JP5731833B2 - Laser processing equipment - Google Patents

Description

  The present invention relates to a laser processing apparatus, and more particularly to an improvement of a laser processing apparatus that processes a workpiece by irradiating a laser beam.

  The laser marking device is a laser processing device that processes a workpiece (work) by irradiating a laser beam, and prints characters, symbols, figures, etc. on the workpiece by scanning the irradiation position of the laser beam. be able to. Such a laser marking device has an emergency stop function for forcibly stopping the output of laser light based on an emergency stop signal in order to ensure safety. For example, the emergency stop signal is input from a control device such as a PLC (programmable logic controller) when, for example, an emergency stop button is pressed or when an intrusion of a human body into the monitoring area is detected (for example, Patent Document 1).

  In the conventional laser marking device, when an emergency stop signal is input, an emergency stop state in which the output of the laser beam is forcibly stopped is maintained, and this emergency stop state is maintained until the main power is turned off by human operation. The In other words, in order to cancel the emergency stop state, the main power supply must be turned off and then turned on again. It takes a long time to restart the device. It was. In particular, in the case of a laser marking device, there is a problem that it takes time to stabilize the laser temperature control.

  Therefore, it is conceivable to provide a release switch for releasing the emergency stop state and to operate the release switch so that the emergency stop state is released without turning off the main power. However, there has been a problem that it is necessary to avoid the emergency stop state being released even though the release switch malfunctions due to the influence of noise or the like and the release operation is not performed.

JP 11-309590 A

  The present invention has been made in view of the above circumstances, and a laser processing apparatus capable of suppressing an emergency stop state from being erroneously released while simplifying a release procedure for releasing the emergency stop state. The purpose is to provide. In particular, an object of the present invention is to provide a laser processing apparatus that can prevent an emergency stop state from being erroneously canceled even if noise is mixed in an output signal from a release switch. Moreover, it aims at providing the laser processing apparatus which improved the operativity of cancellation | release operation of an emergency stop state.

The laser processing apparatus according to the first aspect of the present invention shifts to a laser generator that generates laser light for processing a workpiece and an emergency stop state that prohibits the laser light from being emitted to the workpiece based on an emergency stop signal from the outside. An emergency stop control means for releasing the emergency stop state based on an emergency stop release signal for releasing the emergency stop state, a release switch for performing a release operation for the user to release the emergency stop state, , detected by a plurality of electrical contacts one of the release operation for one of the release switch, a release operation detecting means for outputting a plurality of release operation detection signal in response to the detection timing due to the plurality of electrical contacts, the releasing operation detection Stop release means for generating the emergency stop release signal based on the time difference between the output timings of the plurality of release operation detection signals output from the means; With configured.

  With such a configuration, the release operation for the release switch is detected by the release operation detection unit, and the emergency operation is performed based on the time difference between the output timings of the plurality of release operation detection signals output from the release operation detection unit according to the detection timing. The stopped state is released. For this reason, even if the release operation detection signal is erroneously output from the release operation detection means due to the influence of noise or the like, it is possible to suppress the emergency stop state from being released. Even if a plurality of release operation detection signals are erroneously output from the release operation detection means, the emergency stop state is not released if the time difference between the output timings of these release operation detection signals is sufficiently large. Accordingly, it is possible to prevent the emergency stop state from being erroneously canceled due to the influence of noise or the like even though the cancellation operation is not performed.

  The release operation refers to a rotation operation, a slide operation, a pressing operation, etc. for the release switch, and the release operation detecting means detects the same release operation for the same release switch and outputs a plurality of release operation detection signals. It is also possible to detect different release operations on the same release switch, or to detect release operations on different release switches.

  A laser processing apparatus according to a second aspect of the present invention includes, in addition to the above configuration, first comparison means for comparing a time difference between output timings of a plurality of release operation detection signals output from the release operation detection means with a first threshold value. The stop cancellation means is configured to generate the emergency stop cancellation signal when the time difference is equal to or smaller than a first threshold value.

The third laser machining apparatus according to the present invention, in addition to the above structure, the release operation detection means comprises two of said electrical contacts are opened and closed respectively by the primary the release operation.

  With such a configuration, the release operation detection signals are output from the two electrical contact circuits by the same release operation with respect to the same release switch. For this reason, since only a slight time difference occurs between the output timings of the two release operation detection signals, the first threshold can be set to a relatively short time. Therefore, it is possible to more reliably prevent the emergency stop state from being erroneously canceled due to the influence of noise or the like even though the canceling operation is not performed.

  Note that the same release operation means that a series of operations performed by the user without releasing his / her finger on the release switch is the same. In addition, when it is necessary to sequentially perform a plurality of operations on one or more switches in order to cancel the emergency stop state, the last operation that completes these operations is the cancellation operation referred to here. It corresponds to.

