JP7003903B2 - Laser marker - Google Patents

Description

The present disclosure relates to laser markers.

Conventionally, various techniques have been proposed for laser markers that measure the distance to an object to be machined. For example, the technique described in Patent Document 1 below is a distance measuring device, which is a light projecting means for projecting spot light on the surface of an object to be measured, and the object to be measured by receiving the reflected light from the object to be measured. A first light receiving means for outputting a distance signal corresponding to a distance up to, and a second light receiving means for receiving the reflected light from the object to be measured and outputting a correction signal for correcting the variation in the reflectance of the spot light. It is characterized by comprising a light receiving means and a correction means for correcting the distance signal by applying a correction signal from the second light receiving means to the distance signal from the first light receiving means.

According to the description of Patent Document 1 below, a distance measuring device having such a feature is projected when it is used in a laser processing machine and is generated when measuring a distance to a metal surface of an object to be measured. It is said that the problem of deterioration of measurement accuracy due to uneven reflection of light can be solved.

Japanese Unexamined Patent Publication No. 62-62208

However, the processed region on the surface of the object to be measured is not always a flat surface. Therefore, even if the focal position of the laser processing machine is determined based on the distance to the object to be measured measured by the distance measuring device described in Patent Document 1, the surface of the object to be measured depends on the position in the processing area. However, there was a risk that the focal position would be out of the permissible range.

Therefore, the present disclosure has been made in view of the above-mentioned points, and provides a laser marker capable of improving printing accuracy by a processing laser beam.

In the present specification, a laser light source that emits a processing laser beam for printing an object on the processing surface of a processing object and a distance measuring laser that emits a distance measuring laser beam and is reflected by the distance measuring object. By receiving light, a distance measuring unit that measures the distance to the object to be measured, a laser beam for processing, and a laser beam for distance measurement are irradiated onto the processed surface of the object to be processed and scanned. It is equipped with a scanning unit, a variable focus optical system that moves and corrects the focal position of the laser beam for processing, a storage unit that stores the print pattern of the object, and a control unit. Based on this, multiple measurement points are set on the machined surface of the object to be machined, and the distance between the measurement point and the distance measuring part obtained by reflecting the distance measuring laser beam at the multiple measuring points is measured. As a distance, it is stored in the storage unit in association with the measurement point, and when the laser beam for processing is scanned on the processing surface of the object to be processed based on the print pattern of the object, the print pattern, measurement point, and measurement of the object are performed. The focal position of the machining laser beam is corrected based on the distance, and the multiple measurement points are at the irradiation positions where the machining laser beam is applied onto the machined surface of the machined object based on the print pattern of the object. The control unit is sandwiched between two adjacent measurement points when the difference in measurement distance between two adjacent measurement points on the machined surface of the object to be machined exceeds the first reference value among a plurality of measurement points. Disclosed is a laser marker characterized in that a measurement point is added at a position where a straight line connecting two adjacent measurement points and an irradiation position overlap in the vicinity of the center of the space.

According to the present disclosure, the laser marker corrects the focal position of the laser beam for machining by using the distance measured based on the print pattern of the object when printing the object on the machined surface of the object to be machined. Therefore, it is possible to improve the printing accuracy by the laser beam for processing.

It is a figure which showed the schematic structure of the laser marker of this embodiment. It is a block diagram showing the electrical structure of the laser marker. It is a figure which showed the schematic structure of the laser marker. It is a figure showing between the fθ lens and the machined surface of a machined object. It is a figure which represented the 1st data table. It is the figure which represented the 2nd data table. It is a figure showing between the fθ lens and the machined surface of a machined object. It is a figure which showed the setting example of the measurement point on the machined surface of the machined object. It is a figure which showed the setting example of the measurement point on the machined surface of the machined object. It is a flowchart showing each process performed by the laser marker.

Hereinafter, the laser marker of the present disclosure will be described with reference to the drawings based on the embodied embodiment. In FIGS. 1 to 3 used in the following description, a part of the basic configuration is omitted, and the dimensional ratio and the like of each drawn part are not always accurate. In the following description, the vertical direction is as shown in FIGS. 1, 3, 4, and 7.

[1. Schematic configuration of laser marker]
First, a schematic configuration of the laser marker 1 of the present embodiment will be described with reference to FIGS. 1 and 2. The laser marker 1 of this embodiment is composed of a print information creating unit 2 and a laser processing unit 3. The print information creating unit 2 is composed of a personal computer or the like.

The laser processing unit 3 performs marking (printing) processing by two-dimensionally scanning the laser beam P on the processing surface 8 of the processing object 7. The laser processing unit 3 includes a laser controller 6.

The laser controller 6 is composed of a computer and is connected to the print information creating unit 2 so as to be capable of bidirectional communication. The laser controller 6 drives and controls the laser processing unit 3 based on the print information, control parameters, various instruction information, and the like transmitted from the print information creation unit 2.

The schematic configuration of the laser processing unit 3 will be described. The laser processing unit 3 includes a laser oscillation unit 12, a guide light unit 15, a first dichroic mirror 101, an optical system 70, a TOF (Time of Flight) sensor 103, a second dichroic mirror 105, a galvano scanner 18, an fθ lens 19, and the like. It is covered with a housing cover having a substantially rectangular shape (not shown).

The laser oscillation unit 12 is composed of a laser oscillator 21 and the like. The laser oscillator 21 is composed of a CO2 laser, a YAG laser, or the like, and emits a laser beam P. The light diameter of the laser beam P is adjusted (for example, enlarged) by a beam expander (not shown).

The guide light unit 15 is composed of a visible semiconductor laser 28 or the like. The visible semiconductor laser 28 emits a visible laser beam Q, which is visible interference light, for example, a red laser beam. The visible laser beam Q is made into parallel light by a lens group (not shown), and for example, an image of a print pattern to be marked (printed) by the laser beam P or a rectangular image surrounding the image is processed as an object 7. It is projected onto the machined surface 8 of.

The wavelength of the visible laser light Q is different from the wavelength of the laser light P. In the present embodiment, for example, the wavelength of the laser beam P is 1064 nm, and the wavelength of the visible laser beam Q is 650 nm.

