JP3311452B2 - Scanning laser mark device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking device for forming a mark such as a character, a symbol or a figure on a target by irradiating the target with a laser beam, and more particularly to a scanning laser mark. is there.

[0002]

2. Description of the Related Art A scanning laser mark device scans a laser beam in a predetermined area and irradiates the surface of an object such as a part or a product with the laser beam (for example, see Japanese Patent Application Laid-Open No. 64-11083). Gazette). In this type of scanning laser marking device, a conveyor for continuously transporting an object is often provided.In this case, the object being transported by the conveyor is irradiated with a laser, and in consideration of the speed of the conveyor, It is necessary to set the scanning speed. That is, it is necessary to finish printing (marking) while the target object is present in the laser beam irradiation area. However, it is difficult to set a scanning speed that makes maximum use of the time during which the laser beam can be irradiated, and the scanning speed is usually set to an unnecessarily high scanning speed.

[0003]

As described above, when the scanning speed is high, the position of the spot of the laser beam is shifted with respect to the target position due to the delay of the optical system. Inevitably, the quality of printing deteriorates. Further, since the irradiation time of the laser beam per unit area is shortened, it is necessary to increase the output of the laser.

[0004] Therefore, from this viewpoint, it is preferable that the scanning speed be as low as possible. That is, it is preferable to set the scanning speed as low as possible within a range in which necessary printing can be performed.

The present invention has been made in view of the above problems, and provides a scanning laser mark device capable of setting a slow scanning speed within a range in which necessary printing can be performed, that is, capable of setting an appropriate scanning speed. The purpose is to do.

[0006]

In order to achieve the above object, an invention according to claim 1 includes an area storage section for storing a predetermined area to be irradiated with a laser beam, and an area storage section upstream of the area in the conveyance direction. A start point coordinate storage unit that stores the coordinates of the irradiation start point, an end point coordinate storage unit that stores the coordinates of the irradiation end point downstream in the transport direction in the area, and stores the coordinates of a mark reference point that is a reference for the mark. Mark reference point storage unit, and a speed setting means for setting a scanning speed for starting printing when the mark reference point reaches the irradiation start point and ending printing when the mark reference point reaches the irradiation end point. I have.

The principle of the first aspect of the present invention will be described with reference to FIG. Now, a work (object) W shown in FIG.
In the case of printing the mark M composed of “AIU”, FIG.
(B) As shown in FIG.
And stores the coordinates of the ₁ ~ O _3. On the other hand, allowed to store the coordinates of an irradiation start point S _T upstream in (target) area A _T of FIG. 3 (c). In addition, the coordinates of the downstream irradiation end point E in the (target) area _AT are stored. Thus each point O ₁ ~O _3, S _T, after pre-stored coordinates of E,
Conveying the workpiece W in the direction of arrow B, the reference point O ₁ of the upstream side starts printing when it reaches the irradiation start point S _T, 3
As shown in (d), the scanning speed at which printing is completed when the downstream reference point O ₃ reaches the irradiation end point E is set. With this setting, printing can be performed while the work W moves a long distance (a + b), so that the scanning speed can be reduced as compared with the case where the scanning speed is fixed at a constant high speed. .

According to a second aspect of the present invention, there is provided a measuring means for measuring a time required for printing at a reference scanning speed as a reference,
A scanning speed calculating means for calculating an actually adopted individual scanning speed based on the measured measurement time, the target time for printing, and the reference scanning speed.

The principle of the present invention will be described with reference to FIG. When the individual scanning speed S is set so as to perform printing in the same time as the target time T, the following (1) is set between the target time T, the individual scanning speed S, the measurement time T _0, and the reference scanning speed S _0. The relationship of the formula is established. S · T = S ₀ · T ₀ (1) On the other hand, the target time T is, for example, the time during which the work W in FIGS. 3C and 3D moves within the (target) area _AT at the transport speed v. Therefore, it can be obtained by the following equation (2). T = (a + b) / v (2) Accordingly, the individual scanning speed S can be obtained based on the target time T, the reference scanning speed S ₀ , and the measurement time T ₀ . Here, the target time T changes for each mark pattern, but by setting the target time T to a large value within an allowable range, the individual scanning speed S is reduced to the reference scanning speed S.
It can be set to a value smaller than ₀ .

[0010] According to a third aspect of the present invention, there is provided a maximum area storage unit for storing a maximum printable area, a target area storage unit for storing a target area included in the maximum area and smaller than the maximum area. Speed setting means for setting a scanning speed at which printing is completed in the target area.

