JP7405605B2 - laser processing equipment - Google Patents

Description

The technology disclosed herein relates to a laser processing device, such as a laser marking device, that performs processing by irradiating a workpiece with laser light.

2. Description of the Related Art Conventionally, laser processing devices that can measure the distance to a workpiece are known.

For example, Patent Document 1 describes an objective focusing lens that focuses laser light (pulsed laser light) emitted from a laser light source, and a distance between the objective focusing lens and a workpiece (workpiece). A laser processing device is disclosed that includes a distance measurement sensor that measures distance and an actuator that adjusts the focal position of laser light based on the measurement result of the distance measurement sensor.

The distance measurement sensor according to Patent Document 1 is supported by a Z-axis stage, as illustrated in the document. Therefore, this distance measuring sensor has a non-variable distance measuring position and measures the distance to a fixed point.

In addition, it is widely known that laser processing equipment projects a processing pattern onto the surface of a workpiece by emitting a guide light onto the surface of the workpiece in order to let the user visually confirm the processing contents in advance. There is.

For example, the laser processing apparatus disclosed in Patent Document 2 is configured to include a guide light emitting section (guide light source) capable of emitting guide light. This guide light emitting section is coaxial with the optical axis of the laser beam scanning system, and the guide light can be scanned by the laser beam scanning system.

Japanese Patent Application Publication No. 2006-315031 Japanese Patent Application Publication No. 2008-227377

In the configuration in which the ranging position is not variable as in Patent Document 1, there remains room for improvement in the usability of the ranging sensor. Therefore, by making the optical axis of the distance measuring light emitted from the distance measuring sensor and the optical axis of the laser beam for processing (especially the optical axis of the laser beam scanning system) coaxial, the laser beam scanning system It is conceivable to scan the distance measuring light by using the following method.

However, in a device equipped with a coaxial guide light emitting section, such as the laser processing device disclosed in Patent Document 2, if the distance measurement sensor is also made coaxial, the distance measurement sensor may be disposed on the surface of the workpiece. At least a portion of the reflected distance measurement light may return to the guide light emitting section instead of the distance measurement sensor, resulting in a decrease in the amount of light received by the distance measurement sensor. A decrease in the amount of light received by the distance measurement sensor is inconvenient because it leads to a decrease in measurement accuracy.

The technology disclosed herein has been developed in view of this point, and its purpose is to ensure distance measurement accuracy while coaxially guiding the guide light and distance measurement light with the processing laser light. It is in.

Specifically, a first aspect of the present disclosure includes an excitation light generation unit that generates excitation light, and a laser beam that is generated based on the excitation light generated by the excitation light generation unit and that emits the laser beam. a laser beam output section that irradiates a workpiece with a laser beam emitted from the laser beam output section and scans the surface of the workpiece two-dimensionally; and a casing in which the laser beam scanning section is provided. This laser processing apparatus includes a guide light emitting section that is provided inside the housing and emits a guide light for projecting a predetermined processing pattern onto the surface of the workpiece; a guide light merging mechanism provided in the middle of the laser light path from the laser light output section to the laser light scanning section and for merging the guide light emitted from the guide light emitting section into the laser light path; a distance measuring light emitting unit that emits a distance measuring light for measuring the distance from the laser processing device to the surface of the workpiece; and a convergence of the guide light in the laser optical path inside the housing. a distance measuring light merging mechanism provided between the mechanism and the laser beam scanning section and configured to merge the distance measuring light emitted from the distance measuring light emitting section into the laser optical path; and a distance measuring light merging mechanism provided inside the casing; a distance measurement light receiving section that receives distance measurement light reflected on the surface of the workpiece and returned via the laser beam scanning section and the distance measurement light merging mechanism; and distance measurement in the distance measurement light receiving section. The apparatus further includes a distance measuring section that measures the distance from the laser processing device to the surface of the workpiece based on the light receiving position.

According to the first aspect of the present disclosure, the ranging light merging mechanism includes an optical member that guides the ranging light reflected on the surface of the workpiece to the ranging light receiving section, The optical member selectively reflects or transmits only the wavelength band of the distance measurement light among the respective wavelength bands of the laser beam, the guide light, and the distance measurement light, so that the distance measurement light is transmitted through the distance measurement light. Guide to the distance light receiver.

According to this configuration, when measuring the distance from the laser processing device to the surface of the workpiece, the distance measurement light emitting section emits distance measurement light. The ranging light emitted from the ranging light emitting section passes through the ranging light merging mechanism and the laser beam scanning section in order, and is irradiated onto the workpiece. The distance measurement light irradiated onto the workpiece is reflected by the workpiece, and then returns through the laser beam scanning section and the distance measurement light merging mechanism in order to reach the distance measurement light receiving section. The distance measuring section measures the distance to the surface of the workpiece based on the distance measuring light receiving position in the distance measuring light receiving section.

Moreover, when irradiating the guide light onto the surface of the workpiece, the guide light emitting section emits the guide light. The guide light emitted from the guide light emitting section passes through the guide light merging mechanism, the ranging light merging mechanism, and the laser beam scanning section in this order, and is irradiated onto the workpiece.

According to the above configuration, the guide light emitting section and the distance measuring light emitting section are each coaxial with the laser beam for processing, so that the guide light and the distance measuring light can be scanned by the laser beam scanning section. become.

Specifically, the guide light merging mechanism is disposed in the middle of the laser beam path from the laser beam output section to the laser beam scanning section, and the ranging light merging mechanism is arranged between the guide light merging mechanism and the laser beam scanning section in the laser beam path. placed in between. In this arrangement, the distance measuring light reflected on the surface of the workpiece and returned to the laser processing device reaches the distance measuring light combining mechanism before reaching the guide light combining mechanism.

Here, the optical member constituting the ranging light merging mechanism selectively reflects or transmits only the wavelength band of the ranging light among the respective wavelength bands of the processing laser light, the guide light, and the ranging light. Accordingly, the distance measuring light is guided to the distance measuring light receiving section. With this configuration, it is possible to suppress the propagation of the distance measurement light (in particular, the reflected light of the distance measurement light) to the guide light emitting section, and increase the amount of light received by the distance measurement light receiving section. This makes it possible to suppress a decrease in measurement accuracy.

According to the second aspect of the present disclosure, the optical member may be coated so as to selectively reflect or transmit only the wavelength band of the ranging light.

According to this configuration, an optical member suitable for selective reflection or transmission can be configured.

Further, according to the third aspect of the present disclosure, the optical member selectively reflects only the wavelength band of the ranging light, while transmitting the respective wavelength bands of the laser beam and the guide light. Good too.

This configuration is advantageous in suppressing a decrease in measurement accuracy.

According to the fourth aspect of the present disclosure, the front and back surfaces of the optical member include a laser light entrance surface on which the laser light and the guide light enter, and a laser light entrance surface on which the laser light and the guide light enter, and a laser light entrance surface on which the laser light and the guide light enter. a laser beam exit surface through which the guide light passes through the optical member and is emitted; the laser beam exit surface selectively reflects only the wavelength band of the distance measuring light; may be configured to transmit the wavelength band of the distance measuring light.

According to this configuration, the laser light emitting surface of the optical member can reflect the distance measurement light and guide the distance measurement light to the laser beam scanning section or the distance measurement light receiving section. However, it is technically not easy to set the reflectance of the laser beam exit surface to exactly 100%. Therefore, a part of the distance measuring light incident on the laser beam output surface passes through the laser beam output surface without being reflected by the laser beam output surface. The distance measuring light that has passed through the laser beam exit surface passes through the interior of the optical member while being refracted, and reaches the laser beam entrance surface.

If the distance measuring light that reaches the laser beam incident surface is reflected by the laser beam incident surface and returns to the distance measuring light receiving section, the distance measuring light receiving section will be exposed to the laser beam emitting surface and the laser beam. The distance measuring light reflected by the incident surface will both return. In this case, there is a possibility that the light receiving position in the distance measuring light receiving section becomes blurred. This is undesirable because it leads to a decrease in measurement accuracy. These problems become more noticeable when the reflectance at the laser beam exit surface is low.

Therefore, as in the above configuration, the laser light incident surface transmits the wavelength band of the ranging light without reflecting it. As a result, the distance measurement light that has passed through the laser beam exit surface and reached the laser beam entrance surface is suppressed from being reflected on the laser beam entrance surface, and is emitted from the laser beam entrance surface to the outside. Become. Thereby, it is possible to suppress blurring of the light receiving position in the distance measuring light receiving section and to suppress a decrease in measurement accuracy.

According to the fifth aspect of the present disclosure, the optical member selectively transmits only the wavelength band of the ranging light, while selectively reflecting the wavelength bands of the laser beam and the guide light. It may be said to do.

This configuration is advantageous in suppressing a decrease in measurement accuracy.

Further, according to the sixth aspect of the present disclosure, the laser processing device includes a focus adjustment section that is provided inside the housing and adjusts a focal position of the laser light emitted from the laser light output section. The distance measuring light merging mechanism may be arranged in the laser optical path between the focus adjustment section and the laser beam scanning section.

According to this configuration, the distance measuring light merging mechanism is disposed between the focus adjustment section and the laser beam scanning section, and combines the distance measurement light emitted from the distance measurement light emitting section with the laser beam that has passed through the focus adjustment section. and make them coaxial. Therefore, since the distance measuring light is made coaxial in the optical path upstream of the laser beam scanning section, the distance measuring light can be scanned by operating the laser beam scanning section.

At the same time, the distance measuring light is also made coaxial in the optical path downstream of the focus adjustment section. Therefore, measurement resolution by the distance measuring light can be ensured without making the aperture of the focus adjustment section excessively large.

Further, according to the above configuration, not only the ranging light emitted from the ranging light emitting section but also the ranging light reflected by the workpiece and received by the ranging light receiving section passes through the focus adjustment section. do not. Therefore, the ranging light emitting section and the ranging light receiving section can be disposed close to each other, and it is possible to suppress effects such as distortion of the casing due to temperature changes. This is effective in ensuring measurement accuracy by the distance measuring section.

According to the seventh aspect of the present disclosure, the guide light merging mechanism is arranged between the laser light output section and the focus adjustment section in the laser light path.

According to this configuration, the guide light emitted from the guide light emitting section passes through the guide light merging mechanism, the focus adjustment section, the distance measuring light merging mechanism, and the laser beam scanning section in order to process the workpiece. Objects are irradiated.

Here, the guide light combining mechanism is provided between the laser light output section and the focus adjustment section, and the guide light emitted from the guide light output section and the laser light emitted from the laser light output section, Make it coaxial. Therefore, since the guide light and the laser light join in the optical path upstream of the focus adjustment section, the focal position of the guide light can be adjusted by operating the focus adjustment section. This makes it possible to improve the visibility of the guide light.

According to the eighth aspect of the present disclosure, the wavelength bands of the ranging light and the guide light are both set in the visible light range, and the wavelength of the laser light is set to the wavelength range of the ranging light and the guide light. It may be longer than the wavelength of

According to this configuration, the distance measuring light and the guide light can be visually recognized by the user.

According to the ninth aspect of the present disclosure, the wavelength of the laser beam is set to 1064 nm, 532 nm, or 355 nm, the wavelength band of the ranging light is set to 680 nm or more and 695 nm or less, and The wavelength band may be set to 645 nm or more and 660 nm or less.

According to this configuration, only the wavelength band of the ranging light can be selectively reflected or transmitted.

As explained above, according to the laser processing apparatus, distance measurement accuracy can be ensured while making the guide light and the distance measurement light coaxial with the processing laser light.