In the first dichroic mirror 101, almost all of the incident laser beam P is transmitted. Further, in the first dichroic mirror 101, the visible laser light Q is incident at an incident angle of 45 degrees at a substantially central position through which the laser light P is transmitted, and is reflected on the optical path of the laser light P at a reflection angle of 45 degrees. Ru. The reflectance of the first dichroic mirror 101 has a wavelength dependence. Specifically, the first dichroic mirror 101 is surface-treated with a multilayer film structure of a dielectric layer and a metal layer, has a high reflectance with respect to the wavelength of visible laser light Q, and other than that. It is configured to transmit most (99%) of the wavelength of light.

The alternate long and short dash line in FIG. 1 indicates the optical axis 10 of the laser beam P and the visible laser beam Q. Further, the direction of the optical axis 10 indicates the path direction of the laser beam P and the visible laser beam Q.

The optical system 70 includes a first lens 72, a second lens 74, and a moving mechanism 76. In the optical system 70, the laser beam P and the visible laser beam Q that have passed through the first dichroic mirror 101 enter the first lens 72 and pass therethrough. At that time, the light diameters of the laser beam P and the visible laser beam Q are reduced by the first lens 72. Further, the laser beam P and the visible laser beam Q that have passed through the first lens 72 enter the second lens 74 and pass therethrough. At that time, the laser beam P and the visible laser beam Q are made into parallel light by the second lens 74. The moving mechanism 76 includes an optical system motor 80, a rack and pinion (not shown) that converts the rotational motion of the optical system motor 80 into linear motion, and the like, and is second by controlling the rotation of the optical system motor 80. The lens 74 is moved in the path direction of the laser light P and the visible laser light Q.

The moving mechanism 76 may be configured to move the first lens 72 instead of the second lens 74, or the first lens so that the distance between the first lens 72 and the second lens 74 changes. It may be configured to move both the 72 and the second lens 74.

The TOF sensor 103 is a TOF type sensor that measures the time until the emitted ranging laser beam returns and converts the measured time into a distance. In the second dichroic mirror 105, almost all of the incident laser light P and visible laser light Q are transmitted. A detailed description of the TOF sensor 103 and the second dichroic mirror 105 will be described later.

The galvano scanner 18 two-dimensionally scans the laser beam P and the visible laser beam Q that have passed through the second dichroic mirror 105. In the galvano scanner 18, the galvano X-axis motor 31 and the galvano Y-axis motor 32 are attached so that their respective motor axes are orthogonal to each other, and the scanning mirrors 18X and 18Y attached to the tip of each motor axis are inside. They are facing each other. Then, the laser light P and the visible laser light Q are two-dimensionally scanned by rotating the scanning mirrors 18X and 18Y under the rotation control of the motors 31 and 32. The two-dimensional scanning directions are the X direction and the Y direction.

The fθ lens 19 collects the laser beam P and the visible laser beam Q two-dimensionally scanned by the galvano scanner 18 on the processing surface 8 of the processing object 7. Therefore, the laser light P and the visible laser light Q are two-dimensionally scanned in the X direction and the Y direction on the machined surface 8 of the machined object 7 by the rotation control of the motors 31 and 32, respectively.

Next, the circuit configurations of the print information creating unit 2 and the laser processing unit 3 constituting the laser marker 1 will be described with reference to FIG. First, the circuit configuration of the laser processing unit 3 will be described.

As shown in FIG. 2, the laser processing unit 3 includes a laser controller 6, a galvano controller 35, a galvano driver 36, a laser driver 37, a semiconductor laser driver 38, an optical system driver 78, a TOF sensor 103, and the like. There is. The laser controller 6 controls the entire laser processing unit 3. A galvano controller 35, a laser driver 37, a semiconductor laser driver 38, an optical system driver 78, a TOF sensor 103, and the like are electrically connected to the laser controller 6. Further, an external print information creation unit 2 is connected to the laser controller 6 so as to be capable of bidirectional communication, and each information transmitted from the print information creation unit 2 (for example, print information and control parameters for the laser processing unit 3) is connected. , Various instruction information from the user, etc.) can be received.

The laser controller 6 includes a CPU 41, a RAM 42, a ROM 43, and the like. The CPU 41 is an arithmetic unit and a control device that controls the entire laser processing unit 3. The CPU 41, RAM 42, and ROM 43 are connected to each other by a bus line (not shown), and data is exchanged with each other.

The RAM 42 is for temporarily storing various calculation results calculated by the CPU 41, (XY coordinates) data of the print pattern, and the like.

The ROM 43 stores various programs. For example, a program that calculates XY coordinate data of a print pattern based on the print information transmitted from the print information creation unit 2 and stores it in the RAM 42 is stored. There is. In addition to the above-mentioned programs, various programs include, for example, the thickness, depth and number of print patterns corresponding to the print information input from the print information creation unit 2, the laser output of the laser oscillator 21, and the laser light. There is a program that stores various control parameters indicating the laser pulse width of P, the speed at which the laser beam P is scanned by the galvano scanner 18, and the like in the RAM 42. Further, the ROM 43 stores data such as a start point, an end point, a focal point, and a curvature of the font of each character composed of a straight line and an elliptical arc for each type of font.

The CPU 41 performs various operations and controls based on various programs stored in the ROM 43.

The CPU 41 uses the galvano controller to obtain XY coordinate data of the print pattern calculated based on the print information input from the print information creation unit 2, galvano scanning speed information indicating the speed at which the laser beam P is scanned by the galvano scanner 18, and the like. Output to 35. Further, the CPU 41 outputs to the laser driver 37 the laser output of the laser oscillator 21 set based on the print information input from the print information creation unit 2, and the laser drive information indicating the laser pulse width of the laser beam P and the like. ..

The CPU 41 outputs an on signal instructing the start of lighting of the visible semiconductor laser 28 or an off signal instructing the extinguishing of the visible semiconductor laser 28 to the semiconductor laser driver 38.

The galvano controller 35 drives and rotates the galvano X-axis motor 31 and the galvano Y-axis motor 32 based on the information input from the laser controller 6 (for example, XY coordinate data of the print pattern, galvano scanning speed information, etc.). The speed and the like are calculated, and the motor drive information indicating the drive angle and the rotation speed is output to the galvano driver 36. The galvano driver 36 drives and controls the galvano X-axis motor 31 and the galvano Y-axis motor 32 based on the motor drive information input from the galvano controller 35, and scans the laser beam P and the visible laser beam Q in two dimensions.