The principle of the third aspect of the present invention will be described with reference to FIG. Maximum area A _M printable is larger than the target area A _T of the inner, the outer target area A _T, because the laser light is irradiated obliquely, the distance to the laser beam spot becomes long. Therefore, target area A
Outside _T , the focus is blurred and the energy per unit area is small. Therefore, by terminating the print within the target area A _T, i.e., by printing in the target area A _T is previously set in the scanning speed to finish, the printing quality is improved. On the other hand, if the transport speed varies, printing may not be performed in the target area _AT . However, also in this case, the target area A
_{Since the} maximum area A _M is provided outside _T , the printing itself can be performed in the maximum area A _M although the quality is slightly lowered. Therefore, if the scanning speed is set so that the printing is completed just by the time when the work W passes through the target area _AT , the scanning speed can be reduced, and even if there is a slight error, the maximum can be obtained. it is possible to reliably perform printing within the area a _M.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG.
, The laser oscillator 1 is, for example, a CO ₂ laser that oscillates with a current from the drive power supply circuit 2 and emits a laser beam L. The laser light L emitted from the laser oscillator 1 is reflected by a pair of carbano mirrors 3a and 3b, and then condensed by a condensing lens 4.
The surface of the work (object) W is irradiated. The two carbano mirrors 3a and 3b constitute a scanning optical system 3, and are driven by an optical system driving device 5 including a pair of carbanometers 5a and 5b. Thereby, the laser light L
Is scanned in the maximum area (irradiation area) in A _M, it is irradiated onto the surface of the work W being conveyed, to mark (printed) on the work W by the energy of the laser beam. Incidentally, the work W by the conveying device 6, such as a conveyor, while being transported to the maximum area A _M is conveyed in the B direction, is detected by the workpiece detection device 7.

Next, the main part of the present invention will be described.
In FIG. 2, the laser mark device includes a control device 8 composed of a microcomputer and an input device 9.
The control device 8 includes a CPU 10 and a memory 20. The CPU 10 includes a control unit 11, a relative coordinate calculation unit 12, a speed setting unit 13, and a timer unit (measurement unit) 14. On the other hand, the memory 20 includes a mark storage unit 27, a mark reference point storage unit 21, a maximum area storage unit 22, a target area storage unit 23, and a start point coordinate storage unit 2.
4, an end point coordinate storage unit 25 and a scanning speed storage unit 26 are provided. An interface (not shown) is interposed between the control device 8 and the input device 9.

[0014] above the mark storing section 27 and the mark reference point storage unit 21, respectively, and FIG. 3 (b) mark reference point O ₁ of the coordinates and the mark M corresponding to the shape of the mark M ~
The coordinates of O ₃ are input from the input device 9 in FIG. 2 and stored.

FIG. 3 shows the maximum area storage section 22.
The coordinates of the maximum printable area A _{M in} (c) are stored. On the other hand, in the target area memory 23 of FIG. 2 are included in the maximum area A _M of FIG. 3 (c), and a small coordinates of the target area A _T is stored than the maximum area A _M. The target area A _T is, for example, a square having a side c and is set concentric with the maximum area A _{M. When} printing is performed in this range, high-quality printing with almost no defocus is performed. It is an area where you can do it.

[0016] the starting point coordinate storing section 24 of FIG. 2, the maximum area upstream coordinates of an irradiation start point S _T in the transport direction B in A _M in FIG. 3 (c) are stored. On the other hand, the above-mentioned end point coordinate storing section 25 of FIG. 2, a downstream coordinate of the irradiation end point E of the conveying direction B in the maximum area A _M in FIG. 3 (c) are stored.

The scanning speed storage section 26 in FIG. 2 stores one reference scanning speed S ₀ and a plurality of individual scanning speeds S. The reference scanning speed S ₀ is set to, for example, the maximum scanning speed of the device. The individual scanning speed S is an optimal scanning speed according to the type of the work W, that is, an individual mark pattern.
The speed is set by the speed setting means 13.

The relative coordinate calculating means 12 actually calculates the coordinates of each mark M and the mark reference points O _{1 to} O ₃ in FIG. 3B read from the mark storage section 27 and the mark reference point storage section 21. 3 (c) is converted into relative coordinates for irradiation in the target area _AT . This coordinate conversion is calculated based on the scanning speed and the transport speed v of the transport device 6 (FIG. 1). The control unit 11 of FIG. 2 controls the driving power supply circuit 2 and the optical system driving device 5 to control the laser beam L (FIG. 1) at a position corresponding to the relative coordinates at the individual scanning speed S or the reference scanning speed S ₀ . ).