FIG. 1 is a diagram illustrating the overall configuration of a laser processing system. FIG. 2 is a block diagram illustrating a schematic configuration of a laser processing device. FIG. 3A is a block diagram illustrating a schematic configuration of a marker head. FIG. 3B is a block diagram illustrating a schematic configuration of the marker head. FIG. 4 is a perspective view illustrating the appearance of the marker head. FIG. 5 is a diagram illustrating the configuration of the laser beam scanning section. FIG. 6 is a diagram illustrating the configuration of a laser beam guide section, a laser beam scanning section, and a distance measuring unit. FIG. 7 is a cross-sectional view illustrating an optical path connecting the laser beam guide section, the laser beam scanning section, and the distance measuring unit. FIG. 8 is a perspective view illustrating an optical path connecting the laser beam guide section, the laser beam scanning section, and the distance measuring unit. FIG. 9 is a diagram illustrating the triangulation method. FIG. 10 is a flowchart illustrating a workpiece machining procedure. FIG. 11 is a perspective view illustrating the configuration of the downstream merging mechanism viewed from the rear. FIG. 12 is a perspective view illustrating the configuration of the downstream merging mechanism viewed from the front. FIG. 13A is a diagram illustrating the reflectance of the laser beam entrance surface according to the first embodiment. FIG. 13B is a diagram illustrating the reflectance of the laser beam emitting surface according to the first embodiment. FIG. 14A is a diagram illustrating optical paths of near-infrared laser light and guide light in the downstream merging mechanism. FIG. 14B is a diagram illustrating the optical path of distance measuring light in the downstream merging mechanism. FIG. 15A is a diagram corresponding to FIG. 3A illustrating a marker head according to a second embodiment of the laser processing apparatus. FIG. 15B is a diagram corresponding to FIG. 3B illustrating the marker head according to the second embodiment of the laser processing apparatus. FIG. 16A is a diagram corresponding to FIG. 13A illustrating the reflectance of the laser beam entrance surface according to the second embodiment. FIG. 16B is a diagram corresponding to FIG. 13B illustrating the reflectance of the laser beam exit surface according to the second embodiment. FIG. 17A is a diagram corresponding to FIG. 14A illustrating optical paths of near-infrared laser light and guide light in the second embodiment. FIG. 17B is a diagram corresponding to FIG. 14B illustrating the optical path of the ranging light in the second embodiment. FIG. 18 is a diagram illustrating combinations of wavelengths that can be taken by the near-infrared laser beam, the guide light, and the ranging light.

Embodiments of the present disclosure will be described below based on the drawings. Note that the following explanation is an example.

That is, although this specification describes a laser marker as an example of a laser processing device, the technology disclosed herein can be applied to laser application equipment in general, regardless of the name of the laser processing device or laser marker.

Further, in this specification, printing processing will be described as a representative example of processing, but the present invention is not limited to printing processing, and can be used in any processing using laser light, such as image marking.

《First embodiment》
First, a laser processing system S including a first embodiment of a laser processing apparatus L will be described. In the following description, the first embodiment will simply be referred to as the present embodiment, unless it is emphasized that the configuration is unique to the first embodiment.

<Overall configuration>
FIG. 1 is a diagram illustrating the overall configuration of a laser processing system S, and FIG. 2 is a diagram illustrating a schematic configuration of a laser processing device L in the laser processing system S. The laser processing system S illustrated in FIG. 1 includes a laser processing device L, an operation terminal 800 and an external device 900 connected to the laser processing device L.

The laser processing apparatus L illustrated in FIGS. 1 and 2 irradiates a workpiece W as a workpiece with laser light emitted from the marker head 1, and performs three-dimensional scanning on the surface of the workpiece W. Processing is done by doing this. Note that "three-dimensional scanning" here refers to a two-dimensional operation of scanning the irradiation position of the laser beam on the surface of the work W (so-called "two-dimensional scanning") and adjusting the focal position of the laser beam. It refers to a concept that collectively refers to the combination of one-dimensional movement and.

In particular, the laser processing apparatus L according to this embodiment can emit a laser beam having a wavelength of around 1064 nm as a laser beam for processing the workpiece W. This wavelength corresponds to the near-infrared (NIR) wavelength range. Therefore, in the following description, the laser beam for processing the workpiece W may be referred to as "near-infrared laser beam" to distinguish it from other laser beams. Of course, laser beams having other wavelengths may be used to process the workpiece W.

Specifically, the wavelength of the laser beam used to process the workpiece W can be set to, for example, 532 nm or 355 nm as an option other than 1064 nm. The wavelength of 532 nm corresponds to the green visible light range, and the wavelength of 355 nm corresponds to the near-ultraviolet (NUV) wavelength range.

Further, the laser processing apparatus L according to the present embodiment measures the distance (height) to the workpiece W via the distance measuring unit 5 built into the marker head 1, and uses the measurement result to The focal position of the external laser beam can be adjusted.

As shown in FIGS. 1 and 2, the laser processing apparatus L includes a marker head 1 for emitting laser light and a marker controller 100 for controlling the marker head 1.

The marker head 1 and the marker controller 100 are separate bodies in this embodiment, and are electrically connected via electrical wiring and optically coupled via an optical fiber cable.

More generally, one of the marker head 1 and the marker controller 100 can be integrated into the other. In this case, optical fiber cables and the like can be omitted as appropriate.

The operation terminal 800 includes, for example, a central processing unit (CPU) and a memory, and is connected to the marker controller 100. This operation terminal 800 functions as a terminal for setting various processing conditions such as print settings and for showing information related to laser processing to the user. This operation terminal 800 includes a display section 801 for displaying information to the user, an operation section 802 for receiving operation input from the user, and a storage device 803 for storing various information.

Specifically, the display section 801 is configured by, for example, a liquid crystal display or an organic EL panel. The display unit 801 displays the operating status and processing conditions of the laser processing apparatus L as information related to laser processing. On the other hand, the operation unit 802 includes, for example, a keyboard and/or a pointing device. Here, the pointing device includes a mouse, a joystick, and the like. The operation unit 802 is configured to accept operation input from a user, and is used to operate the marker head 1 via the marker controller 100.

The operation terminal 800 configured as described above can set processing conditions for laser processing based on the operation input by the user. These processing conditions include, for example, the character string to be printed on the workpiece W, the contents of figures such as barcodes and QR codes (registered trademark) (marking patterns), the output required for the laser beam (target output), and , the scanning speed of the laser beam on the workpiece W (scanning speed).

Further, the processing conditions according to the present embodiment also include conditions and parameters related to the above-mentioned distance measuring unit 5 (hereinafter also referred to as "distance measuring conditions"). Such distance measurement conditions include, for example, data that associates the signal indicating the detection result by the distance measurement unit 5 with the distance to the surface of the workpiece W.

The processing conditions set by the operation terminal 800 are output to the marker controller 100 and stored in its condition setting storage unit 102. If necessary, the storage device 803 in the operation terminal 800 may store the processing conditions.

Note that the operation terminal 800 can be integrated into, for example, the marker controller 100. In this case, the term "control unit" or the like is used instead of "operation terminal," but at least in this embodiment, the operation terminal 800 and the marker controller 100 are separate from each other.

The external device 900 is connected to the marker controller 100 of the laser processing apparatus L as necessary. In the example shown in FIG. 1, an image recognition device 901 and a programmable logic controller (PLC) 902 are provided as the external device 900.

Specifically, the image recognition device 901 determines, for example, the type and position of the work W being transported on the manufacturing line. As the image recognition device 901, for example, an image sensor can be used. PLC902 is used to control the laser processing system S according to a predetermined sequence.

In addition to the devices and apparatuses described above, the laser processing apparatus L can also be connected to devices for operation and control, computers for performing various other processes, storage devices, peripheral devices, and the like. The connection in this case may be, for example, a serial connection such as IEEE1394, RS-232, RS-422, and USB, or a parallel connection. Alternatively, electrical, magnetic, or optical connections can be employed via networks such as 10BASE-T, 100BASE-TX, 1000BASE-T, etc. In addition to the wired connection, a wireless LAN such as IEEE802, or a wireless connection using radio waves such as Bluetooth (registered trademark), infrared rays, optical communication, etc. may be used. Further, as the storage medium used in the storage device for exchanging data and storing various settings, for example, various memory cards, magnetic disks, magneto-optical disks, semiconductor memories, hard disks, etc. can be used.

Hereinafter, the hardware configuration of each of the marker controller 100 and the marker head 1, and the configuration related to the control of the marker head 1 by the marker controller 100 will be described in order.

<Marker controller 100>
As shown in FIG. 2, the marker controller 100 includes a condition setting storage section 102 that stores the processing conditions described above, a control section 101 that controls the marker head 1 based on the processing conditions stored therein, and a laser excitation control section 102 that controls the marker head 1 based on the processing conditions stored therein. It includes an excitation light generation section 110 that generates light (excitation light).

(Condition setting storage unit 102)
The condition setting storage unit 102 is configured to store machining conditions set via the operation terminal 800 and output the stored machining conditions to the control unit 101 as necessary.

Specifically, the condition setting storage unit 102 is configured using a volatile memory, a non-volatile memory, a hard disk drive (HDD), a solid state drive (SSD), etc., and stores processing conditions. Information indicating the information can be stored temporarily or continuously. Note that when the operating terminal 800 is incorporated into the marker controller 100, the storage device 803 can be configured to also serve as the condition setting storage section 102.

(Control unit 101)
The control unit 101 controls at least the excitation light generation unit 110 in the marker controller 100, the laser light output unit 2, the laser light guide unit 3, and the laser light guide unit 3 in the marker head 1, based on the processing conditions stored in the condition setting storage unit 102. By controlling the laser beam scanning section 4, the distance measuring unit 5, and the wide-area camera (non-coaxial camera) 6, which will be described later, printing processing on the workpiece W, etc. is executed.

Specifically, the control unit 101 has a CPU, a memory, and an input/output bus, and receives signals indicating information input via the operating terminal 800 and processing conditions read from the condition setting storage unit 102. A control signal is generated based on the signal shown. The control unit 101 controls printing processing on the workpiece W and measurement of the distance to the workpiece W by outputting the control signal thus generated to each part of the laser processing apparatus L.

For example, when starting processing the work W, the control unit 101 reads the target output stored in the condition setting storage unit 102, outputs a control signal generated based on the target output to the excitation light source drive unit 112, Controls the generation of laser excitation light.

Further, when actually processing the work W, the control unit 101 reads a processing pattern (marking pattern) stored in the condition setting storage unit 102, and transmits a control signal generated based on the processing pattern to the laser beam. The near-infrared laser beam is outputted to the scanning unit 4 and scanned two-dimensionally. The control unit 101 exemplifies a “scanning control unit” in this embodiment in that it controls two-dimensional scanning of near-infrared laser light.

(Excitation light generation section 110)
The excitation light generation unit 110 is optically coupled to the excitation light source 111 with an excitation light source 111 that generates laser light according to a drive current, and an excitation light source drive unit 112 that supplies a drive current to the excitation light source 111. and an excitation light condensing section 113. The excitation light source 111 and the excitation light condenser 113 are fixed within an excitation casing (not shown). Although details are omitted, this excitation casing is made of a metal such as copper that has excellent thermal conductivity, and can efficiently radiate heat from the excitation light source 111.

Each part of the excitation light generation section 110 will be explained in order below.

The excitation light source drive unit 112 supplies a drive current to the excitation light source 111 based on the control signal output from the control unit 101. Although details will be omitted, the excitation light source drive unit 112 determines a drive current based on the target output determined by the control unit 101, and supplies the determined drive current to the excitation light source 111.