The laser driver 37 drives the laser oscillator 21 based on the laser output of the laser oscillator 21 input from the laser controller 6, the laser drive information indicating the laser pulse width of the laser beam P, and the like. The semiconductor laser driver 38 turns on or turns off the visible semiconductor laser 28 based on the on signal or off signal input from the laser controller 6.

The optical system driver 78 drives and controls the optical system motor 80 based on the information input from the laser controller 6 (for example, a command value described later) to move the second lens 74.

Next, the circuit configuration of the print information creating unit 2 will be described. The print information creation unit 2 includes a control unit 51, an input operation unit 55, a liquid crystal display (LCD) 56, a CD-ROM drive 58, and the like. An input operation unit 55, a liquid crystal display 56, a CD-ROM drive 58, and the like are connected to the control unit 51 via an input / output interface (not shown).

The input operation unit 55 is composed of a mouse, a keyboard, and the like (not shown), and is used, for example, when the user inputs various instruction information.

The CD-ROM drive 58 reads various data, various application software, and the like from the CD-ROM 57.

The control unit 51 controls the entire print information creation unit 2, and includes a CPU 61, a RAM 62, a ROM 63, a hard disk drive (hereinafter referred to as “HDD”) 66, and the like. The CPU 61 is an arithmetic unit and a control device that controls the entire print information creation unit 2. The CPU 61, RAM 62, and ROM 63 are connected to each other by a bus line (not shown), and data is exchanged with each other. Further, the CPU 61 and the HDD 66 are connected to each other via an input / output interface (not shown), and data is exchanged with each other.

The RAM 62 is for temporarily storing various calculation results and the like calculated by the CPU 61. The ROM 63 stores various programs and the like.

The HDD 66 stores various application software programs, various data files, and the like.

[2. Laser light focal position and its correction]
Next, the focal position of the laser beam P and its correction will be described.

As shown in FIG. 1, the laser beam P is emitted from the laser oscillation unit 12. The emitted laser beam P passes through the first dichroic mirror 101. The transmitted laser beam P passes through the first lens 72 and the second lens 74 in the optical system 70. The passed laser beam P passes through the second dichroic mirror 105. The transmitted laser beam P is two-dimensionally scanned by the scanning mirrors 18X and 18Y of the galvano scanner 18. The two-dimensionally scanned laser beam P is incident on the fθ lens 19. The incident laser beam P is focused by the fθ lens 19 and emitted from the fθ lens 19. The emitted laser beam P irradiates the machined surface 8 of the machined object 7.

Hereinafter, the position where the laser beam P should be irradiated on the machined surface 8 of the machined object 7 is referred to as a “scheduled irradiation point”.

If the machined surface 8 of the machined object 7 is a flat surface, the laser beam P is two-dimensionally scanned by the galvano scanner 18 at any position on the machined surface 8 of the machined object 7 by the fθ lens 19. The light is collected on the machined surface 8 of the object 7. However, as shown in FIG. 1, when the machined surface 8 of the object to be machined 7 is inclined even if it is flat, the distance from the reference position related to the position of the fθ lens 19 to the planned irradiation point becomes large. It depends on the position of the object to be machined 7 on the machined surface 8. Therefore, depending on the position of the object to be machined 7 on the machined surface 8, the laser beam P is focused at a position shifted in the vertical direction from that position. Therefore, the laser marker 1 of the present embodiment corrects the focal position of the laser beam P so that it is on the machined surface 8 of the object to be machined 7 by moving it in the vertical direction by the optical system 70. This point is the same even if the machined surface 8 of the object to be machined 7 has a stepped shape.

In FIG. 1, when the laser beam P is vertically incident on the fθ lens 19 (hereinafter, referred to as “vertically incident”), the first lens 72 to the second lens 74 in the optical system 70. The distance is adjusted to the second distance A2. As a result, the second focal position F2 of the laser beam P is placed on the machined surface 8 of the machined object 7.

On the other hand, when the distance from the reference position related to the position of the fθ lens 19 to the scheduled irradiation point is longer than that in the case of vertical incident, the distance from the first lens 72 to the second lens 74 in the optical system 70 is increased. It is adjusted to be longer than the second distance A2. As a result, the focal position of the laser beam P is corrected so as to move downward and be placed on the machined surface 8 of the machined object 7. In FIG. 1, in the optical system 70, the distance from the first lens 72 to the second lens 74 is adjusted from the second distance A2 to the first distance A1 which is longer than the second distance A2. As a result, the focal position of the laser beam P moves from the second focal position F2 to the first focal position F1 below the second focal position F2, and is placed on the machined surface 8 of the object 7 to be machined. Corrected to be placed.

On the other hand, when the distance from the reference position related to the position of the fθ lens 19 to the planned irradiation point is shorter than that in the case of vertical incident, in the optical system 70, from the first lens 72 to the second lens 74. The distance is adjusted to be shorter than the second distance A2. As a result, the focal position of the laser beam P is corrected so as to move upward and be placed on the machined surface 8 of the machined object 7. In FIG. 1, in the optical system 70, the distance from the first lens 72 to the second lens 74 is adjusted from the second distance A2 to the third distance A3, which is shorter than the second distance A2. As a result, the focal position of the laser beam P moves from the second focal position F2 to the third focal position F3, which is upward from the second focal position F2, and is placed on the machined surface 8 of the object 7 to be machined. Corrected to be placed.

Hereinafter, when the focal position of the laser beam P is generically described without distinguishing between the first focal position F1, the second focal position F2, and the third focal position F3, it is referred to as “focal position F”.

Further, the laser marker 1 of the present embodiment measures the distance between the TOF sensor 103 and the planned irradiation point by the TOF sensor 103 in order to make such a correction.