  In addition to the above configuration, the laser processing apparatus according to the fourth aspect of the present invention is configured such that one of the plurality of release operation detection signals is a positive logic signal and the other is a negative logic signal.

  With such a configuration, even if a plurality of release operation detection signals are both affected by noise, if the noise component mixed in each is the same, the emergency stop state can be erroneously released. Absent.

  A laser processing apparatus according to a fifth aspect of the present invention includes, in addition to the above configuration, second comparison means for comparing the duration of the release operation detection signal with a second threshold, wherein the stop release means has the first time difference as the first time difference. The emergency stop cancellation signal is generated when the threshold value is less than or equal to the threshold value and both the durations are equal to or greater than the second threshold value.

  With such a configuration, even when pulse-like noise is mixed into a plurality of release operation detection signals and the time difference is less than or equal to the first threshold value, both durations must be greater than or equal to the second threshold value. In this case, the emergency stop state is not released. For this reason, the emergency stop state is not erroneously canceled even when pulse noise is mixed almost simultaneously with a plurality of release operation detection signals.

  In addition to the above configuration, the laser processing apparatus according to the sixth aspect of the present invention is configured such that the emergency stop control means controls power supply to the laser generator. With such a configuration, the output of the laser beam can be stopped reliably.

  In the laser processing apparatus according to the present invention, the release operation with respect to the release switch is detected by the release operation detection unit, and based on the time difference between the output timings of the plurality of release operation detection signals output from the release operation detection unit according to the detection timing. The emergency stop state is released. For this reason, even if the release operation detection signal is erroneously output from the release operation detection means due to the influence of noise or the like, it is possible to suppress the emergency stop state from being released. Even if a plurality of release operation detection signals are erroneously output from the release operation detection means, the emergency stop state is not released if the time difference between the output timings of these release operation detection signals is sufficiently large. Accordingly, it is possible to prevent the emergency stop state from being erroneously canceled due to the influence of noise or the like even though the cancellation operation is not performed.

  In the laser processing apparatus according to the present invention, one of a plurality of release operation detection signals is a positive logic signal and the other is a negative logic signal, so that the same noise component is mixed into the plurality of release operation detection signals. However, the emergency stop state will not be canceled by mistake. Accordingly, it is possible to prevent the emergency stop state from being erroneously canceled due to the influence of noise or the like even though the cancellation operation is not performed.

  In the laser processing apparatus according to the present invention, the emergency stop state is canceled when the duration of the release operation detection signal is equal to or longer than the second threshold value. For this reason, the emergency stop state is not erroneously canceled even when pulse noise is mixed almost simultaneously with a plurality of release operation detection signals. Accordingly, it is possible to prevent the emergency stop state from being erroneously canceled due to the influence of noise or the like even though the cancellation operation is not performed.

  Furthermore, in the laser processing apparatus according to the present invention, the emergency stop state of the laser output can be canceled by operating the release switch, so that the release procedure can be simplified and the operability can be improved.

1 is a system diagram showing an example of a schematic configuration of a laser marking system 1 including a laser marker 20 according to an embodiment of the present invention. It is the block diagram which showed the detailed structure of the laser marker 20 of FIG. FIG. 3 is a block diagram illustrating a configuration example of a marker controller 22 in FIG. 2. It is the figure which showed the structural example of the laser output control part 224 in the marker controller 22 of FIG. FIG. 5 is a block diagram illustrating a configuration example of an SSR control unit 13 in the laser output control unit 224 of FIG. 4. It is explanatory drawing which showed typically the structural example of power supply SW32 for laser output of the marker controller 22 of FIG. 3, and the case where the contacts 111 and 121 are a interruption | blocking state is shown. It is the figure which showed the case where the contacts 111 and 121 changed to the conduction | electrical_connection state by rotating power supply SW32 for laser outputs of FIG. FIG. 4 is a diagram showing an example of an operation at the time of operation of the laser output power source SW32 of the marker controller 22 of FIG. 3, and outputs of the electrical contact circuits 11 and 12 are shown. 5 is a flowchart showing an example of the operation of the laser output control unit 224 in FIG. 4.

<Laser marking system 1>
FIG. 1 is a system diagram showing an example of a schematic configuration of a laser marking system 1 including a laser processing apparatus according to an embodiment of the present invention. A laser marker 20 is shown as an example of the laser processing apparatus. The laser marking system 1 includes a laser marker 20 that irradiates a laser beam L to process a workpiece W, and a terminal device 10 for editing the processing conditions. The laser marker 20 includes a marker head 21 that generates and scans the laser light L, and a marker controller 22 that controls the operation of the marker head 21.

  The terminal device 10 is a device for controlling the laser marker 20, and for example, a personal computer in which an application program for a laser marker is installed can be used. By using the terminal device 10, the user can create and edit processing setting data that defines the processing conditions of the laser marker 20.

  The marker controller 22 controls the operation of the marker head 21 based on the processing setting data received from the terminal device 10. Further, excitation light for laser oscillation is generated in the marker controller 22 and transmitted to the marker head 21 via the optical fiber 23.