The excitation light source 111 is supplied with a drive current from the excitation light source drive unit 112 and oscillates laser light according to the drive current. For example, the excitation light source 111 is composed of a laser diode (LD) or the like, and an LD array or LD bar in which a plurality of LD elements are arranged in a straight line can be used. When an LD array or an LD bar is used as the excitation light source 111, laser light emitted from each element is output in a line shape and enters the excitation light condenser 113.

The excitation light condenser 113 condenses the laser beam output from the excitation light source 111 and outputs it as laser excitation light (excitation light). For example, the excitation light condenser 113 is composed of a focusing lens or the like, and has an entrance surface into which the laser beam is incident, and an exit surface through which the laser excitation light is output. The excitation light condenser 113 is optically coupled to the marker head 1 via the aforementioned optical fiber cable. Therefore, the laser excitation light output from the excitation light condenser 113 is guided to the marker head 1 via the optical fiber cable.

Note that the excitation light generation section 110 can be an LD unit or an LD module in which the excitation light source driving section 112, the excitation light source 111, and the excitation light condensing section 113 are incorporated in advance. Furthermore, the excitation light emitted from the excitation light generation section 110 (specifically, the laser excitation light output from the excitation light condensing section 113) can be made non-polarized, thereby preventing changes in the polarization state. There is no need to take this into account, which is advantageous in terms of design. In particular, regarding the configuration around the excitation light source 111, the LD unit itself, which bundles and outputs light obtained from an LD array in which several dozen LD elements are arranged using optical fibers, has a mechanism that makes the output light non-polarized. It is preferable to have one.

(other components)
The marker controller 100 also includes a distance measuring section 103 that measures the distance to the workpiece W via the distance measuring unit 5. The distance measurement section 103 is electrically connected to the distance measurement unit 5, and receives a signal related to the measurement result by the distance measurement unit 5 (at least a signal indicating the distance measurement light receiving position in the distance measurement light receiving section 5B). It is possible to receive.

Further, as will be described later, the laser processing apparatus L according to the present embodiment includes a non-coaxial camera 6 as a wide-area camera for capturing an image of the surface of the workpiece W. The control unit 101 in the marker controller 100 can perform processing based on images captured by the non-coaxial camera 6.

The marker controller 100 also includes a setting section 107 that sets information related to marking patterns. The settings in the setting unit 107 are read and used by the control unit 101 as a scanning control unit.

Note that the distance measurement section 103 and the setting section 107 may be configured by the control section 101. For example, the control unit 101 may also serve as at least one of the distance measurement unit 103 and the setting unit 107.

Details of the distance measuring section 103 and the setting section 107 will be described later.

<Marker head 1>
As described above, the laser excitation light generated by the excitation light generation section 110 is guided to the marker head 1 via the optical fiber cable. This marker head 1 includes a laser beam output section 2 that amplifies and generates laser light based on laser excitation light and outputs it, and a laser beam output section 2 that irradiates the surface of a workpiece W with the laser beam outputted from the laser beam output section 2. A laser beam scanning unit 4 that performs dimensional scanning, a laser beam guide unit 3 that configures an optical path from the laser beam output unit 2 to the laser beam scanning unit 4, and a distance measuring unit that emits and receives light through the laser beam scanning unit 4. A distance measuring unit 5 for measuring the distance to the surface of the workpiece W based on light is provided.

Here, the laser beam guide unit 3 according to the present embodiment not only constitutes an optical path, but also includes a Z scanner (focus adjustment unit) 33 that adjusts the focal position of the laser beam, and a guide light source that emits the guide light. It is made up of a combination of multiple members.

Further, the laser beam guide section 3 further includes an upstream side merging mechanism (guide light merging mechanism) 31 that merges the near-infrared laser beam output from the laser beam output section 2 and the guide light emitted from the guide light source 36; It has a downstream merging mechanism (distance-measuring light merging mechanism) 35 that merges the laser beam guided to the laser beam scanning section 4 and the distance-measuring light projected from the distance-measuring unit 5.

3A to 3B are block diagrams illustrating the schematic configuration of the marker head 1, and FIG. 4 is a perspective view illustrating the appearance of the marker head 1. 3A to 3B, FIG. 3A shows an example of processing a workpiece W using near-infrared laser light, and FIG. 3B shows a case of measuring the distance to the surface of the workpiece W using a distance measuring unit 5. is exemplified.

As illustrated in FIGS. 3A to 4, the marker head 1 includes a housing 10 in which at least a laser beam output section 2, a laser beam guide section 3, a laser beam scanning section 4, and a distance measuring unit 5 are provided. ing. This housing 10 has a substantially rectangular external shape as shown in FIG. The lower surface of the housing 10 is defined by a plate-shaped bottom plate 10a. The bottom plate 10a is provided with a transmission window 19 serving as a transmission window portion for emitting laser light from the marker head 1 to the outside of the marker head 1. The transmission window 19 is constructed by fitting a plate-shaped transparent member that can transmit near-infrared laser light, guide light, and distance measurement light into a through hole that penetrates the bottom plate 10a in the thickness direction.

In the following description, the longitudinal direction of the casing 10 in FIG. 4 will be simply referred to as the "longitudinal direction" or the "front-back direction," and the lateral direction of the casing 10 in FIG. This is sometimes referred to as the "left-right direction." Similarly, the height direction of the housing 10 in FIG. 4 may be simply referred to as the "height direction" or the "up-down direction."

FIG. 5 is a perspective view illustrating the configuration of the laser beam scanning section 4. As shown in FIG. Further, FIG. 6 is a cross-sectional view illustrating the configuration of the laser beam guide section 3, the laser beam scanning section 4, and the distance measuring unit 5, and FIG. 8 is a cross-sectional view illustrating an optical path connecting the laser beam guide section 3, the laser beam scanning section 4, and the distance measuring unit 5. FIG.

As illustrated in FIGS. 5 and 6, a partition portion 11 is provided inside the casing 10. As illustrated in FIGS. The internal space of the casing 10 is partitioned into one side and the other side in the longitudinal direction by the partition part 11.

Specifically, the partition portion 11 is formed into a flat plate shape extending in a direction perpendicular to the longitudinal direction of the casing 10 . Further, in the longitudinal direction of the housing 10, the partition portion 11 is arranged closer to one side in the longitudinal direction (the front side in FIG. 4) compared to the central portion of the housing 10 in the same direction.

Therefore, the space partitioned on one side in the longitudinal direction within the housing 10 has a shorter longitudinal dimension than the space partitioned on the other side in the longitudinal direction (the rear side in FIG. 4). Hereinafter, the space partitioned on the other side in the longitudinal direction within the housing 10 will be referred to as a first space S1, while the space partitioned on one side in the longitudinal direction will be referred to as a second space S2.

In this embodiment, a laser beam output section 2, some parts of the laser beam guide section 3, a laser beam scanning section 4, and a distance measuring unit 5 are arranged inside the first space S1. On the other hand, the main components of the laser beam guide section 3 are arranged inside the second space S2.

Specifically, the first space S1 is partitioned by the substantially flat base plate 12 into a space on one side in the transverse direction (the left side in FIG. 4) and a space on the other side (the right side in FIG. 4). . Parts constituting the laser light output section 2 are mainly arranged in the former space.

More specifically, among the parts constituting the laser beam output section 2, the optical parts 21, such as optical lenses and optical crystals, which are required to be sealed as airtight as possible, are fixed in the short direction in the first space S1. In the side space, it is arranged inside a housing space surrounded by the base plate 12 and the like.

On the other hand, among the parts constituting the laser beam output section 2, parts that do not necessarily need to be sealed tightly, such as electrical wiring and the heat sink 22 shown in FIG. It is arranged on the opposite side (the other side in the lateral direction in the first space S1).

Further, as illustrated in FIGS. 5 and 6, the laser beam scanning section 4 can be arranged on one side in the lateral direction with the base plate 12 in between, similarly to the optical component 21 in the laser beam output section 2. . Specifically, the laser beam scanning section 4 according to this embodiment is arranged adjacent to the partition section 11 described above in the longitudinal direction, and along the inner bottom surface of the housing 10 in the vertical direction.

Further, as shown in FIG. 6, the distance measuring unit 5, like the heat sink 22 in the laser beam output section 2, is arranged in the space on the other side in the lateral direction of the first space S1.

Furthermore, the components constituting the laser beam guide section 3 are mainly arranged in the second space S2. In this embodiment, most of the components constituting the laser light guide section 3 are housed in a space surrounded by the partition section 11 and the cover member 17 that partitions the front surface of the housing 10.

Note that, among the parts constituting the laser beam guide section 3, the downstream side merging mechanism 35 is arranged in the vicinity of the partition section 11 in the first space S1 (see FIG. 5). That is, in this embodiment, the downstream merging mechanism 35 is located near the boundary between the first space S1 and the second space S2.

Further, the base plate 12 is formed with a through hole (not shown) that penetrates the base plate 12 in the thickness direction. The laser beam guide section 3 and the laser beam scanning section 4 are optically coupled to the distance measuring unit 5 through this through hole. The base plate 12 has high rigidity and is less likely to deform than the housing 10 even after many years of use. Therefore, by fixing the ranging unit 5 to the base plate 12 instead of the housing 10 using a fastening member such as a screw, for example, the posture of the ranging unit 5 can be prevented from shifting due to long-term use, and the ranging accuracy can be improved. can prevent a decline in

Hereinafter, the configurations of the laser beam output section 2, the laser beam guide section 3, the laser beam scanning section 4, and the distance measuring unit 5 will be explained in order.

(Laser light output section 2)
The laser light output unit 2 generates near-infrared laser light for printing based on the laser excitation light generated by the excitation light generation unit 110, and also sends the near-infrared laser light to the laser light guide unit 3. is configured to print.

Specifically, the laser beam output unit 2 includes a laser oscillator 21a that generates a laser beam having a predetermined wavelength based on laser excitation light, amplifies the generated laser beam, and emits a near-infrared laser beam, and a laser oscillator 21a that generates a laser beam having a predetermined wavelength based on the laser excitation light. It includes a beam sampler 21b for separating a part of the emitted near-infrared laser light, and a power monitor 21c into which the near-infrared laser light separated by the beam sampler 21b is incident.

Although details are omitted, the laser oscillator 21a according to the present embodiment includes a laser medium that performs stimulated emission corresponding to laser excitation light to emit laser light, and a laser medium that emits laser light by performing stimulated emission corresponding to laser excitation light, and a It has a Q switch and a mirror that resonates the laser light pulsed by the Q switch.

In particular, in this embodiment, rod-shaped Nd:YVO ₄ (yttrium vanadate) is used as the laser medium. Thereby, the laser oscillator 21a can emit a laser beam (the above-mentioned near-infrared laser beam) having a wavelength of around 1064 nm as a laser beam. However, the present invention is not limited to this example, and other laser media such as YAG, YLF, GdVO ₄ doped with rare earth elements, etc. can also be used. Various solid laser media can be used depending on the purpose of the laser processing apparatus L.

Furthermore, the wavelength of the output laser light can be converted to an arbitrary wavelength by combining a wavelength conversion element with the solid-state laser medium. Furthermore, a so-called fiber laser may be used in which a fiber is used as an oscillator instead of a bulk solid-state laser medium.

Furthermore, the laser oscillator 21a may be configured by combining a solid laser medium such as Nd:YVO ₄ and a fiber. In that case, as in the case of using a solid-state laser medium, a laser with a short pulse width is emitted to suppress thermal damage to the workpiece W, while, as in the case of using a fiber, high output can be achieved. This makes it possible to realize faster printing processing.

The power monitor 21c detects the output of the near-infrared laser beam. The power monitor 21c is electrically connected to the marker controller 100 and can output its detection signal to the control unit 101 and the like.