As shown in FIG. 3, in the TOF sensor 103, the range-finding laser beam R is emitted toward the second dichroic mirror 105. In the second dichroic mirror 105, the range-finding laser beam R is incident at an incident angle of 45 degrees and reflected on the optical path of the laser beam P at a reflection angle of 45 degrees. At that time, the optical axis of the range-finding laser beam R coincides with the optical axis 10 of the laser beam P, but may be parallel to each other. The reflectance of the second dichroic mirror 105 has a wavelength dependence in the same manner as that of the first dichroic mirror 101. Specifically, the second dichroic mirror 105 is surface-treated with a multilayer film structure of a dielectric layer and a metal layer, and has a high reflectance with respect to the wavelength of the range-finding laser beam R. It is configured to transmit most (99%) of light of wavelengths other than.

The range-finding laser beam R reflected by the second dichroic mirror 105 is incident on the scanning mirrors 18X and 18Y of the galvano scanner 18. The incident laser beam R for distance measurement is reflected by the scanning mirrors 18X and 18Y of the galvano scanner 18, and is incident on the fθ lens 19. The incident range-finding laser beam R is focused by the fθ lens 19 and emitted from the fθ lens 19. The emitted distance-finding laser beam R is incident on the machined surface 8 of the machined object 7. The incident laser beam R for distance measurement is reflected by the machined surface 8 of the object to be machined 7, follows the above-mentioned path in the opposite direction, and is received by the TOF sensor 103.

Hereinafter, the position where the distance measuring laser beam R is reflected on the machined surface 8 of the machined object 7 is referred to as a “reflection point”.

In the TOF sensor 103, the time from the emission of the distance measuring laser beam R to the reception of light is measured, and the measured time is converted into the distance. The converted distance is a reciprocating distance between the TOF sensor 103 and the reflection point. Therefore, the distance between the TOF sensor 103 and the reflection point is measured by the TOF sensor 103 by halving the converted distance. Further, when the distance measuring laser beam R is emitted from the TOF sensor 103, if the reflection point is matched with the planned irradiation point by the two-dimensional scanning of the galvano scanner 18, the distance between the TOF sensor 103 and the planned irradiation point is reached. The distance is measured by the TOF sensor 103.

In FIG. 3, the reflection points (planned irradiation points) corresponding to the focal positions F1, F2, and F3 in FIG. 1 are represented by the first measurement point MP1, the second measurement point MP2, and the third measurement point MP3.

Hereinafter, when the positions where the distance is measured by the TOF sensor 103 are generically described without distinguishing between the first measurement point MP1, the second measurement point MP2, and the third measurement point MP3, "measurement point MP" is used. Or, it is expressed as "multiple measurement points MP".

Therefore, in FIG. 3, the distance between the TOF sensor 103 and the planned irradiation point measured by the TOF sensor 103 means the distance between the TOF sensor 103 and the measurement point MP.

Further, in the laser marker 1 of the present embodiment, the distance between the reference position related to the position of the fθ lens 19 and the measurement point MP is calculated from the distance between the TOF sensor 103 and the measurement point MP. In the specific example shown in FIG. 4, the distance from the lower surface of the fθ lens 19 to the measurement point MP (so-called working distance) is defined as the distance between the reference position related to the position of the fθ lens 19 and the measurement point MP. Hereinafter, "distance from fθ lens 19 to measurement point MP") is shown. In addition to the lower surface of the fθ lens 19, the reference position related to the position of the fθ lens 19 includes, for example, the upper surface of the fθ lens 19 or the center of the fθ lens 19 in the vertical direction. Hereinafter, the calculation of the distance from the fθ lens 19 to the measurement point MP will be described with reference to FIG.

As shown in FIG. 4, between the fθ lens 19 and the second measurement point MP2, the passing direction of the distance measuring laser beam R coincides with the vertical direction of the fθ lens 19. Therefore, among the distances between the TOF sensor 103 and the second measurement point MP2 (hereinafter referred to as “second measurement distance V2”) measured by the TOF sensor 103, the fθ lens 19 and the second measurement point MP2 The portion corresponding to between is the same as the distance from the fθ lens 19 to the second measurement point MP2. Therefore, the distance from the fθ lens 19 to the second measurement point MP2 is obtained from the second measurement distance V2 based on the distance from the TOF sensor 103 to the fθ lens 19 and the like. The distance from the TOF sensor 103 to the fθ lens 19 is a known value required by design. Hereinafter, the distance obtained in this way (distance from the fθ lens 19 to the second measurement point MP2) is referred to as a “second calculated distance L2”.

Note that FIG. 4 shows a portion of the second measurement distance V2 corresponding to the distance between the fθ lens 19 and the second measurement point MP2. This point is the same for the first measurement distance V1 and the third measurement distance V3, which will be described later.

On the other hand, between the fθ lens 19 and the first measurement point MP1, the passing direction of the distance measuring laser beam R does not coincide with the vertical direction of the fθ lens 19. Therefore, among the distances between the TOF sensor 103 and the first measurement point MP1 (hereinafter referred to as “first measurement distance V1”) measured by the TOF sensor 103, the fθ lens 19 and the first measurement point MP1 The portion corresponding to between is longer than the (shortest) distance from the fθ lens 19 to the first measurement point MP1. Therefore, the distance from the fθ lens 19 to the first measurement point MP1 is the distance from the TOF sensor 103 to the fθ lens 19 described above, as well as the passing direction of the distance measuring laser beam R and the vertical direction of the fθ lens 19. It is obtained from the first measurement distance V1 based on the intersection angle and the like. Hereinafter, the distance obtained in this way (distance from the fθ lens 19 to the first measurement point MP1) is referred to as “first calculated distance L1”. The angle at which the passing direction of the distance measuring laser beam R and the vertical direction of the fθ lens 19 intersect is obtained from the XY coordinate data of the first measurement point MP1 and the like.

This point is the same between the fθ lens 19 and the third measurement point MP3. That is, the distance from the fθ lens 19 to the third measurement point MP3 is the distance between the TOF sensor 103 and the third measurement point MP3 measured by the TOF sensor 103 (hereinafter referred to as “third measurement distance V3”. ) Is required. Hereinafter, the distance obtained in this way (distance from the fθ lens 19 to the third measurement point MP3) is referred to as a “third calculated distance L3”.

As shown in FIG. 5, each measurement distance V1, V2, V3 and each calculation distance L1, L2, L3 are set to each measurement point MP1, MP2, MP3 (XY coordinate data) in the first data table 210. It is stored in the associated state. The first data table 210 is secured in the RAM 42 of the laser controller 6.