The speed setting means 13 determines the individual scanning speed S
Is provided with a scanning speed calculating means 13a for calculating
Mark reference point O ₁ of the upstream side starts printing when it reaches the irradiation start point S _T in (c), the downstream side of the mark reference point O
_The individual scanning speed S is set so that printing is completed when ₃ reaches the irradiation end point E. Further, in this embodiment, the speed setting means 13 (FIG. 2) is printed instead maximum area A _M is, to end at the target area A _T, to set the individual scanning speeds S.

Next, a specific setting method of the individual scanning speed S will be described. First, the scanning speed storage unit 26 shown in FIG.
The reference scanning speed S ₀ is read out from, and the required time T ₀ when the printing is performed at the reference scanning speed S ₀ is measured by operating the optical system driving device 5 for the work W to be actually printed.
The measured measurement time T ₀ is measured by the timer means 14. At this time, it is preferable that the laser beam is not emitted from the laser oscillator 1, but the laser beam may be emitted.

Meanwhile, actually, after the mark reference point O ₁ of the upstream of the work W shown in FIG. 3 (c) reaches the irradiation start point S _T, it is downstream of the mark reference point O ₃ reaches the irradiation end point E Since printing is performed before the printing, the target printing time T is expressed by the above-mentioned equation (2). T = (a + b) / v (2) where a + b is the distance the work W moves during printing a + b = a + c−d d is the maximum width of one character pattern

The relationship of the following equation (1) holds between the target time T, the measurement time T ₀ , the individual scanning speed S, and the reference scanning speed S ₀ . ST = S ₀ · T ₀ (1) The scanning speed calculating means 13a of FIG. 2 calculates the individual scanning speed S based on the above equations (1) and (2). The calculated individual scanning speed S is stored in the individual scanning speed storage unit 13b composed of a register. Note that the individual scanning speed S is stored in the scanning speed storage unit 26 as needed.

Next, the operation of the above configuration will be described. First, before actually printing, the individual scanning speed S is obtained in advance by the above-described method. Thereafter, the workpiece W is transported in the transport direction B by the transport device 6 of FIG. When the workpiece W is loaded to the maximum area A _M, the workpiece detector 7 detects the workpiece W, the workpiece detection signal is output to the CPU 10 (FIG. 2). CPU 10 (FIG. 2) knows that on the basis of the detection signal of the work detector 7 is marked reference point 0 ₁ shown in FIG. 3 (c) reaches the irradiation start point S _T, workpiece W enters the maximum area A _M after, the mark reference point O ₁ of the upstream reaches the irradiation start point S _T, together emit a laser beam to the laser oscillator 1 through the driving power source circuit 2 in FIG. 2, through the optical system driving device 5 scans Printing is started by scanning the optical system 3 (FIG. 1). As the scanning speed at this time, the individual scanning speed S corresponding to the type of the work W and the print content (mark pattern) is read in advance from the scanning speed storage unit 26 to the CPU 10 and selected. Thus, printing is started when the mark reference point O ₁ of the upstream shown in FIG. 3 (c) reaches the irradiation start point S _T, as shown in FIG. 3 (d), the ends irradiation mark reference point O ₃ of the downstream When the point E is reached, the printing is completed, and a mark M such as “Aiu” is printed on the work W.

When printing is performed by scanning the spot of the laser beam only near the center of the target area _AT ,
It is necessary to finish printing while the work W moves a distance of (a + d). In contrast, when the laser mark device, the individual scanning speeds S in performing the actual printing starts printing when the mark reference point O ₁ of the upstream side reaches the irradiation start point S _T, the downstream Printing ends when the mark reference point O ₃ reaches the irradiation end point E. Therefore, since the moving distance of the work W during printing becomes longer as (a + b), that is, the printing time becomes longer as T = (a + b) / v, the individual scanning speed S can be reduced. As a result, the quality of printing is improved.

Here, it is not easy for the operator to obtain the speed at which printing is completed during the target time T by desk calculation. On the other hand, in this laser mark device, the timer means 14 (FIG. 2) measures the required time (measurement time) T ₀ when the actual printing is performed at the reference scanning speed S ₀ , and the above-described (1), The scanning speed calculating means 13a (FIG. 2) calculates the individual scanning speed S required for printing each mark pattern based on the equation (2). Therefore, the individual scanning speed S can be easily obtained, and printing can be performed at a low scanning speed according to the mark pattern, so that the printing quality is improved. .