(Laser light guide section 3)
The laser beam guide section 3 forms at least a part of a laser beam path P that guides the near-infrared laser beam emitted from the laser beam output section 2 to the laser beam scanning section 4 . In addition to a bend mirror 34 for forming such a laser beam path P, the laser beam guiding section 3 includes a Z scanner (focus adjustment section) 33, a guide light source (guide light emitting section) 36, and the like. All of these parts are provided inside the housing 10 (mainly in the second space S2).

The near-infrared laser beam incident from the laser beam output section 2 is reflected by the bend mirror 34 and passes through the laser beam guide section 3. A Z scanner 33 is arranged on the way to the bend mirror 34 for adjusting the focal position of the near-infrared laser beam. The near-infrared laser beam that passes through the Z scanner 33 and is reflected by the bend mirror 34 enters the laser beam scanning section 4 .

The laser optical path P configured by the laser beam guide section 3 can be divided into two with the Z scanner 33 serving as a focus adjustment section as the boundary. Specifically, the laser beam path P configured by the laser beam guide section 3 includes an upstream optical path Pu from the laser beam output section 2 to the Z scanner 33, and a downstream optical path Pd from the Z scanner 33 to the laser beam scanning section 4. , can be divided into .

More specifically, the upstream optical path Pu is provided inside the housing 10 and extends from the laser beam output section 2 to the Z scanner 33 via the above-mentioned upstream merging mechanism 31.

On the other hand, the downstream optical path Pd is provided inside the casing 10, and passes from the Z scanner 33 through the bend mirror 34 and the aforementioned downstream merging mechanism 35 in order to the laser beam scanning section 4. The first scanner 41 is reached.

In this way, inside the housing 10, the upstream merging mechanism 31 is provided in the middle of the upstream optical path Pu, and the downstream merging mechanism 35 is provided in the middle of the downstream optical path Pd.

Hereinafter, the configuration related to the laser beam guide section 3 will be explained in order.

-Guide light source 36-
The guide light source 36 is provided in the second space S2 inside the housing 10, and emits guide light for projecting a predetermined machining pattern onto the surface of the workpiece W. The wavelength band of the guide light is set to fall within the visible light range. As an example, the guide light source 36 according to the present embodiment emits red laser light having a wavelength of around 655 nm as the guide light. Therefore, when the guide light is emitted from the marker head 1, the user can visually recognize the guide light.

Specifically, the wavelength band of the guide light in this embodiment is preferably set to 645 nm or more and 660 nm or less. Therefore, the wavelength band of the guide light does not overlap with the near-infrared laser beam wavelength band.

Thus, in this embodiment, the wavelength of the guide light is set to be different from at least the wavelength of the near-infrared laser light. Further, as will be described later, the distance measurement light emitting section 5A in the distance measurement unit 5 emits distance measurement light having a wavelength different from that of the guide light and the near-infrared laser beam. Therefore, the distance measurement light, the guide light, and the laser light have different wavelengths, and the wavelength bands of the distance measurement light, guide light, and laser light do not overlap with each other.

Further, the guide light source 36 is arranged at approximately the same height as the upstream merging mechanism 31 in the second space S2, and emits a visible laser (guide light) toward the inner side of the casing 10 in the transverse direction. be able to. The guide light source 36 is also oriented such that the optical axis of the guide light emitted from the guide light source 36 and the upstream merging mechanism 31 intersect.

Note that "substantially the same height" as used herein means that the height positions are substantially the same when viewed from the bottom plate 10a forming the lower surface of the housing 10. In other descriptions, it refers to the height seen from the bottom plate 10a.

Therefore, for example, when guide light is emitted from the guide light source 36 in order to allow the user to visually recognize a processing pattern using near-infrared laser light, the guide light reaches the upstream merging mechanism 31 . The upstream merging mechanism 31 includes a dichroic mirror (not shown) as an optical component. As will be described later, this dichroic mirror reflects near-infrared laser light while transmitting guide light. As a result, the guide light that has passed through the dichroic mirror and the near-infrared laser light that has been reflected by the mirror merge and become coaxial.

Note that the guide light source 36 according to this embodiment is configured to emit guide light based on a control signal output from the control unit 101.

-Upstream side merging mechanism 31-
The upstream merging mechanism 31 is provided inside the housing 10 in the middle of the laser light path P from the laser light output section 2 to the laser light scanning section 4, with the laser light output section 2 as the starting point. The upstream side merging mechanism 31 is an example of the "guide light merging mechanism" in this embodiment.

Specifically, the upstream side merging mechanism 31 according to the present embodiment is located between the laser beam output section 2 and the Z scanner 33 as a focus adjustment section in the laser optical path P (specifically, side optical path Pu).

The upstream merging mechanism 31 causes the guide light emitted from the guide light source 36 serving as the guide light emitting section to merge into the upstream optical path Pu in the laser optical path P. By providing the upstream merging mechanism 31, the guide light emitted from the guide light source 36 and the near-infrared laser light in the upstream optical path Pu can be made coaxial.

As described above, the wavelength band of the guide light is set so as not to overlap at least the wavelength band of the near-infrared laser beam. Therefore, the upstream merging mechanism 31 can be configured using, for example, a dichroic mirror, as described above. The near-infrared laser beam and guide light coaxialized by the dichroic mirror propagate downward, pass through the Z scanner 33, and reach the bend mirror 34.

-Z Scanner 33-
The Z scanner 33 as a focus adjustment unit is disposed in the middle of the optical path constituted by the laser light guide unit 3, and can adjust the focal position of the near-infrared laser beam emitted from the laser light output unit 2. .

Specifically, the Z scanner 33 is provided inside the housing 10 in the middle of the optical path of the laser light path P from the upstream side merging mechanism 31 as a guide light merging mechanism to the laser beam scanning unit 4.

Specifically, as shown in FIGS. 3A and 3B, the Z scanner 33 according to the present embodiment includes an input lens 33a that transmits near-infrared laser light emitted from the laser light output section 2, and a laser beam that passes through the input lens 33a. a collimating lens 33b that allows the near-infrared laser beam to pass through, an output lens 33c that allows the near-infrared laser beam that has passed through the input lens 33a and the collimator lens 33b to pass, a lens drive unit 33d that moves the input lens 33a, It has a casing 33e that accommodates a lens 33a, a collimating lens 33b, and an exit lens 33c.

The entrance lens 33a is made of a plano-concave lens, and the collimating lens 33b and the exit lens 33c are made of a plano-convex lens. The entrance lens 33a, the collimating lens 33b, and the exit lens 33c are arranged so that their optical axes are coaxial with each other.

Furthermore, in the Z scanner 33, a lens driving section 33d moves the input lens 33a along the optical axis. This allows the relative distance between the input lens 33a and the output lens 33c to be changed while keeping the optical axes of the input lens 33a, collimator lens 33b, and output lens 33c coaxial with respect to the near-infrared laser beam passing through the Z scanner 33. can do. As a result, the focal position of the near-infrared laser beam irradiated onto the workpiece W changes.

Each part of the Z scanner 33 will be described in more detail below.

The casing 33e has a substantially cylindrical shape. As shown in FIGS. 3A and 3B, openings 33f for passing near-infrared laser light are formed at both ends of the casing 33e. Inside the casing 33e, the entrance lens 33a, the collimating lens 33b, and the exit lens 33c are vertically arranged in this order.

Of the entrance lens 33a, collimating lens 33b, and exit lens 33c, the collimating lens 33b and the exit lens 33c are fixed inside the casing 33e. On the other hand, the entrance lens 33a is provided so as to be movable in the vertical direction. The lens drive unit 33d includes, for example, a motor, and moves the entrance lens 33a in the vertical direction. This changes the relative distance between the entrance lens 33a and the exit lens 33c.

For example, assume that the distance between the input lens 33a and the output lens 33c is adjusted to be relatively short by the lens driving section 33d. In this case, since the convergence angle of the near-infrared laser beam passing through the output lens 33c becomes relatively small, the focal position of the near-infrared laser beam moves away from the transmission window 19 of the marker head 1.

On the other hand, it is assumed that the distance between the input lens 33a and the output lens 33c is adjusted to be relatively long by the lens driving section 33d. In this case, since the convergence angle of the near-infrared laser beam passing through the output lens 33c becomes relatively large, the focal position of the near-infrared laser beam approaches the transmission window 19 of the marker head 1.

Note that in the Z scanner 33, among the entrance lens 33a, collimating lens 33b, and exit lens 33c, the entrance lens 33a may be fixed inside the casing 33e, and the collimating lens 33b and the exit lens 33c may be movable in the vertical direction. good. Alternatively, the entrance lens 33a, collimator lens 33b, and exit lens 33c may all be movable in the vertical direction.

In this way, the Z scanner 33 as a focus adjustment section functions as a means for vertically scanning the near-infrared laser beam. Hereinafter, the scanning direction by the Z scanner 33 may be referred to as the "Z direction."

Note that the near-infrared laser beam passing through the Z scanner 33 is coaxial with the guide light emitted from the guide light source 36, as described above. Therefore, by operating the Z scanner 33, the focal position of not only the near-infrared laser beam but also the guide light can be adjusted.

Note that the Z scanner 33 according to this embodiment, particularly the lens drive section 33d in the Z scanner 33, is configured to operate based on a control signal output from the control section 101.

-Bend mirror 34-
The bend mirror 34 is provided in the middle of the downstream optical path Pd, and is arranged so as to bend the optical path Pd and direct it backward. As shown in FIG. 6, the bend mirror 34 is arranged at approximately the same height as the optical member 35a in the downstream merging mechanism 35, and reflects the near-infrared laser beam and guide light that have passed through the Z scanner 33. I can do it.

The near-infrared laser beam and guide light reflected by the bend mirror 34 propagate toward the rear, pass through the downstream merging mechanism 35, and reach the laser beam scanning section (specifically, the first scanner 41) 4. .

-Downstream merging mechanism 35-
The downstream merging mechanism 35 is provided inside the housing 10 in the laser beam path P between the upstream merging mechanism 31 as a guide light merging mechanism and the laser beam scanning section 4 . The downstream merging mechanism 35 is an example of a "distance-measuring light merging mechanism."

Specifically, the downstream merging mechanism 35 according to the present embodiment is located between the Z scanner 33 serving as a focus adjustment unit and the laser beam scanning unit 4 in the laser optical path P (specifically, the downstream merging mechanism 35 described above side optical path Pd).

The downstream merging mechanism 35 can cause the distance measuring light emitted from the distance measuring light emitting section 5A in the distance measuring unit 5 to merge at a midway point in the laser optical path P. The distance-measuring light that merges at the midway point is guided to the surface of the workpiece W via the laser beam scanning section 4.

In addition, the downstream merging mechanism 35 converts the distance measuring light reflected by the workpiece W (particularly the surface of the workpiece W) and returns along the downstream optical path Pd via the laser beam scanning section 4 into the distance measuring unit 5. The light can be guided to the distance light receiving section 5B.

By providing the downstream merging mechanism 35, the distance measuring light emitted from the distance measuring light emitting section 5A and the near-infrared laser beam and guide light in the downstream optical path Pd can be made coaxial. At the same time, by providing the downstream merging mechanism 35, among the distance measurement light emitted from the marker head 1 and reflected by the workpiece W, the distance measurement light that has returned to the marker head 1 is guided to the distance measurement light receiving section 5B. be able to.

The configuration of the downstream merging mechanism 35 will be described later.

(Laser beam scanning section 4)
As shown in FIG. 3A, the laser beam scanning section 4 irradiates the workpiece W with a laser beam (near infrared laser beam) emitted from the laser beam output section 2 and guided by the laser beam guide section 3. It is configured to two-dimensionally scan the surface of the workpiece W.