From the above, in the laser marker 1 of the present embodiment, the focal position F of the laser beam P moves to, for example, the first focal position F1, the second focal position F2, and the third focal position F3 in the order of description thereof. In order to make corrections, first, each measurement point MP1, MP2, MP3 is set on the machined surface 8 of the machined object 7. The setting is made based on the print pattern of the image to be marked (printed). As a result, each measurement point MP1, MP2, MP3 is set so as to coincide with the scheduled irradiation point on the machined surface 8 of the machined object 7. After that, for each measurement point MP1, MP2, MP3, each measurement distance V1, V2, V3 is measured by the TOF sensor 103, and each calculation distance L1, L2, L3 is calculated from each measurement distance V1, V2, V3.

Next, when the laser beam P is two-dimensionally scanned on the processing surface 8 of the processing object 7 based on the printing pattern of the image to be marked (printed), the first lens 72 and the second lens 72 in the optical system 70 are scanned. The distance to the lens 74 is the first distance A1, the second, based on the XY coordinate data of the print pattern, the XY coordinate data of each measurement point MP1, MP2, MP3, each calculated distance L1, L2, L3, and the like. The distance A2 and the third distance A3 are adjusted in the order of description. Therefore, the focal position F of the laser beam P moves to the first focal position F1, the second focal position F2, and the third focal position F3 in the order described. As a result, the focal position F of the laser beam P sequentially moves upward and is corrected so as to be on the machined surface 8 of the machined object 7.

Hereinafter, during the marking (printing) processing, the correction that the focal position F of the laser beam P is corrected so as to be on the machined surface 8 of the machining object 7 is referred to as "correction of the focal position F of the laser beam P". do. Further, the distance measured by the TOF sensor 103 (that is, the distance between the TOF sensor 103 and the measurement point MP) is determined without distinguishing between the first measurement distance V1, the second measurement distance V2, and the third measurement distance V3. When described generically, it is expressed as "measurement distance V". Further, the first calculated distance L1, the second calculated distance L2, and the third calculated distance L3 are not distinguished, and the distance from the fθ lens 19 to the measurement point MP (that is, the distance obtained from the measurement distance V) is generically referred to. In the case of the above description, it is expressed as "calculated distance L".

[3. Range of movement of the focal position of the laser beam]
In the laser marker 1 of the present embodiment, the focal position F of the laser beam P is corrected by adjusting the distance from the first lens 72 to the second lens 74 in the optical system 70. The adjustment of the distance from the first lens 72 to the second lens 74 is performed by moving the second lens 74 by the moving mechanism 76. Therefore, there is a moving range of the focal position F of the laser beam P according to the moving range of the second lens 74.

Hereinafter, such a moving range will be referred to as a “correction range of the optical system 70” and will be specifically described.

In the optical system 70, when the distance from the first lens 72 to the second lens 74 is adjusted to be the shortest, the focal position F of the laser beam P moves to the uppermost position. In FIG. 4, the position separated by a distance H1 upward from the second measurement point MP2 is the position where the focal position F of the laser beam P has moved most upward. On the other hand, when the distance from the first lens 72 to the second lens 74 is adjusted to the maximum, the focal position F of the laser beam P moves to the lowermost position. In FIG. 4, the position separated by a distance H2 downward from the second measurement point MP2 is the position where the focal position F of the laser beam P has moved most downward.

Therefore, the correction range H of the optical system 70 is between the position separated by a distance H1 upward from the second measurement point MP2 and the position separated by a distance H2 downward from the second measurement point MP2.

Further, in the laser marker 1 of the present embodiment, if the focal position F of the laser beam P cannot be corrected unless the focal position F of the laser beam P moves beyond the correction range H of the optical system 70, marking is performed. (Printing) No processing or movement of the focal position F of the laser beam P is performed, and a warning to that effect is given on the liquid crystal display 56. In such a case, information for causing the liquid crystal display 56 to give a warning is transmitted from the laser controller 6 to the print information creating unit 2.

[4. Addition of measurement points]
In the laser marker 1 of the present embodiment, when the difference in the calculated distance L between the two adjacent measurement points MP on the machined surface 8 of the machined object 7 exceeds the first reference value SB1 (see FIG. 6 to be described later). , The measurement point MP is added between the two measurement point MPs. Hereinafter, a specific description will be given.

As shown in FIG. 4, the difference between the first calculated distance L1 and the second calculated distance L2 at the first measurement point MP1 and the second measurement point MP2 adjacent to each other on the machining surface 8 of the machining object 7. Is the distance D12. Further, at the second measurement point MP2 and the third measurement point MP3 adjacent to each other on the processing surface 8 of the processing object 7, the difference between the second calculated distance L2 and the third calculated distance L3 is the distance D23.

Here, when the distance D23, which is the difference between the second calculated distance L2 and the third calculated distance L3, exceeds the first reference value SB1, the two measurement points are as shown in FIG. A fourth measurement point MP4 is added while being sandwiched between MP2 and MP3 (for example, near the center between them). For the fourth measurement point MP4, the measurement distance V (distance between the TOF sensor 103 and the fourth measurement point MP4) is measured in the same manner as the measurement points MP1, MP2, and MP3, and the calculated distance L (fθ lens) is measured. The distance from 19 to the 4th measurement point MP4) is obtained.

Further, with respect to the fourth measurement point MP4, the distance D24, which is the difference in the calculated distance L from the second measurement point MP2 adjacent to the machined surface 8 of the machined object 7, and the distance D24 adjacent to the machined object 7 on the machined surface 8. The distance D43, which is the difference in the calculated distance L from the matching third measurement point MP3, is compared with the first reference value SB1 in the same manner as the above-mentioned distance D12 and distance D23.

The first reference value SB1 is stored in the second data table 212 as shown in FIG. The second data table 212 is secured in the ROM 43 of the laser controller 6.

[5. Whether or not the focal position of the laser beam can be moved]
In the laser marker 1 of the present embodiment, if the quality of marking (printing) processing is maintained even if the focal position F of the laser beam P deviates from the processing surface 8 of the object to be machined 7, the laser beam P can be used. The focal position F may not be moved. For example, when the correction distance (moving distance) of the focal position F of the laser beam P is equal to or less than the second reference value SB2 (see FIG. 6), the focal position F of the laser beam P is maintained.