It should be noted that the target time T does not necessarily need to be determined by the above-described equations (1) and (2), but may be determined based on the measurement time T ₀ , the reference scanning speed S ₀ and the individual scanning speed S. For example, the individual scanning speed S may be slightly higher than the scanning speed obtained from the expressions (1) and (2) in consideration of the speed error of the transport device 6 and the like.

In the first embodiment, the target area A _T is provided inside the maximum area A _M so that printing can be performed only by scanning the target area A _T. Thus, outside the target area A _T away from the center of the maximum area A _M, is not performed printing principle. As a result, the blurring of the focus is reduced, and the quality of printing is improved.

FIG. 4 shows a modification in which the transport direction B changes. FIG. 4A shows a case where the transport direction B is set in a direction opposite to that in FIG. In this case, the mark reference point O
₃ starts printing when it reaches the irradiation start point S _T, the mark reference point O ₁ has finished printing when it reaches the irradiation end point E.

FIG. 4B shows a case where the transport direction B is set to a direction different from that of FIG. 3 by 90 °. In this case, printing is started when the mark reference point O ₁ reaches the irradiation start point S _T, the mark reference point O ₄ is finished printing when it reaches the irradiation end point E. In the case of FIG.
The individual scanning speed S is obtained by the following equation (3). S = S ₀ · T ₀ · {v / (a ₁ + b ₁ )} (3) where a ₁ + b ₁ : distance traveled by the workpiece W during printing a ₁ + b ₁ = a ₁ + c-h h: Maximum height of one character pattern

FIG. 4C shows a case where the transport direction B is set in a direction opposite to that of FIG. 4B. In this case, printing is started when the mark reference point O ₄ reaches the irradiation start point S _T, the mark reference point O ₁ has finished printing when it reaches the irradiation end point E.

[0031] In the first embodiment of FIG. 3, it is provided with the target area A _T in the maximum area A _M, claim 1,
According to the second aspect, as shown in FIGS. 4B and 4C, only the maximum area A _M may be provided without storing the target area _AT, and may be stored.

FIG. 5 shows a second embodiment. The second embodiment shows an embodiment in which the transport speed v is not uniform or unknown. In this case, a position sensor 30 indicated by a two-dot chain line in FIG. 1 is provided. The position sensor 30 outputs the position pulse signal shown in FIG. 5A every time the transport surface moves by a predetermined set distance, regardless of the transport speed v of the transport device 6.

Assuming that the intervals at which the position pulse signal is generated are t ₁ , t _2, ..., The work W shown in FIG.
As shown in (c), the time T required to move by a predetermined moving distance L = a + d, that is, the target time T is obtained by the following equation (4). T = t ₁ + t ₂ +... + T _{L / L1} (4) where L1 is the movement amount of the work W per pulse.

On the other hand, since the transport speed v is not uniform, printing is performed during the moving distance L = (a + d) in FIG. 5C, which is smaller than the moving distance L = (a + b) in FIG. 3D. Set to end just. As a result, even if the transport speed v increases, a margin is provided by the distance (b-d).
In this case, the individual scanning speed S is obtained by the following equation (5). S = S ₀ · T ₀ / (t ₁ + t ₂ +... + T _{L / L1} ) (5)

FIG. 6 shows the second embodiment of FIG.
A modified example when the angle is different by 0 ° is shown. In this modification, FIG.
Mark reference point O ₁ of (a) starts printing when it reaches the irradiation start point S _T, the mark reference point O ₇ in FIG. 6 (b) terminates the printing when it reaches the irradiation end point E. in this case,
The individual scanning speed S is obtained by the following equation (6). S = S ₀ · T ₀ / (t ₁ + t ₂ +... + T _{L / L1} ) (6) where L = a ₁ + h

In each of the above embodiments, during printing,
Although the work W in FIG. 1 has moved, the invention of claim 2 is also applied to a case where printing is performed while the work W is stationary. For example, if the carrying device 6 has a function of transporting the workpiece W intermittently, after the workpiece W is carried into the maximum area A _M, the conveying device 6 is stopped for a certain time, performs printing in this stop Alternatively, an optimum scanning speed may be set according to the stop time of the transport device 6. In this case, the target time T is set to a value equal to or shorter than the stop time of the work W. In addition, the present invention is also applied to a case where an automatic machine sets the optimum scanning speed in accordance with the cycle time of loading when the workpieces W are loaded one by one. As is clear from these descriptions, the target time T may be set to be equal to or shorter than the allowable time allowed for printing.

