Data processing: generic control systems or specific application – Generic control system – apparatus or process – Digital positioning
Reexamination Certificate
2000-02-23
2002-11-26
Black, Thomas (Department: 2121)
Data processing: generic control systems or specific application
Generic control system, apparatus or process
Digital positioning
C700S166000, C219S121600, C219S121780, C219S121820
Reexamination Certificate
active
06487460
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a laser marker moving irradiation points of laser beams using a galvanometer scanner and printing a desired mark composed of characters, figures and/or symbols on an object on the basis of movement loci of the irradiation points.
2. Description of the Prior Art
FIG. 8
shows a conventional laser marker of the above-described type. The shown laser marker comprises a laser oscillator
10
producing laser beams, a galvanometer scanner
11
including a pair of galvanometer mirrors
12
a
and
12
b
reflecting the laser beams produced from the laser oscillator
10
, and a condensing lens
15
condensing the reflected laser beams so that the laser beams are irradiated onto an object on which a mark is to be printed. Electric motors
13
a
and
13
b
are provided for changing angles of reflection of the mirrors
12
a
and
12
b
respectively. The laser beam is scanned horizontally in
FIG. 8
or in the X direction by the mirror
12
a
, whereas the laser beam is scanned in the Y direction generally perpendicular to the X direction by the mirror
12
b
. A control device
14
is provided for controlling the angles of reflection of the mirrors
12
a
and
12
b
and the laser oscillator
10
so that the same is turned on and off. The control device
14
comprises a CPU
20
as a main component thereof as shown in
FIG. 9. A
memory
21
and an input device
22
are connected to the CPU
20
.
The memory
21
stores graphic data concerning marks which can be designated prior to start of a printing operation and data of predetermined computing expressions or formulas. The graphic data includes coordinate data concerning both end points of respective component lines of each mark. More specifically, for example, graphic data of mark “A” includes coordinate data of end points T
1
to T
5
of component lines L
1
, L
2
and L
3
, as shown in FIG.
10
A. Furthermore, the computing expressions include those for obtaining subdivided points and those for obtaining compensation. The computing expressions for subdivided points are provided for obtaining coordinate data of a plurality of locations obtained by subdividing the component lines of the mark on the object on the basis of coordinate data of the graphic data. For example, concerning the mark “A,” coordinate data of a plurality of locations (points P
1
, P
2
, P
3
, and so on in
FIG. 10A
) is obtained by subdividing the component lines L
1
to L
3
as shown in FIG.
10
A. The computing expressions for compensation are used to compensate the distortion of the laser beam due to an aberration of the lens
15
.
The character “A” is designated by the input device
22
when it is to be printed by the conventional laser marker. The CPU
20
of the control device
14
then carries out the following steps 1 to 4:
Step 1: The CPU
20
retrieves graphic data concerning a plurality of marks stored in the memory
21
to input the graphic data (coordinate data of end points T
1
to T
5
) corresponding to the designated mark “A.”
Step 2: The CPU
20
reads out the computing expressions for subdivided points from the memory
21
to compute coordinate data of a plurality of locations subdividing the component lines L
1
, L
2
and L
3
of the mark “A” on the basis of the coordinate data of end points T
1
to T
5
.
Step 3: The CPU
20
reads out the computing expressions for compensation from the memory
21
to compensate distortion in the coordinate data of a plurality of the locations on the basis of the read expressions.
Step 4: The CPU
20
delivers the compensated coordinate data to the galvanometer scanner
11
cyclically for a predetermined period and further delivers an on-off signal to the laser oscillator
10
.
Upon receipt of the coordinate data, the galvanometer scanner
11
scans irradiation points of the laser light produced from the laser oscillator
10
in such a manner that locations indicated by a series of coordinate data are connected together. As a result, the irradiation points are moved in the direction of arrow in
FIG. 10B
so that the desired mark “A” is printed on the object W. Japanese Unexamined Patent Application Publication No. 11-28586 (1999) discloses a laser marker of the type described above.
In the conventional laser marker, the memory stores only the coordinate data concerning the end points of the component lines of each mark as the data of marks which can be designated. Accordingly, the coordinate data is generated during the printing operation as described above. As a result, a printing speed cannot be increased so high since the CPU
20
(control device
14
) needs to ensure a time for generation of coordinate data. Provision of the control device with the CPU of high processing speed type can increase the printing speed. However, the cost for the laser marker is increased with improvement in the performance of the CPU.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a laser marker which can increase the printing speed without a large increase in the cost.
The present invention provides a laser marker scanning laser beams to print a mark on an object, the laser marker comprising a laser oscillator producing laser beams, an input device designating a mark to be printed, a galvanometer scanner successively receiving coordinate data corresponding to a predetermined location on the object, the galvanometer scanner scanning the laser beams produced from the laser oscillator toward the predetermined location on the object on the basis of the coordinate data, a memory storing sets of coordinate data of a multitude of locations on the object, the locations dividing a component line of each of marks which can be designated by the input device, and a control device successively delivering the coordinate data concerning the mark designated by the input device from the memory to the galvanometer scanner.
According to the aforesaid laser marker, the memory stores the sets of coordinate data of a multitude of the locations obtained by dividing the component line of each of the marks on the object with respect to all the marks which can be designated by the input device. Accordingly, the control device need not generate coordinate data during the printing operation and merely delivers the coordinate data from the memory to the galvanometer scanner. Thus, since the conventionally required coordinate data generating time is unnecessary, the coordinate data can be supplied to the galvanometer scanner in a shorter period. Consequently, the printing speed of the laser marker can be improved without a cost increase due to an improvement in the data processing performance of the control device.
REFERENCES:
patent: 4818835 (1989-04-01), Kuwabara et al.
patent: 5021631 (1991-06-01), Ravellat
patent: 5566277 (1996-10-01), Hideshima et al.
patent: 5734412 (1998-03-01), Hasebe et al.
patent: 5966307 (1999-10-01), Lin
patent: 6066829 (2000-05-01), Ishikawa
patent: 6130402 (2000-10-01), Abella et al.
patent: 6239406 (2001-05-01), Onoma et al.
patent: 883277 (1998-09-01), None
patent: 05293678 (1993-11-01), None
patent: 7-33475 (1995-06-01), None
patent: 7-33476 (1995-06-01), None
patent: 11-285586 (1999-02-01), None
Barnes Crystal J.
Black Thomas
Sunx Limited
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