In the example shown in FIG. 5, the laser beam scanning section 4 is configured as a so-called two-axis galvano scanner. That is, this laser beam scanning section 4 includes a first scanner 41 for scanning near-infrared laser beam incident from the laser beam guide section 3 in a first direction, and a near-infrared laser scanned by the first scanner 41. It has a second scanner 42 for scanning light in a second direction.

Here, the second direction refers to a direction substantially orthogonal to the first direction. Therefore, the second scanner 42 can scan with near-infrared laser light in a direction substantially orthogonal to the first scanner 41. In this embodiment, the first direction is equal to the front-rear direction (the longitudinal direction of the housing 10), and the second direction is equal to the left-right direction (the lateral direction of the housing 10). Hereinafter, the first direction will be referred to as the "X direction", and the second direction orthogonal thereto will be referred to as the "Y direction". Both the X direction and the Y direction are perpendicular to the above-mentioned Z direction.

The first scanner 41 has a first mirror 41a at its tip. The first mirror 41a is arranged at substantially the same height as the bend mirror 34 and the optical member 35a, and behind the optical member 35a. Therefore, as shown in FIG. 5, the bend mirror 34, the optical member 35a, and the first mirror 41a are arranged in a line along the front-back direction (the longitudinal direction of the housing 10).

The first mirror 41a is also rotationally driven by a motor (not shown) built into the first scanner 41. This motor can rotate the first mirror 41a around a rotation axis extending in the vertical direction. By adjusting the rotational attitude of the first mirror 41a, the angle of reflection of the near-infrared laser beam by the first mirror 41a can be adjusted.

Similarly, the second scanner 42 has a second mirror 42a at its tip. The second mirror 42a is located at approximately the same height as the first mirror 41a in the first scanner 41 and to the right of the first mirror 41a. Therefore, as shown in FIG. 6, the first mirror 41a and the second mirror 42a are arranged along the left-right direction (the lateral direction of the housing 10).

The second mirror 42a is also rotationally driven by a motor (not shown) built into the second scanner 42. This motor can rotate the second mirror 42a around a rotation axis extending in the front-rear direction. By adjusting the rotational attitude of the second mirror 42a, the angle of reflection of the near-infrared laser beam by the second mirror 42a can be adjusted.

Therefore, when near-infrared laser light enters the laser beam scanning unit 4 from the downstream merging mechanism 35, the near-infrared laser light is transmitted to the first mirror 41a in the first scanner 41 and the second mirror in the second scanner 42. 42a, and exit to the outside of the marker head 1 through the transmission window 19.

At this time, by operating the motor of the first scanner 41 and adjusting the rotational attitude of the first mirror 41a, it becomes possible to scan the surface of the workpiece W with the near-infrared laser beam in the first direction. . At the same time, by operating the motor of the second scanner 42 and adjusting the rotational attitude of the second mirror 42a, it becomes possible to scan the surface of the workpiece W with the near-infrared laser beam in the second direction.

Further, as described above, the laser beam scanning unit 4 receives not only the near-infrared laser beam but also the guide light that has passed through the optical member 35a of the downstream merging mechanism 35, or the distance measuring light that has been reflected by the optical member 35a. will also be incident. The laser beam scanning unit 4 according to the present embodiment can two-dimensionally scan the guide light or distance measurement light that has entered by operating the first scanner 41 and the second scanner 42, respectively.

Note that the rotational postures that the first mirror 41a and the second mirror 42a can take are basically such that when near-infrared laser light is reflected by the second mirror 42a, the reflected light passes through the transmission window 19. (See also FIGS. 7 and 8).

In this way, the laser beam scanning section 4 according to the present embodiment is electrically controlled by the control section 101 serving as a scanning control section, thereby emitting near-infrared laser light to a processing area set on the surface of the workpiece W. A predetermined processing pattern (marking pattern) can be formed within the processing area by irradiation.

(Distance measurement unit 5)
As shown in FIG. 3B, the distance measuring unit 5 projects distance measuring light via the laser beam scanning section 4, and irradiates the surface of the workpiece W with the distance measuring light. The distance measuring unit 5 also receives distance measuring light reflected by the surface of the workpiece W via the laser beam scanning section 4.

The distance measurement unit 5 is mainly divided into a module for projecting distance measurement light and a module for receiving distance measurement light. Specifically, the ranging unit 5 includes a ranging light emitting section 5A configured as a module for projecting ranging light, and a ranging light receiving section configured as a module for receiving ranging light. It is equipped with 5B.

Of these, the distance measuring light emitting unit 5A is provided inside the housing 10, and emits the distance measuring light for measuring the distance from the marker head 1 to the surface of the workpiece W in the laser processing device L with the laser beam. The light is emitted toward the scanning section 4.

On the other hand, the distance measuring light receiving section 5B is provided inside the housing 10 similarly to the distance measuring light emitting section 5A, and is reflected on the surface of the workpiece W to the laser beam scanning section 4 and the downstream merging mechanism 35. It receives the distance measuring light that returns through the .

Further, the ranging unit 5 includes a support base 50 that supports the ranging light emitting section 5A and the ranging light receiving section 5B from below, and is fixed inside the housing 10 via the support base 50. There is.

As described above, the ranging unit 5 is provided in the space on the other side in the lateral direction in the first space S1. As shown in FIG. 7, the ranging unit 5 emits ranging light forward along the longitudinal direction of the housing 10, and receives ranging light propagating substantially backward along the longitudinal direction.

Furthermore, the distance measuring unit 5 is optically coupled to the laser beam guide section 3 via the aforementioned optical member 35a. As described above, the ranging unit 5 projects the ranging light along the longitudinal direction of the housing 10. On the other hand, the optical member 35a is configured to reflect the ranging light propagated along the lateral direction of the housing 10 rather than the longitudinal direction.

Therefore, a bend mirror 59 is provided inside the housing 10 to form an optical path connecting the distance measuring unit 5 and the optical member 35a (see FIGS. 6 and 7).

Therefore, the distance measuring light that has entered the bend mirror 59 from the distance measuring light emitting section 5A is reflected by the mirror 59 and enters the optical member 35a. On the other hand, the distance measuring light that returns to the laser beam scanning section 4 and is reflected by the optical member 35a enters the bend mirror 59, is reflected by the same mirror 59, and enters the distance measuring light receiving section 5B.

Hereinafter, the configuration of each part forming the ranging unit 5 will be explained in order.

-Distance measurement light emitting section 5A-
The distance measuring light emitting unit 5A is provided inside the housing 10 and is configured to emit distance measuring light for measuring the distance from the marker head 1 in the laser processing device L to the surface of the workpiece W. ing.

Specifically, the distance measurement light emitting unit 5A includes the above-mentioned distance measurement light source 51 and light projection lens 52, a casing 53 that accommodates these, and a pair of distance measurement light that guides the distance measurement light condensed by the projection lens 52. It has guide plates 54L and 54R. The distance measuring light source 51, the light projection lens 52, and the guide plates 54L and 54R are lined up in order from the rear side of the housing 10, and the direction in which they are lined up is substantially the same as the longitudinal direction of the housing 10.

The casing 53 is formed in a cylindrical shape extending along the longitudinal direction of the casing 10 and the support base 50, and has a distance measuring light source 51 at one end in the same direction, that is, one end corresponding to the rear side of the casing 10. is attached, while a light projecting lens 52 is attached to the other end corresponding to the front side of the housing 10. The space between the distance measuring light source 51 and the light projecting lens 52 is substantially hermetically sealed.

The distance measurement light source 51 emits distance measurement light toward the front side of the housing 10 according to a control signal input from the control unit 101. Specifically, the distance measuring light source 51 can emit laser light in the visible light range as the distance measuring light. In particular, the ranging light source 51 according to this embodiment emits red laser light having a wavelength of around 690 nm as ranging light.

Specifically, the wavelength band of the ranging light in this embodiment is preferably set to 680 nm or more and 695 nm or less. Therefore, the wavelength band of the ranging light does not overlap with the wavelength bands of the near-infrared laser beam and the guide light.

The distance measurement light source 51 is also fixed in such a position that the optical axis Ao of the red laser beam emitted as the distance measurement light is along the longitudinal direction of the casing 53. Therefore, the optical axis Ao of the ranging light is along the longitudinal direction of the housing 10 and the support base 50, passes through the center of the light projecting lens 52, and reaches the outside of the casing 53.

The light projecting lens 52 is located between the light receiving lens 57 and the pair of light receiving elements 56L and 56R in the ranging light receiving section 5B in the longitudinal direction of the support base 50. The light projection lens 52 is oriented such that the optical axis Ao of the ranging light passes through it.

The light projection lens 52 can be, for example, a plano-convex lens, and can be fixed with a spherical convex surface facing the outside of the casing 53. The light projection lens 52 collects the distance measurement light emitted from the distance measurement light source 51 and emits it to the outside of the casing 53 . The distance measuring light emitted to the outside of the casing 53 reaches between the guide plates 54L and 54R.

The guide plates 54L and 54R are configured as a pair of members lined up in the lateral direction of the support base 50, and each can be a plate-shaped body extending in the longitudinal direction of the support base 50. A space for emitting ranging light is defined between one guide plate 54L and the other guide plate 54R. The distance measuring light emitted to the outside of the casing 53 passes through the thus partitioned space and is output.

Therefore, the distance measurement light emitted from the distance measurement light source 51 passes through the space inside the casing 53, the center of the projection lens 52, and the space between the guide plates 54L and 54R, and exits the distance measurement unit 5. Output. The distance measuring light thus output is reflected by the bend mirror 59 and the optical member 35a in the downstream merging mechanism 35, and enters the laser beam scanning section 4.

The distance measuring light incident on the laser beam scanning unit 4 is reflected in order by the first mirror 41a of the first scanner 41 and the second mirror 42a of the second scanner 42, and is reflected from the transmission window 19 to the outside of the marker head 1. It will be emitted to.

As described in the description of the laser beam scanning unit 4, by adjusting the rotational attitude of the first mirror 41a of the first scanner 41, the surface of the workpiece W can be scanned with the distance measuring light in the first direction. . At the same time, by operating the motor of the second scanner 42 and adjusting the rotational attitude of the second mirror 42a, it becomes possible to scan the surface of the workpiece W with the distance measuring light in the second direction.

The distance measuring light thus scanned is reflected on the surface of the workpiece W. A part of the distance measuring light thus reflected (hereinafter also referred to as "reflected light") enters the inside of the marker head 1 through the transmission window 19. The reflected light that has entered the interior of the marker head 1 returns to the laser beam guide section 3 via the laser beam scanning section 4 . Since the reflected light has the same wavelength as the distance measuring light, it is reflected by the optical member 35a of the downstream merging mechanism 35 in the laser beam guide section 3 and enters the distance measuring unit 5 via the bend mirror 59.

-Distance measurement light receiving section 5B-
The distance measurement light receiving section 5B is provided inside the housing 10, and receives distance measurement light (equivalent to the above-mentioned "reflected light") emitted from the distance measurement light emission section 5A and reflected by the workpiece W. is configured to do so.

Specifically, the ranging light receiving section 5B includes a pair of light receiving elements 56L and 56R and a light receiving lens 57. The pair of light-receiving elements 56L and 56R are each placed at the rear end of the support base 50, while the light-receiving lens 57 is each placed at the front end of the support base 50. Therefore, the pair of light receiving elements 56L, 56R and the light receiving lens 57 are arranged substantially along the longitudinal direction of the housing 10 and the support base 50.