The second reference value SB2 is stored in the second data table 212 as shown in FIG. For the second reference value SB2, for example, a value of the depth of focus of the laser marker 1 or a value of half of the depth of focus is used from the viewpoint of maintaining the quality of the marking (printing) process.

[6. Position of measurement point and incident angle of laser beam]
In the laser marker 1 of the present embodiment, when the measurement point MP is set to coincide with the scheduled irradiation point, the measurement point MP is set as shown in FIG. 8, for example. In FIG. 8, on the machined surface 8 of the object to be machined 7, the image 200 of the print pattern to be marked (printed) is each character of “αβγ”, and the measurement points MP1, MP2, and MP3 are at substantially equal intervals. It is set so as to overlap each character of "αβγ".

Further, in FIG. 8, when the above-mentioned fourth measurement point MP4 is added, the fourth measurement point MP4 is, for example, two measurement points MP2 while being sandwiched between the two measurement points MP2 and MP3. It is set at the position where the straight line connecting MP3s and the character "β" overlap.

When the measurement point MP is set to coincide with the planned irradiation point, the angle at which the distance measuring laser beam R is incident on the scanning mirrors 18X and 18Y of the galvano scanner 18 is the incident angle of the laser beam P. It is the same as the angle.

[7. Laser marker control flow]
The program represented by the flowchart of FIG. 10 is stored in the ROM 43 of the laser controller 6, and is executed by the CPU 41 of the laser controller 6 when the focal position F of the laser beam P is corrected.

In the program represented by the flowchart of FIG. 10, first, in step 10 (hereinafter, simply referred to as “S”) 10, a print pattern acquisition process is performed. In this process, the print pattern of the image 200 to be marked (printed) is stored in the RAM 42 based on the information input from the print information creating unit 2 to the laser controller 6.

Subsequently, the measurement coordinate determination process is performed (S12). In this process, a plurality of measurement point MPs (XY coordinate data) are set based on the print pattern stored in the RAM 42. At that time, the plurality of measurement point MPs (XY coordinate data) are set so as to overlap with the image 200 of the print pattern, for example, as shown in FIG.

When a plurality of measurement points MP (XY coordinate data) are set, the measurement process is performed (S14). In this process, the distance measuring laser beam R emitted from the TOF sensor 103 is generated by rotating the scanning mirrors 18X and 18Y of the galvano scanner 18 based on the measurement point MP (XY coordinate data). It is reflected by the MP and is incident on the TOF sensor 103. As a result, the measurement distance V is measured at each measurement point MP.

When the measurement distance V is measured at each measurement point MP, the measurement distance is stored (S16). In this process, for example, as shown in FIG. 5, the measurement distance V for each measurement point MP is stored in the first data table 210 in a state of being associated with the measurement point MP (XY coordinate data). Will be done.

When the measurement distance V is stored for each measurement point MP, the calculation process is performed (S18). In this process, the calculated distance L is calculated for each measurement distance V. This calculation is performed based on the measurement distance V as described above.

When the calculated distance L is calculated for each measurement point MP, the calculated distance is stored (S20). In this process, for example, as shown in FIG. 5, the calculated distance L for each measurement point MP is stored in the first data table 210 in a state of being associated with the measurement point MP (XY coordinate data). Will be done.

When the calculated distance L is stored for each measurement point MP, it is determined whether or not the correction of the focal position F of the laser beam P is performed outside the correction range H of the optical system 70 (S22). That is, whether or not the destination of the focal position F of the laser beam P is outside the correction range H of the optical system 70 is determined for each measurement point MP. This determination is made based on the measurement point MP (XY coordinate data), the calculated distance L, and the like.

Here, if at least one of the destinations of the focal position F of the laser beam P is outside the correction range H of the optical system 70 (S22: YES), a warning process is performed (S24). In this process, as described above, a warning that the focal position F of the laser beam P cannot be corrected is displayed on the liquid crystal display 56. It should be noted that such a warning may be given by outputting a warning sound from a speaker (not shown). After that, the program represented by the flowchart of FIG. 10 ends.

On the other hand, when all the destinations of the focal position F of the laser beam P are within the correction range H of the optical system 70 (S22: NO), 2 adjacent to each other on the machined surface 8 of the machined object 7. It is determined whether or not all the differences in the calculated distances L at the two measurement points MP are equal to or less than the first reference value SB1 (S26). This determination is made based on the measurement point MP (XY coordinate data), the calculated distance L, and the like.

Here, when all the differences in the calculated distances L at the two adjacent measurement points MP on the machined surface 8 of the machined object 7 are equal to or less than the first reference value SB1 (S26: YES), the command value The determination process is performed (S28). In this process, control parameters related to the distance from the first lens 72 to the second lens 74 in the optical system 70, which are command values for the optical system driver 78, are determined for each measurement point MP. This determination is made based on the measurement point MP (XY coordinate data), the calculated distance L, and the like.

However, the difference in the distances from the first lens 72 to the second lens 74 in the optical system 70 between the two adjacent measurement points MP on the machined surface 8 of the machined object 7 is small, and therefore, as described above. As described above, when the correction distance (moving distance) of the focal position F of the laser beam P is equal to or less than the second reference value SB2, the distance from the first lens 72 to the second lens 74 in the optical system 70 is maintained. The command value of is determined.

Subsequently, a printing process is performed (S30). In this process, the distance from the first lens 72 to the second lens 74 in the optical system 70 is adjusted for each measurement point MP by moving the second lens 74 of the optical system 70 based on the command value of S28. Then, the laser beam P is two-dimensionally scanned by the galvano scanner 18 based on the print pattern, so that the image 200 is marked (printed) on the machined surface 8 of the machined object 7.

As a result, the focal position F of the laser beam P is corrected. After that, the program represented by the flowchart of FIG. 10 ends.

On the other hand, when at least one of the differences in the calculated distances L at the two adjacent measurement points MP on the machined surface 8 of the machined object 7 is larger than the first reference value SB1 (S26: NO), Additional processing of measurement coordinates is performed (S32). In this process, a new measurement point MP (XY coordinate data) is set between the two measurement point MPs in which the difference in the calculated distance L is larger than the first reference value SB1. At that time, the new measurement point MP (XY coordinate data) is set in the same manner as the already set measurement point MP (XY coordinate data) so as to overlap with the image 200 of the print pattern.