Further, in each of the above embodiments, a plurality of mark reference points O _{1 to} O ₁ are added to one mark pattern “AIU” in FIG.
It has been described with _N but the present invention can be applied even when the mark reference point O ₁ is one. Mark reference point O ₁
There the one case, it is sufficient to terminate the printing until the mark reference point O ₁ shown in FIG. 3 (c) reaches the irradiation end point E from reaching the irradiation start point S _T.

The moving distance L is (a + b) in the first embodiment of FIG. 3, and (a + b) in the second embodiment of FIG.
However, in the present invention, the moving distance L is, for example, a +
It may be set appropriately within the range of d ≦ L ≦ a + b.

[0039]

As described above, according to the first aspect of the present invention, printing is started when the mark reference point reaches the irradiation start point on the upstream side, and the mark reference point is set on the irradiation end point on the downstream side. Since the individual scanning speed is set so that the printing is terminated when the object reaches, printing may be performed while the object moves over a long distance. Therefore, since the scanning speed can be reduced as compared with the case where the scanning speed is fixed to a constant high speed, an appropriate scanning speed can be set. That is, a high-quality mark can be formed with a low laser output and within an allowable time.

According to the second aspect of the present invention, the time required for actual printing is measured using the reference scanning speed, and the individual scanning speed is obtained based on the measured time, the reference scanning speed, and the target time. In addition, high-quality printing can be performed using an appropriate individual scanning speed, and the individual scanning speed can be easily obtained.

According to the third aspect of the present invention, since the target area is provided inside the maximum printable area, high quality printing can be normally performed by performing printing in the target area. In addition, printing can be performed when printing needs to be performed outside the target area, for example, when the scanning speed is not uniform.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a laser marking device showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a control device.

FIG. 3A is a plan view showing a printed work,
(B) is a plan view showing a mark pattern, (c) and (d).
Is a plan view showing a printing operation.

FIG. 4 is a plan view showing a printing method when a transport direction and a mark pattern change.

FIG. 5 is a diagram illustrating a printing method when the transport speed is uneven.

FIG. 6 is a diagram illustrating a printing method when the transport direction changes.

[Explanation of symbols]

13: speed setting means 13a: scanning speed calculating means 14: measuring means (timer means) 21: mark reference point storage section 22: maximum area storage section 23: target area storage section 24: start point coordinate storage section 25: end point coordinates Storage unit 26: (Reference and individual) scanning speed storage unit A _M : Maximum area A _T : Target area B: Transport direction E: Irradiation end point S _T : Irradiation start point S: Individual scanning speed S ₀ : Reference scanning speed O _{1 to} O ₃ : mark reference point W: work L: laser beam

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 26/00-26/08

Claims (3)

(57) [Claims] 1. A scanning laser mark device that scans a laser beam within a predetermined area and irradiates the surface of the object being conveyed with the laser beam to form a mark on the surface of the object. An area storage unit that stores an area; a start point coordinate storage unit that stores the coordinates of an irradiation start point upstream in the transport direction in the area; and an end point coordinate storage that stores coordinates of an irradiation end point downstream in the transport direction in the area. A mark reference point storage unit for storing coordinates of a mark reference point serving as a reference of the mark, and printing is started when the mark reference point reaches the irradiation start point, and when the irradiation end point is reached. A scanning laser mark device comprising a speed setting means for setting a scanning speed at which printing is completed. 2. A scanning laser mark device that scans a laser beam within a predetermined area and irradiates the surface of the object with the laser beam to form a mark on the surface of the object. Measuring means for measuring a time required for printing at a scanning speed; and a scanning speed for calculating an individual scanning speed to be actually employed based on the measured measuring time, a target time for printing, and the reference scanning speed. A scanning laser mark device comprising a calculating means. 3. A scanning laser mark device which scans a laser beam within a predetermined area and irradiates the surface of the object being conveyed with the laser beam to form a mark on the surface of the object. A maximum area storage section for storing a maximum possible area; a target area storage section for storing a target area included in the maximum area and smaller than the maximum area; and a scanning speed for ending printing in the target area. And a speed setting means for setting a speed.