The pair of light receiving elements 56L and 56R are arranged inside the housing 10 so that their respective optical axes sandwich the optical axis Ao of the ranging light in the ranging light emitting section 5A. The pair of light receiving elements 56L and 56R each receive the reflected light returned to the laser beam scanning section 4.

Specifically, the pair of light receiving elements 56L and 56R are arranged in a direction perpendicular to the optical axis Ao of the ranging light emitting section 5A. In this embodiment, the direction in which the pair of light receiving elements 56L and 56R are arranged is equal to the lateral direction of the housing 10 and the support base 50, that is, the left-right direction. In the same direction, one light receiving element 56L is arranged on the left side of the ranging light source 51, and the other light receiving element 56R is arranged on the right side of the ranging light source 51.

The pair of light-receiving elements 56L and 56R each have a light-receiving surface directed diagonally forward, detect the light-receiving position of the reflected light on each light-receiving surface, and generate a signal (detection signal) indicating the detection result. Output. Detection signals output from each of the light receiving elements 56L and 56R are input to the marker controller 100 and reach the distance measuring section 103.

Examples of elements that can be used as the light receiving elements 56L and 56R include a CMOS image sensor made of a complementary MOS (CMOS), a CCD image sensor made of a charge-coupled device (CCD), and a light position sensor. Examples include a sensor (Position Sensitive Detector: PSD).

In this embodiment, each of the light receiving elements 56L and 56R is configured using a CMOS image sensor. In this case, each of the light-receiving elements 56L and 56R can detect not only the light-receiving position of the reflected light but also the distribution of the amount of light received (light-receiving waveform). That is, when each light receiving element 56L, 56R is configured using a CMOS image sensor, pixels are arranged at least in the left and right direction on each light receiving surface. In this case, each of the light receiving elements 56L and 56R can read and amplify a signal for each pixel and output it to the outside. The intensity of the signal at each pixel is determined based on the intensity of the reflected light at the spot when the reflected light forms a spot on the light receiving surface.

Note that when each light receiving element 56L, 56R is configured using an element capable of detecting the distribution of received light amount (received light waveform), such as a CMOS image sensor, the magnitude of the received light amount in each light receiving element 56L, 56R is measured. The intensity of the distance light, that is, the intensity of the distance measurement light emitted from the distance measurement light emitting unit 5A (hereinafter also referred to as the "projection light amount"), and the gain when amplifying the signal for each pixel (hereinafter referred to as this) (also referred to as "light receiving gain"). In addition to the gain, adjustment can be made using the exposure time of each light receiving element 56L, 56R.

The pair of light receiving elements 56L and 56R according to this embodiment can detect at least the peak position indicating the light receiving position of reflected light and the amount of received reflected light. As an index indicating the amount of received light, for example, the height of a peak in the distribution of the amount of received reflected light can be used. Instead of this, a total value, average value, or integral value of the received light amount distribution may be used.

Furthermore, in this embodiment, the peak position of the received light amount distribution (the peak position of the spot) is used as an index indicating the receiving position of the reflected light, but instead of this, the barycenter position of the received light amount distribution may also be used. good.

The light-receiving lens 57 is arranged inside the housing 10 so that the optical axes of the pair of light-receiving elements 56L and 56R pass through it. The light receiving lens 57 is also provided in the middle of the optical path from the downstream merging mechanism 35 to the pair of light receiving elements 56L, 56R, and directs the reflected light that has passed through the downstream merging mechanism 35 to the pair of light receiving elements 56L, 56R, respectively. The light can be focused on the light receiving surface.

The light-receiving lens 57 collects the reflected light that has returned to the laser beam scanning section 4, and forms a spot of the reflected light on the light-receiving surface of each of the light-receiving elements 56L and 56R. Each light receiving element 56L, 56R outputs a signal indicating the peak position of the spot thus formed and the amount of received light to the distance measuring section 103.

The laser processing device L basically measures the distance to the surface of the workpiece W based on the light receiving position of the reflected light (in this embodiment, the peak position of the spot) on the light receiving surface of each of the light receiving elements 56L and 56R. can do. A so-called triangulation method is used to measure the distance.

-About distance measurement method-
FIG. 9 is a diagram illustrating the triangulation method. In FIG. 9, only the distance measuring unit 5 is illustrated, but the following explanation is also common to the case where the distance measuring light is emitted via the laser beam scanning section 4 as described above.

As illustrated in FIG. 9, when distance measuring light is emitted from the distance measuring light source 51 in the distance measuring light emitting section 5A, the surface of the workpiece W is irradiated with the distance measuring light. When the distance measuring light is reflected by the work W, the reflected light (particularly the diffuse reflected light) will propagate approximately isotropically if the influence of specular reflection is removed.

The reflected light that propagates in this way includes a component that enters the light receiving element 56L via the light receiving lens 57, but depending on the distance between the marker head 1 and the workpiece W, the amount of the incident light that enters the light receiving element 56L varies. The angle of incidence will increase or decrease. When the angle of incidence on the light-receiving element 56L increases or decreases, the light-receiving position on the light-receiving surface 56a shifts.

In this way, the distance between the marker head 1 and the workpiece W and the light receiving position on the light receiving surface 56a are related in a predetermined relationship. Therefore, by understanding this relationship in advance and storing it in the marker controller 100, for example, it is possible to calculate the distance between the marker head 1 and the workpiece W from the light receiving position on the light receiving surface 56a. Such a calculation method is nothing but a method using a so-called triangulation method.

That is, the distance measuring section 103 described above measures the distance from the laser processing device L to the surface of the workpiece W using a triangular distance measuring method based on the light receiving position of the distance measuring light in the distance measuring light receiving section 5B.

Specifically, the above-mentioned condition setting storage unit 102 stores in advance the relationship between the light receiving position on the light receiving surface 56a and the distance from the marker head 1 to the surface of the workpiece W. On the other hand, a signal indicating the light receiving position of the distance measuring light in the distance measuring light receiving section 5B, specifically, the peak position of the spot formed on the light receiving surface 56a by the reflected light of the distance measuring light is input to the distance measuring section 103. be done.

The distance measuring unit 103 measures the distance to the surface of the workpiece W based on the input signal and the relationship stored in the condition setting storage unit 102. The measured values thus obtained are inputted to, for example, the control unit 101 and used by the control unit 101 to control the Z scanner 33 and the like.

For example, the laser processing device L automatically or manually determines a portion (print point) to be processed by the marker head 1 on the surface of the workpiece W. Next, before executing the printing process, the laser processing device L measures the distance to each printing point (more precisely, the distance measuring point set around the printing point) and measures the distance corresponding to the measured distance. The control parameters of the Z scanner 33 are determined so that the focal position is achieved. The laser processing device L operates the Z scanner 33 based on the control parameters thus determined, and then performs printing processing on the workpiece W using a near-infrared laser beam.

<About processing procedure of workpiece W>
Hereinafter, a procedure for processing a workpiece W by the laser processing device L will be described as a specific example of using the near-infrared laser beam, distance measuring light, and guide light. FIG. 10 is a flowchart illustrating the processing procedure for the workpiece W.

The control process illustrated in FIG. 10 is executed by a control unit 101 that can control the excitation light generation unit 110, the laser light output unit 2, the Z scanner 33, the laser light scanning unit 4, the ranging light emission unit 5A, and the guide light source 36. It is possible.

First, in step S101, processing conditions for laser processing are set by the user operating the operating terminal 800. The processing conditions set in step S101 include, for example, the contents of character strings and figures (marking patterns) to be printed on the surface of the workpiece W, and the layout of such character strings.

In the subsequent step S102, the control unit 101 determines a location on the surface of the workpiece W at which the distance from the marker head 1 is to be measured (hereinafter also referred to as "measurement location") based on the processing conditions set in step S101. Decide on multiple locations.

In subsequent step S103, the control unit 101 measures the distance from the laser processing device L to the surface of the workpiece W via the distance measuring unit 103 by controlling the distance measuring light emitting unit 5A.

Specifically, in this step S103, the control unit 101 causes the ranging light emitting unit 5A to emit ranging light to each measurement location determined in step S102, and the reflected light is transmitted to the ranging light receiving unit 5B. The light is received by Then, a signal indicating the receiving position of the reflected light in the distance measuring light receiving section 5B is input to the distance measuring section 103, and the distance measuring section 103 measures the distance to the surface of the workpiece W. The distance measurement unit 103 inputs a signal indicating the distance thus measured to the control unit 101.

In subsequent step S104, the control unit 101 determines control parameters for the Z scanner 33 based on the measurement results in step S103, that is, the distance measurements at each measurement point, so that the focal position corresponds to each measurement value. .

Specifically, in step S104, the control unit 101 determines the control parameters of the lens drive unit 33d at each measurement location, that is, the relative distance between the input lens 33a and the output lens 33c at each measurement location.

Note that both the upstream merging mechanism 31 and the downstream merging mechanism 35 are arranged on the way from the laser beam output section 2 to the laser beam scanning section 4. The upstream merging mechanism 31 makes the optical axes of the guide light and the near-infrared laser beam coaxial, and the downstream merging mechanism 35 makes the optical axes of the ranging light and the near-infrared laser beam coaxial. Therefore, by controlling the laser beam scanning section 4 by the control section 101, it is possible to two-dimensionally scan not only the near-infrared laser beam but also the guide light and the distance measuring light.

As an example of two-dimensional scanning of the guide light by the laser beam scanning section 4, the control section 101 executes step S105 following step S104. Specifically, in this step S105, the control unit 101 adjusts the focal position at each measurement location via the Z scanner 33, and after adjusting the focal position by the Z scanner 33, the control unit 101 moves the workpiece W via the guide light source 36. A guide light is irradiated onto the surface of the At the same time, the control unit 101 traces the marking pattern using the guide light emitted from the guide light source 36 by controlling the laser beam scanning unit 4 .

Note that an upstream merging mechanism 31 for merging the guide light with the near-infrared laser beam is provided upstream of the Z scanner 33. Therefore, by adjusting the focal position of the near-infrared laser beam using the Z scanner 33, it is possible to adjust the focal position of not only the near-infrared laser beam but also the guide light.

Further, tracing of the marking pattern by the guide light is repeatedly performed by appropriately controlling the laser beam scanning section 4. As a result, the marking pattern is continuously displayed on the surface of the workpiece W due to the afterimage effect of the human eye. At this time, in order to make the continuous display by the afterimage effect effective, it is conceivable to set the scanning speed of the guide light to the minimum speed at which the afterimage phenomenon occurs or higher. On the other hand, depending on conditions such as the material of the workpiece W and the output of the near-infrared laser beam, the scanning speed of the near-infrared laser beam may become excessively slow during printing. In response to this, the scanning speed of the guide light is set to a speed faster than the scanning speed of the near-infrared laser beam, that is, a speed higher than the minimum speed at which the afterimage phenomenon occurs.

In the subsequent step S106, the control unit 101 completes the settings related to the marking pattern, and executes printing processing based on the settings. Note that instead of this step S106, the settings related to the marking pattern may be transferred to the condition setting storage unit 102 or the operation terminal 800 and stored.

As already explained, the laser processing device L according to the present embodiment makes the guide light and the distance measurement light coaxial with the laser optical path P, so that in addition to the near-infrared laser light, the guide light and the distance measurement light can be It enables two-dimensional scanning of light.

However, if the guide light source 36 is made coaxial with the laser optical path P and the distance measuring unit 5 is also made coaxial, at least a part of the distance measuring light reflected on the surface of the workpiece W will be transmitted to the distance measuring unit 5. Instead, the light returns to the guide light source 36, and the amount of light received by the distance measurement light receiving section 5B of the distance measurement unit 5 may decrease. Such a decrease in the amount of received light is inconvenient because it leads to a decrease in measurement accuracy.

