed are arranged in a superimposed manner in the traveling direction of the laser beam, and one of the patterns is selectively exposed to the path of the laser beam to print on the laser beam. In a laser printing device that applies a pattern and prints on the surface of an object, a moving mechanism is provided on the lower surface of the case that supports the mask group to move the mask group forward and backward along the traveling direction of the laser beam, and this moving mechanism The mask on which the pattern to be printed is formed and located in the laser beam path is configured to be adjustable and movable to a predetermined position.

The present invention will be explained below with reference to illustrated embodiments. FIG. 1 is a diagram showing the entire laser printing apparatus. A laser beam 3 emitted from a laser oscillator 1 into a conduit 2 is transmitted through a mask portion 5 disposed within a slit 4 of the conduit 2. FIG. As is well known, the laser beam 3 is a substantially parallel beam, and the mask portion 5 is provided with a predetermined pattern consisting of a portion where the transmittance of the laser beam is zero and a portion where the transmittance is 1. The laser beam 3' transmitted through the mask portion 5 is given a pattern according to the portion where the transmittance is 1.
The laser beam 3', which has been patterned by the mask section 5, is then condensed by a condensing lens 6 and irradiated onto a label 8 attached to the circumferential surface of the container 7, thereby printing the pattern.

The mask section 5 will be explained in detail with reference to FIGS. 2 and 3. The mask section 5 includes a plurality of rotatable masks 11 to 16 attached to a rotating shaft 10 supported by a case 9. Each of the masks 11 to 16 constituting these mask groups includes
A large number of circular holes 17 are provided at equal intervals on concentric circles. For example, in this embodiment, 10 circular holes are provided on the innermost circumference, 20 circular holes each on the second and third circumferences, and 40 circular holes on the outermost circumference. Moreover, the circular holes 17 of each of the masks 11 to 16 are formed so as to be located on the circumference of the same radius from the rotating shaft 10 for each circumference, and therefore all of the circular holes 17 of the six masks 11 to 16 are It is now possible to superimpose the . These circular holes 17 are arranged so that at least one place remains as a space 17a on each circumference of each mask 11 to 16, and other than that,
A pattern disk 19 on which characters such as alphabet letters or codes are punched out is attached.

A gear 20 is carved on the outer periphery of each of the masks 11 to 16, and the six masks 11 to 16 are connected to the gear 20 by six drive motors 21 arranged correspondingly. It is designed so that it can be rotated individually and independently via each of the small gears 22 that mesh with each other. A through hole 23 is provided on both sides of the case 9 that accommodates the mask group according to the above configuration so as to match the height position at which the laser beam 3 travels. The case 9 has an axial movement mechanism 24 that reciprocates in the axial direction of the rotating shaft 10, that is, the traveling direction of the laser beam 3, and an axial moving mechanism 24 that reciprocates in the direction perpendicular to the rotating shaft 10 (left-right direction in FIG. 2). It is fixed on a position adjustment device 26 equipped with a moving mechanism 25 for moving. Both moving mechanisms 24 and 25 can be driven by various means such as electric motors.

These axial movement mechanism 24, the movement mechanism 25 in the direction orthogonal to the axis, and the masks 11 to 16 described above.
Each drive motor 21 is controlled by a central controller (not shown).
It is comprehensively controlled by electrical signals output from the 6 masks 11 to 16, and a signal is output indicating which pattern of the six masks 11 to 16 is located on which rotation on the article. Then, the mask having the pattern 19 to be printed is rotated, and the printed pattern 19 is inserted into the through hole 2.
Stops at position 3. At this time, the other five masks were also rotated at the same time, leaving the circular hole 17 as a space.
It stops when a reaches the position where it overlaps with the printed pattern 19. On the other hand, the moving mechanism 25 in the orthogonal direction
The entire mask portion 5 is moved in the left-right direction in FIG. 2 depending on which circumference the pattern 19 to be printed is on, and the pattern 19 to be printed is positioned within the path through which the laser beam 3 passes. . Further, the mask portion 5 is moved forward and backward in the axial direction by the axial movement mechanism 24, and is moved to a predetermined position between the laser oscillator 1 and the condenser lens 6. In this way, the pattern 1 to be printed by moving the mask part 5 in the axial direction
By always keeping the distance between the mask 9 and the laser oscillator 1 and the condensing lens 6 constant, high-quality printing can be performed.

In addition, in this example, masks 11 to 16
Although the number of masks is set to six, no matter how many masks there are, the distance from the laser oscillator 1 can always be kept constant by the axial movement mechanism 24. Furthermore, if the circular holes 17 formed in each mask are on only one circumference, it goes without saying that the moving mechanism 25 in the direction orthogonal to the axis is not necessary.

As described above, according to the present invention, the distance between the laser oscillator and the condensing lens of the printing pattern to be printed on the article can always be kept constant, so that high-quality printing can be performed.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a partially sectional front view, and FIG. 2 is a −-
3 is a sectional view taken along the line - in FIG. 2. FIG. 3... Laser beam, 11-16... Mask, 1
7... Pattern, 24... Axial direction (progressing direction of the laser beam) movement mechanism, 25... Orthogonal direction movement mechanism.

Claims (1)

[Claims] 1. A plurality of masks each having a pattern of a predetermined shape that allows transmission of a laser beam are arranged in a superimposed manner in the direction in which the laser beam travels, and any one of the above-mentioned patterns is formed in the direction of the laser beam. In a laser printing device that prints on the surface of an object by imparting a pattern to be printed on a laser beam selectively facing into a passageway, these mask groups are placed on the bottom surface of a case that supports the above mask groups so that the laser beam advances. Laser printing characterized in that a moving mechanism is provided for moving forward and backward along the direction, and the moving mechanism is configured to adjust and move a mask on which a pattern to be printed located in the laser beam path is formed to a predetermined position. Device. 2. The laser printing device according to claim 1, wherein a moving mechanism for moving the mask group in a direction perpendicular to the traveling direction of the laser beam is provided on the lower surface of the case supporting the mask group.