After that, the above-mentioned processing after S14 is repeated.

[8. summary]
As described in detail above, in the laser marker 1 of the present embodiment, the measurement distance V measured based on the print pattern of the image 200 to be marked (printed) is used (S14, S16), and the laser light is used. By correcting the focal position F of P (S18 to S22, S26 to S30), the printing accuracy by the laser beam P is improved.

Further, in the laser marker 1 of the present embodiment, the laser beam P and the distance measuring laser beam R are incident on the scanning mirrors 18X and 18Y of the galvano scanner 18 at the same angle. Therefore, in the command value determination process (S28), it is possible to use a plurality of measurement point MPs (XY coordinate data) determined in the measurement coordinate determination process (S12), so that the command value determination process (S28) can be used. ) And the data in the printing process (S30) are easy to handle.

Further, in the laser marker 1 of the present embodiment, the optical axis of the range-finding laser beam R coincides with the optical axis 10 of the laser beam P. Therefore, the laser marker 1 of the present embodiment can make the scanning mirrors 18X and 18Y of the galvano scanner 18 smaller.

Further, in the laser marker 1 of the present embodiment, a plurality of measurement point MPs are set so as to overlap the image 200 of the print pattern to be marked (printed) (S10, S12). Therefore, the laser marker 1 of the present embodiment is excellent in the accuracy and efficiency of correction of the focal position F of the laser beam P.

Further, in the laser marker 1 of the present embodiment, when the difference in the calculated distance L between the two adjacent measurement points MP on the machined surface 8 of the machined object 7 exceeds the first reference value SB1, (S26: NO). , A new measurement point MP is added between the two adjacent measurement point MPs (S32). Therefore, the accuracy of correction of the focal position F of the laser beam P is improved.

Further, in the laser marker 1 of the present embodiment, it takes a certain amount of time to move the second lens 74 of the optical system 70. In this regard, in the command value determination process (S28), the second lens 74 of the optical system 70 is moved only when the correction distance (movement distance) of the focal position F of the laser beam P exceeds the second reference value SB2. The command value to be made is determined. Therefore, the time required for marking (printing) processing is shortened.

Further, in the laser marker 1 of the present embodiment, for example, the value of the depth of focus of the laser marker 1 or the value of half of the depth of focus is used as the second reference value SB2, so that the quality of marking (printing) processing is used. Is retained.

Further, in the laser marker 1 of the present embodiment, the measurement distance V is measured by the TOF sensor 103. Therefore, the laser marker 1 of the present embodiment is excellent in the accuracy of the measurement distance V.

Further, in the laser marker 1 of the present embodiment, the calculated distance L obtained from the measurement distance V is used (S18, S20) to correct the focal position F of the laser beam P (S22, S26 to). S30), the printing accuracy by the laser beam P is further improved.

Further, in the laser marker 1 of the present embodiment, when at least one of the destinations of the focal position F of the laser beam P is outside the correction range H of the optical system 70 (S22: YES), the focal position of the laser beam P A warning to the effect that the correction of F cannot be performed is given on the liquid crystal display 56 (S24). Therefore, failure of marking (printing) processing is suppressed.

Incidentally, in the present embodiment, the planned irradiation point is an example of the “irradiation position”. The processing object 7 is an example of a “distance measuring object”. The laser oscillation unit 12 is an example of a “laser light source”. The galvano scanner 18 is an example of a “scanning unit”. The scanning mirrors 18X and 18Y are examples of "mirrors". The CPU 41 of the laser controller 6 is an example of a “control unit”. The RAM 42 of the laser controller 6 is an example of a “storage unit”. The liquid crystal display 56 is an example of a “warning unit”. The optical system 70 is an example of a “variable focus optical system”. The TOF sensor 103 is an example of a “distance measuring unit” and a “TOF type sensor”. The image 200 to be marked (printed) is an example of an "object". The laser beam P is an example of "laser beam for processing".

The measurement distance V (distance between the TOF sensor 103 and the measurement point MP) is an example of "distance between the distance measurement object" and "distance between the measurement point and the distance measurement unit". The calculated distance L is an example of “the distance between the reference position and the measurement point related to the position of the fθ lens”. The correction range H of the optical system 70 is an example of the “correction range of the variable focus optical system”.

[9. others]
The present disclosure is not limited to the present embodiment, and various changes can be made without departing from the spirit of the present embodiment.

For example, instead of the measurement coordinate addition process (S32), the measurement coordinate determination process (S12) may be performed again with the total number of measurement point MPs increased.

Further, the measurement point MP may be set so as not to coincide with the planned irradiation point. In such a case, for example, the measurement point MP is set as shown in FIG. In FIG. 9, on the machined surface 8 of the object to be machined 7, the image 200 of the print pattern to be marked (printed) is each character of “αβγ” and overlaps with the rectangle 202 inscribed by each character of “αβγ”. In this way, each measurement point MP1, MP2, MP3 is set.

The first measurement point MP1 and the third measurement point MP3 are set at both ends of the upper side of the rectangle 202. The second measurement point MP2 is set at the center of the upper side of the rectangle 202. The rectangle 202 indicates the range of the image 200 of the print pattern to be marked (printed), and is the same as the one projected by the visible laser light Q on the processed surface 8 of the object to be processed 7.

Further, in FIG. 9, when the above-mentioned fourth measurement point MP4 is added, the fourth measurement point MP4 is, for example, among the upper sides of the rectangle 202 while being sandwiched between the two measurement points MP2 and MP3. It is set at the center position between the two measurement points MP2 and MP3.

Further, the measurement points MP may be set in a grid pattern within the rectangle 202. Further, the interval of the measurement points MP set in a grid pattern in the rectangle 202 may be determined according to the interval between the four corners of the rectangle 202 or the difference in the measurement distance V at the four corners of the rectangle 202.

When the measurement point MP is set so as not to coincide with the planned irradiation point, the distance measuring laser beam R and the laser beam P are incident on the scanning mirrors 18X and 18Y of the galvano scanner 18 at different angles. Will be done.