As a result of extensive studies, the inventors of the present application devised a configuration of the downstream side merging mechanism 35 as a distance measurement light merging mechanism in which the distance measurement light, the guide light, and the near-infrared laser light merge. So, I was able to overcome the above-mentioned inconvenience.

The configuration of the downstream merging mechanism 35 will be described in detail below.

<About the configuration of the downstream merging mechanism 35>
FIG. 11 is a perspective view illustrating the configuration of the downstream merging mechanism 35 viewed from the rear, and FIG. 12 is a perspective view illustrating the configuration of the downstream merging mechanism 35 viewed from the front. Further, FIG. 13A is a diagram illustrating the reflectance of the laser beam entrance surface 351 according to the first embodiment, and FIG. 13B is a diagram illustrating the reflectance of the laser beam exit surface 352 according to the first embodiment. be. Further, FIG. 14A is a diagram illustrating the optical path of near-infrared laser light and guide light in the downstream merging mechanism 35, and FIG. 14B is a diagram illustrating the optical path of the ranging light in the downstream merging mechanism 35. .

As described above, the wavelength band of the ranging light is set so as not to overlap the wavelength bands of the near-infrared laser beam and the guide light. Therefore, similarly to the upstream merging mechanism 31, the downstream merging mechanism 35 can be configured using an optical member 35a made of a dichroic mirror or the like.

Specifically, the downstream side merging mechanism 35 as a ranging light upstream merging mechanism has as main components an optical member 35a that guides the ranging light reflected on the surface of the workpiece W to the ranging light receiving section 5B; It has a holder 35b that holds the optical member 35a and is fixed to the housing 10.

The optical member 35a forming the downstream merging mechanism 35 selectively reflects or transmits only the wavelength band of the distance measuring light among the respective wavelength bands of the near-infrared laser beam, the guide light, and the distance measuring light. , the distance measuring light can be guided to the distance measuring light receiving section 5B.

Specifically, the optical member 35a is made of approximately disk-shaped glass, and the surface of the glass is coated to selectively reflect or transmit only the wavelength band of the distance measuring light. . Here, as illustrated in FIGS. 14A and 14B, the front and back surfaces of the optical member 35a include a laser light entrance surface 351 into which near-infrared laser light and guide light enter, and a near-infrared light entrance surface 351 into which near-infrared laser light and guide light enter. A laser light emitting surface 352 is provided through which the external laser light and the guide light are transmitted through the optical member 35a and emitted.

The aforementioned coating process is, for example, a vapor deposition process, and is applied to both the laser light incident surface 351 and the laser light emitting surface 352. Through this coating treatment, the optical member 35a according to the present embodiment (particularly the first embodiment) selectively reflects only the distance measurement light, while transmitting the respective wavelength bands of the near-infrared laser light and the guide light. be able to.

Moreover, the holder 35b is formed in a substantially cylindrical shape, and can be fitted with a substantially disc-shaped optical member 35a and fixed therein. As illustrated in FIGS. 6 and 7, the holder 35b is fitted into a through hole 11a provided in the partition portion 11. This through hole 11a communicates the second space S2 and the first space S1, and by fitting the holder 35b into the through hole 11a, the laser beam guide section 3 and the laser beam scanning section 4 are optically connected. Can be combined.

More specifically, the holder 35b is disposed at approximately the same height position as the second bend mirror 34 and behind the second bend mirror 34, and the holder 35b is arranged so that the housing 10 is placed on the left side in the lateral direction.

The holder 35b is also fixed in a posture in which the optical axis of the optical member 35a is tilted diagonally backward to the right (particularly in a posture tilted at 45 degrees with respect to the front-back direction), as shown in FIG. 6 and the like. As a result, the mirror surface on one side of the optical member 35a (laser light incidence surface 351 described below) is directed toward the second bend mirror 34, and the mirror surface on the other side of the optical member 35a (laser light output surface 352 described below) is directed toward the second bend mirror 34. , and is directed toward the through hole 12a of the base plate 12.

Therefore, as shown in FIGS. 14A and 14B, near-infrared laser light and guide light are incident on one mirror surface (laser light entrance surface 351) of the optical member 35a through the through hole 11a of the partition part 11. On the other hand, the distance measuring light is incident on the mirror surface (laser light emitting surface 352) on the other side via the through hole 12a.

The specific reflectance of the optical member 35a is as illustrated in FIGS. 13A and 13B. In each figure, the parts surrounded by broken lines illustrate the wavelength bands of the guide light, distance measuring light, and near-infrared laser light (printing laser light).

As shown in FIGS. 13A and 13B, the laser light entrance surface 351 and the laser light exit surface 352 according to the first embodiment are both configured to transmit the wavelength band of the guide light and the near-infrared laser light. ing.

Specifically, the optical member 35a according to the first embodiment has reflectances corresponding to the respective wavelength bands of the guide light and the near-infrared laser light on both the laser light entrance surface 351 and the laser light exit surface 352. It is set to essentially 0%. With this setting, the guide light and the near-infrared laser beam that have entered the laser light entrance surface 351 will pass through the laser light entrance surface 351. The guide light and near-infrared laser light that have passed through the laser light entrance surface 351 pass through the inside of the optical member 35a while being refracted, and reach the laser light exit surface 352. The guide light and near-infrared laser beam that have reached the laser beam exit surface 352 pass through the laser beam entrance surface 351 and are emitted to the outside (see FIG. 14A). The guide light and near-infrared laser light thus emitted are irradiated onto the surface of the workpiece W via the laser light scanning section 4.

On the other hand, the laser light emitting surface 352 according to the first embodiment selectively reflects only the wavelength band of the ranging light, as shown in FIG. 13B. On the other hand, the laser light emitting surface 352 according to the first embodiment is configured to transmit the wavelength band of the ranging light, as shown in FIG. 13A.

Specifically, in the optical member 35a according to the first embodiment, the reflectance corresponding to the wavelength band of the distance measuring light is substantially 100% (more specifically, 95% or more and 100% or more) on the laser light emitting surface 352. (less than %). With this setting, most of the ranging light incident on the laser beam output surface 352 will be reflected by the laser beam output surface 352 (see FIG. 14B). The distance measuring light thus reflected becomes coaxial with the guide light and the near-infrared laser light, and is irradiated onto the surface of the workpiece W via the laser light scanning unit 4. The distance measuring light reflected by the surface returns to the optical member 35a via the laser beam scanning section 4, is reflected again by the laser beam output surface 352, and returns to the distance measuring unit 5.

However, it is technically not easy to set the reflectance of the laser light emitting surface 352 to exactly 100%. Therefore, a small portion of the ranging light incident on the laser light emitting surface 352 passes through the laser light emitting surface 352 without being reflected by the laser light emitting surface 352. The distance measuring light that has passed through the laser beam exit surface 352 passes through the inside of the optical member 35a while being refracted, and reaches the laser beam entrance surface 351.

Here, in the optical member 35a according to the first embodiment, the reflectance corresponding to the wavelength band of the ranging light is substantially 0% (more specifically, 0% or more and 5%) on the laser light incident surface 351. (less than). With this setting, the distance measurement light that has passed through the laser beam exit surface 352 and reached the laser beam entrance surface 351 is suppressed from being reflected on the laser beam entrance surface 351, and is emitted from the laser beam entrance surface 351 to the outside. Become so.

Note that the distance measurement light that enters the laser beam output surface 352 from the distance measurement unit 5 and the distance measurement light that is reflected by the laser beam output surface 352 and returns to the distance measurement unit 5 are both separated as shown in FIG. In both cases, the light propagates along the left-right direction (the lateral direction of the housing 10) when the housing 10 is viewed from above. This propagation direction is perpendicular to the propagation direction of the near-infrared laser beam and guide light that propagate from the laser beam guide section 3 to the laser beam scanning section 4.

<About the effects of the downstream merging mechanism 35>
As explained above, the guide light and the distance measurement light are each made coaxial with the near-infrared laser light for processing, so that the guide light and the distance measurement light can be scanned by the laser beam scanning section 4. There is.

Specifically, the upstream side merging mechanism 31 as a guide light merging mechanism is arranged in the middle of the laser optical path P connecting the laser beam output section 2 and the laser beam scanning section 4, and the downstream side merging mechanism 31 as a ranging light merging mechanism The side merging mechanism 35 is arranged between the upstream merging mechanism 31 and the laser beam scanning section 4 in the laser optical path P. With this arrangement, the distance measuring light reflected on the surface of the workpiece W and returned to the marker head 1 will reach the downstream merging mechanism 35 before reaching the upstream merging mechanism 31.

Here, as illustrated in FIG. 13B, the optical member 35a constituting the downstream merging mechanism 35 is configured to perform distance measurement light in each wavelength band of the near-infrared laser light for processing, the guide light, and the distance measurement light. The distance measuring light is guided to the distance measuring light receiving section 5B by selectively reflecting or transmitting only the wavelength band. With this configuration, it is possible to suppress the propagation of the distance measurement light (in particular, the reflected light of the distance measurement light) to the guide light source 36, and increase the amount of light received by the distance measurement light receiving section 5B. This makes it possible to suppress a decrease in measurement accuracy.

Further, as illustrated in FIG. 14B, the laser light emitting surface 352 of the optical member 35a can reflect the distance measuring light and guide the distance measuring light to the laser beam scanning section 4 or the distance measuring light receiving section 5B. can. However, it is technically not easy to set the reflectance of the laser beam emitting surface 352 to exactly 100%, as illustrated in FIG. 13B. Therefore, a small portion of the ranging light incident on the laser light emitting surface 352 passes through the laser light emitting surface 352 without being reflected by the laser light emitting surface 352. The distance measuring light that has passed through the laser beam exit surface 352 passes through the inside of the optical member 35a while being refracted, and reaches the laser beam entrance surface 351.

If the distance measuring light that has reached the laser beam incident surface 351 is reflected by the laser beam incident surface 351 and returns to the distance measuring light receiving section 5B, the distance measuring light receiving section 5B will not be able to emit the laser beam. The distance measuring light reflected by the surface 352 and the laser beam entrance surface 351 both return. In this case, the light receiving position in the distance measuring light receiving section 5B may become blurred. This is undesirable because it leads to a decrease in measurement accuracy.

Therefore, as illustrated in FIG. 13A, the laser light entrance surface 351 transmits the wavelength band of the ranging light without reflecting it. As a result, the distance measurement light that has passed through the laser beam exit surface 352 and reached the laser beam entrance surface 351 is suppressed from being reflected on the laser beam entrance surface 351, and is emitted from the laser beam entrance surface 351 to the outside. Become. Thereby, blurring of the light receiving position in the distance measuring light receiving section 5B can be suppressed, and a decrease in measurement accuracy can be suppressed.

Further, as illustrated in FIGS. 3A and 3B, the downstream merging mechanism 35 is disposed between the Z scanner 33 and the laser beam scanning section 4, and combines the distance measurement light emitted from the distance measurement light emission section 5A. , and the laser beam passing through the Z scanner 33 are made coaxial. Therefore, since the distance measuring light is made coaxial in the optical path upstream of the laser beam scanning section 4, the distance measuring light can be scanned by operating the laser beam scanning section 4.

At the same time, the distance measuring light is also made coaxial in the optical path downstream of the Z scanner 33. Therefore, measurement resolution using distance measuring light can be ensured without making the aperture of the Z scanner 33 excessively large.

Further, as illustrated in FIG. 3B, not only the distance measuring light emitted from the distance measuring light emitting section 5A but also the distance measuring light reflected by the workpiece W and received by the distance measuring light receiving section 5B is transmitted to the Z scanner 33. does not pass through. Therefore, the ranging light emitting section 5A and the ranging light receiving section 5B can be disposed close to each other, and it is possible to suppress the effects of distortion of the casing and the like caused by temperature changes. This is effective in ensuring the accuracy of distance measurement by the distance measurement unit 103.

Further, as illustrated in FIG. 3A, the guide light emitted from the guide light source 36 sequentially passes through the upstream merging mechanism 31, the Z scanner 33, the downstream merging mechanism 35, and the laser beam scanning unit 4. The light passes through and is irradiated onto the workpiece W.

Here, the upstream merging mechanism 31 is provided between the laser light output section 2 and the Z scanner 33, and is configured to combine the guide light emitted from the guide light source 36 and the laser light emitted from the laser light output section 2. and make them coaxial. Therefore, since the guide light and the laser light join in the optical path upstream of the Z scanner 33, the focal position of the guide light can be adjusted by operating the Z scanner 33. This makes it possible to improve the visibility of the guide light.

《Second embodiment》
First, a laser processing system S including a first embodiment of a laser processing apparatus L will be described. In the following description, the second embodiment will simply be referred to as the present embodiment, unless it is emphasized that the configuration is unique to the second embodiment. Furthermore, descriptions of configurations common to the first embodiment will be omitted as appropriate.

15A is a diagram corresponding to FIG. 3A illustrating a marker head 1' according to a second embodiment of the laser processing apparatus L, and FIG. 15B is a diagram corresponding to FIG. 3A illustrating a marker head 1' according to the second embodiment of the laser processing apparatus L. This is a diagram corresponding to FIG. 3B. Further, FIG. 16A is a diagram corresponding to FIG. 13A illustrating the reflectance of the laser beam entrance surface 351' according to the second embodiment, and FIG. 16B is a diagram corresponding to the reflectance of the laser beam exit surface 352' according to the second embodiment. FIG. 13B is a diagram corresponding to FIG. 13B illustrating the example of FIG. 17A is a diagram corresponding to FIG. 14A illustrating the optical path of the near-infrared laser beam and the guide light in the second embodiment, and FIG. 17B is a diagram corresponding to FIG. 14B illustrating the optical path of the distance measuring light in the second embodiment. It is a correspondence diagram.

The optical member 35a according to the second embodiment selectively transmits only the wavelength band of the distance measuring light, while selectively reflecting the respective wavelength bands of the near-infrared laser beam and the guide light. As a result, as illustrated in FIGS. 15A and 15B, in the downstream merging mechanism 35' according to the second embodiment, the optical path formed by the ranging light, the optical path formed by the guide light and the near-infrared laser light, are different from the first embodiment.

Specifically, the optical member 35a' according to the second embodiment has a reflectance corresponding to the wavelength band of the distance measuring light that is equal to that of the laser beam entrance surface 351' and the laser beam exit surface 352' according to the second embodiment. In both, it is set to substantially 0% (see Figures 16A and 16B). With this setting, the distance measuring light incident on the laser light emitting surface 352' passes through the laser light emitting surface 352'. The distance measuring light that has passed through the laser beam exit surface 352' passes through the inside of the optical member 35a while being refracted, and is emitted to the outside from the laser beam entrance surface 351' (see FIG. 17B).

On the other hand, the laser beam entrance surface 351' according to the second embodiment selectively reflects the wavelength band of the guide light and the near-infrared laser beam, as shown in FIG. 16A. On the other hand, the laser light emitting surface 352' according to the first embodiment transmits the wavelength band of the guide light and the near-infrared laser light, as shown in FIG. 16B.

With this setting, most of the guide light and near-infrared laser light that have entered the laser light entrance surface 351' will be reflected by the laser light entrance surface 351'. A small portion of the guide light and near-infrared laser light that entered the laser light entrance surface 351' is emitted to the outside from the laser light exit surface 352' without being reflected by the laser light entrance surface 351'. See Figure 17A).

Similarly to the optical member 35a according to the first embodiment, the optical member 35a' according to the second embodiment is capable of suppressing the propagation of distance measurement light (especially reflected light of the distance measurement light) to the guide light source 36. can. This makes it possible to make both the guide light and the distance measurement light coaxial with the near-infrared laser beam, increase the amount of light received by the distance measurement light receiving section 5B, and suppress a decrease in measurement accuracy.

《Other embodiments》
In the embodiment, near-infrared laser light is used as the processing laser light (printing laser light), but the wavelength band thereof is not limited thereto. Further, the magnitude relationship among the wavelength band of the printing laser beam, the wavelength band of the guide light, and the wavelength band of the ranging light can be changed as appropriate.

FIG. 18 is a diagram comprehensively illustrating combinations of wavelengths that can be taken by the near-infrared laser beam, the guide light, and the ranging light. For example, the configuration shown in the top row of FIG. 18 exemplifies the wavelength settings in the first and second embodiments.

On the other hand, in Modification 1 in the second row from the top, for example, the wavelength of the laser beam for printing is changed to 532 nm or 355 nm, and the wavelengths of the guide light and distance measuring light are the same as in the first and second embodiments. This corresponds to when set to .

In addition, in Modification 2 in the third row from the top, for example, the wavelength band of the guide light is changed to the low wavelength side in the near-infrared region (for example, 750 nm or more and 950 nm or less), and the wavelength band of the printing laser light and distance measurement light is This corresponds to the case where is set similarly to the first and second embodiments.

In addition, in Modification 3 in the fourth row from the top, for example, the wavelength of the laser beam for printing is changed to 532 nm, the wavelength of the guide light is changed from the ultraviolet region to the blue visible light region (around 400 nm), and the distance measurement This corresponds to the case where the wavelength of light is set similarly to the first and second embodiments.

In addition, in Modification 4 in the fifth row from the top, for example, the wavelength of the laser beam for printing is changed to 532 nm or 355 nm, the wavelength of the guide light is changed to the near-infrared region (750 nm or more), and the wavelength of the distance measuring light is changed to 532 nm or 355 nm. This corresponds to the case where is set similarly to the first and second embodiments.

Further, in Modification 5 in the sixth row from the top, for example, the wavelength of the guide light is set in the same manner as in the first and second embodiments, the wavelength of the printing laser light is changed to 532 nm, and the wavelength of the distance measuring light is changed to 532 nm. This corresponds to the case where the wavelength is changed from the ultraviolet region to the blue visible light region (around 400 nm).

Further, in each combination shown in FIG. 18, the reflectance of the distance measuring light in the optical member is set to substantially 100%, and the reflectance of the guide light and printing laser light is set to substantially 0%. Alternatively, by selecting whether to set the reflectance of the ranging light on the optical member to substantially 0% and set the reflectance of the guide light and the printing laser light to substantially 100%, A configuration corresponding to the first and second embodiments described above can be realized.

1 Marker head 10 Housing 2 Laser light output section 3 Laser light guide section 31 Upstream side merging mechanism (guide light merging mechanism)
33 Z scanner (focus adjustment section)
35 Downstream side merging mechanism (ranging light merging mechanism)
35a Optical member 351 Laser light incidence surface 352 Laser light emission surface 36 Guide light source (guide light emission section)
4 Laser beam scanning section 5 Distance measurement unit 5A Distance measurement light emission section 5B Distance measurement light reception section 100 Marker controller 103 Distance measurement section 110 Excitation light generation section S Laser processing system W Work (workpiece)

Claims (9)

an excitation light generation unit that generates excitation light;
a laser light output unit that generates laser light based on the excitation light generated by the excitation light generation unit and emits the laser light;
It has rotatable first and second mirrors, and irradiates the workpiece with the laser light emitted from the laser light output section via the first and second mirrors , and a laser beam scanning unit that performs two-dimensional scanning on the surface of the workpiece by adjusting the rotational attitude of the mirror;
A laser processing device comprising a casing in which at least the laser light output section and the laser light scanning section are provided,
a guide light emitting section provided inside the housing and emitting guide light for projecting a predetermined machining pattern onto the surface of the workpiece;
a guide light merging mechanism that is provided in the middle of the laser light path from the laser light output section to the laser light scanning section inside the housing, and that merges the guide light emitted from the guide light output section into the laser light path; ,
A distance measuring light provided inside the housing and scanned two-dimensionally by the laser beam scanning unit, the distance measuring light for measuring the distance from the laser processing device to the surface of the workpiece. A distance measurement light emitting part that emits the light,
An optical member is provided inside the housing between the guide light merging mechanism and the laser beam scanning unit in the laser optical path, and the optical member allows the distance measuring light to be emitted from the distance measuring light emitting unit. The distance measuring light is merged into the laser optical path between the guide light merging mechanism and the laser beam scanning section , and the surface of the workpiece is two-dimensionally scanned by the laser beam scanning section to scan the surface of the workpiece. a ranging light merging mechanism that reflects or transmits the ranging light that returns via the laser beam scanning unit after being reflected on the surface of the laser beam ;
The distance measuring light emitted from the distance measuring light emitting section provided inside the housing is two-dimensionally scanned and reflected on the surface of the workpiece, and then transmitted to the laser beam scanning section and the measuring light. a distance measurement light receiver that receives the distance measurement light returned via the distance light merging mechanism;
a distance measurement unit that measures the distance from the laser processing device to the surface of the workpiece based on the distance measurement light reception position in the distance measurement light reception unit ;
The optical member selectively reflects or transmits only the wavelength band of the distance measuring light among the respective wavelength bands of the laser beam, the guide light, and the distance measuring light, so that the distance measuring light is A laser processing device characterized by guiding distance measuring light to a light receiving section. The laser processing apparatus according to claim 1,
A laser processing device characterized in that the optical member is coated so as to selectively reflect or transmit only the wavelength band of the distance measuring light. The laser processing apparatus according to claim 1 or 2,
The laser processing apparatus is characterized in that the optical member selectively reflects only a wavelength band of the distance measuring light, while transmitting wavelength bands of each of the laser beam and the guide light. In the laser processing apparatus according to claim 3,
On the front and back of the optical member,
a laser light entrance surface on which the laser light and the guide light enter;
a laser beam exit surface through which the laser beam and the guide light incident from the laser beam entrance surface pass through the optical member and exit;
The laser light emitting surface selectively reflects only the wavelength band of the ranging light,
A laser processing apparatus characterized in that the laser beam entrance surface is configured to transmit a wavelength band of the distance measuring light. The laser processing apparatus according to claim 1 or 2,
The laser processing apparatus is characterized in that the optical member selectively transmits only the wavelength band of the distance measuring light, while selectively reflecting the wavelength bands of the laser beam and the guide light. The laser processing apparatus according to any one of claims 1 to 5,
a focus adjustment section provided inside the housing and adjusting the focal position of the laser light emitted from the laser light output section;
The laser processing apparatus is characterized in that the distance measuring light merging mechanism is disposed in the laser optical path between the focus adjustment section and the laser beam scanning section. The laser processing apparatus according to claim 6,
The laser processing apparatus is characterized in that the guide light merging mechanism is disposed in the laser light path between the laser light output section and the focus adjustment section. The laser processing apparatus according to any one of claims 1 to 7,
The wavelength bands of the ranging light and the guide light are both set in the visible light range,
A laser processing apparatus characterized in that the wavelength of the laser beam is longer than the wavelengths of the distance measuring light and the guide light. The laser processing apparatus according to claim 8,
The wavelength of the laser beam is set to 1064 nm, 532 nm or 355 nm,
The wavelength band of the ranging light is set to 680 nm or more and 695 nm or less,
A laser processing apparatus characterized in that a wavelength band of the guide light is set to 645 nm or more and 660 nm or less.

Images