In this way, when the measurement point MP is set so as not to coincide with the scheduled irradiation point, the total number of measurement point MPs is suppressed, so that the time required for correcting the focal position F of the laser beam P is shortened.

Further, for a plurality of measurement point MPs, some measurement point MPs may be set so as to coincide with the scheduled irradiation points, and the remaining measurement point MPs may be set so as not to coincide with the scheduled irradiation points. The setting mode of the measurement point MP (XY coordinate data) may be determined in advance, or may be determined by the operation of the input operation unit 55 by the user.

Further, instead of the TOF sensor 103, a phase difference detection type sensor may be used, or a triangular distance measuring type sensor may be used.

Further, the correction of the focal position F of the laser beam P may be performed without obtaining the calculated distance L. In such a case, the measurement distance V is used instead of the calculated distance L.

Further, the galvano scanner 18 and the fθ lens 19 may not be used. In such a case, for example, a reflection mirror having no scanning function or a condenser lens may be used, and an XY stage on which the object to be processed 7 is mounted may be used as the scanning unit. Further, a condenser lens or an XY stage may be arranged so that the reflection mirror is omitted.

1: Laser marker, 7: Machined object, 8: Machined surface of the machined object, 10: Optical axis, 12: Laser oscillation unit, 18: Galvano scanner, 18X: Scanning mirror, 18Y: Scanning mirror, 19: fθ lens, 41: CPU, 42: RAM, 56: LCD display, 70: Optical system, 103: TOF sensor, 200: Image, 202: Rectangular, F: Focus position, H: Optical system correction range, L: Calculated distance, MP : Measurement point, P: Laser light, R: Laser light for distance measurement, SB1: First reference value, SB2: Second reference value, V: Measurement distance

Claims (11)

A laser light source that emits a laser beam for processing to print an object on the machined surface of the object to be machined,
A distance measuring unit that measures the distance to the distance measuring object by emitting the distance measuring laser light and receiving the distance measuring laser light reflected by the distance measuring object.
A scanning unit that irradiates and scans the processing laser beam and the distance measuring laser beam toward the processing surface of the processing object.
A variable focus optical system that moves and corrects the focal position of the processing laser beam, and
A storage unit in which the print pattern of the object is stored, and a storage unit.
Equipped with a control unit
The control unit
A plurality of measurement points are set on the machined surface of the object to be machined based on the print pattern of the object.
The distance between the measurement point and the distance measurement unit acquired by reflecting the distance measurement laser beam at the plurality of measurement points is used as the measurement distance in the storage unit in association with the measurement point. Remember,
When scanning the processing laser beam on the processing surface of the object to be processed based on the print pattern of the object, the processing laser is based on the print pattern of the object, the measurement point, and the measurement distance. Correct the focal position of the light ,
The plurality of measurement points are located at irradiation positions where the processing laser beam is applied onto the processing surface of the processing object based on the print pattern of the object.
When the difference between the measurement distances at the two measurement points adjacent to each other on the machining surface of the object to be machined exceeds the first reference value among the plurality of measurement points, the control unit may use the adjacent 2 measurement points. A laser marker characterized in that the measurement point is added at a position where the straight line connecting the two adjacent measurement points and the irradiation position overlap in the vicinity of the center between the measurement points . The scanning unit is a mirror.
The laser marker according to claim 1, wherein at least a part of the processing laser light and the distance measuring laser light is incident on the mirror at the same angle. The laser marker according to claim 2, wherein the optical axes of the processing laser beam and the ranging laser beam incident on the mirror at the same angle are coaxial. Claims 1 to 3 are characterized in that the control unit corrects the focal position of the processing laser beam only when the correction distance of the focal position of the processing laser beam exceeds the second reference value. The laser marker according to any one of the above. The laser marker according to claim 4 , wherein the second reference value is equal to or less than the depth of focus of the laser marker. The laser marker according to claim 4 , wherein the second reference value is not more than half the depth of focus of the laser marker. The laser marker according to any one of claims 1 to 6 , wherein the ranging unit is a TOF type sensor. It is provided with an fθ lens that condenses the processing laser beam and the distance measuring laser light incident through the scanning unit on the processing object.
The control unit measures the measurement of all of the plurality of measurement points by using the distance between the measurement point and the reference position related to the position of the fθ lens calculated based on the measurement distance as the measurement distance. The laser marker according to any one of claims 1 to 6 , wherein the laser marker is stored in the storage unit in association with a point. Equipped with a warning section that warns the user
Claims 1 to 8 are characterized in that the control unit activates the warning unit when the destination of the focal position of the processing laser beam is outside the correction range of the variable focus optical system. The laser marker according to any one of the above. A laser light source that emits a laser beam for processing to print an object on the machined surface of the object to be machined,
A distance measuring unit that measures the distance to the distance measuring object by emitting the distance measuring laser light and receiving the distance measuring laser light reflected by the distance measuring object.
A scanning unit that irradiates and scans the processing laser beam and the distance measuring laser beam toward the processing surface of the processing object.
A variable focus optical system that moves and corrects the focal position of the processing laser beam, and
A storage unit in which the print pattern of the object is stored, and a storage unit.
Equipped with a control unit
The control unit
A plurality of measurement points are set on the machined surface of the object to be machined based on the print pattern of the object.
The distance between the measurement point and the distance measurement unit acquired by reflecting the distance measurement laser beam at the plurality of measurement points is used as the measurement distance in the storage unit in association with the measurement point. Remember,
When scanning the processing laser beam on the processing surface of the object to be processed based on the print pattern of the object, the processing laser is based on the print pattern of the object, the measurement point, and the measurement distance. Correct the focal position of the light,
The plurality of measurement points are located at positions where the image of the print pattern of the object overlaps the inscribed rectangle or the grid in the rectangle.
When the difference between the measurement distances at the two measurement points adjacent to each other on the machining surface of the object to be machined exceeds the first reference value among the plurality of measurement points, the control unit may use the adjacent 2 measurement points. A laser marker comprising adding the measurement point at a position at the center of two adjacent measurement points while being sandwiched between the measurement points. The plurality of measurement points are characterized by being on a rectangle surrounding the object printed on the machined surface of the object to be machined by irradiating the laser beam for processing based on the print pattern of the object. The laser marker according to claim 10 .

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