  The marker head 21 generates laser light L based on the excitation light from the marker controller 22 and irradiates the workpiece W with it. At this time, by scanning the emission axis of the laser light L based on the control signal from the marker controller 22, symbols such as characters, symbols and figures can be printed on the workpiece W. In addition, an illumination light source and a camera (not shown) are built in the marker head 21, and a photographed image of the work W photographed by the camera is transferred to the terminal device 10 via the marker controller 22 and displayed on the display. The The user can check and adjust the processing position on the workpiece W by browsing the captured image.

  The marker controller 22 is provided with a terminal block 31 composed of a plurality of input / output terminals for connecting external devices such as a PLC and an emergency stop button, and a laser output power source SW (switch) 32. If the user operates the emergency stop button or the PLC detects an abnormality, an emergency stop signal for prohibiting the laser light L from being emitted to the workpiece W is input via the terminal block 31.

  When an emergency stop signal is input, the marker controller 22 enters an emergency stop state that prohibits the laser light L from being emitted toward the workpiece W. This emergency stop state is an interlock state in which the emission of the laser light L to the workpiece W cannot be resumed unless the user performs a predetermined release operation.

  The laser output power supply SW32 is a switch that switches between an on state in which power is supplied to the laser light L generator and an off state in which laser output is stopped. The emergency stop state occurs when an emergency stop signal is input when the laser output power source SW32 is on. In order to cancel this emergency stop state, the laser output power supply SW32 may be temporarily switched to the off state and then switched to the on state again.

<Laser marker 20>
FIG. 2 is a block diagram showing a detailed configuration of the laser marker 20 of FIG. 1, and shows an example of the internal configuration of the marker head 21 and the marker controller 22.

  The laser marker 20 can perform high-precision laser processing by irradiating the laser beam L through the telecentric lens 48. Further, the illumination light source 53 and the camera 56 for photographing the workpiece W are provided, and the optical axis of the illumination light source 53 and the photographing axis of the camera 56 are arranged so as to be coaxial with the emission axis of the laser light L. For this reason, a captured image with less distortion can be obtained via the telecentric lens 48.

  The illumination light source 53 generates illumination light having substantially the same wavelength as the laser light L, and the camera 56 images return light having substantially the same wavelength as the laser light. For this reason, since the workpiece | work W can be image | photographed using the light of the wavelength substantially the same as the laser beam L, a clear picked-up image is obtained. Further, by providing the camera shutter 55 on the photographing axis of the camera 56, the laser light L reflected by the work W is prevented from being incident on the camera 56 as return light and being damaged.

<Marker controller 22>
The marker controller 22 supplies electric power to the marker head 21 using a commercial power source, and generates excitation light for laser oscillation. This excitation light is transmitted to the marker head 21 via the optical fiber 23. Further, the marker controller 22 controls the marker head 21 based on the processing setting data transferred from the terminal device 10, and performs output control and scanning control of the laser light L.

<Marker head 21>
The marker head 21 includes a laser oscillator 41, a beam sampler 42, an oscillator shutter 43, a mixing mirror 44, a Z scanner 45, a polarization beam splitter 46, an XY scanner 47, a telecentric lens 48, a power monitor 51, a guide light source 52, and an illumination light source 53. , A half mirror 54, a camera shutter 55, and a camera 56.

The laser oscillator 41 is a laser generator that absorbs excitation light and generates laser light L including a laser beam, and includes a laser medium, a resonator, a Q switch, and the like. Here, it is assumed that the laser oscillator 41 is a solid-state laser oscillator that pulsates, for example, an SHG type laser oscillator. The SHG type laser oscillator uses a YVO ₄ (yttrium vanadate) crystal doped with Nd (neodymium) as a laser medium, and outputs green light having a wavelength of 532 nm using the second harmonic. Laser light having a wavelength of 808 nm is used as excitation light for exciting the laser medium. The laser light L generated by the laser oscillator 41 is applied to the workpiece W via the beam sampler 42, the mixing mirror 44, the Z scanner 45, the polarization beam splitter 46, the XY scanner 47, and the telecentric lens 48 in order.

  The beam sampler 42 is an optical splitter that branches a certain proportion of the laser light L output from the laser oscillator 41 as a sampling beam. For example, by utilizing the surface reflection of the transparent substrate, about 3% of the total amount of the incident laser light L is dispersed and incident on the power monitor 51 as a sampling beam. The power monitor 51 is a light intensity detection means for detecting the output power of the laser oscillator 41, and is composed of, for example, a thermal element such as a thermopile, and the detection result is used for output control of the laser oscillator 41.

  The oscillator shutter 43 is a leakage prevention blocking means for blocking the laser light L emission path so that the laser light L can be opened and closed, and is disposed upstream of the polarization beam splitter 46. Here, an oscillator shutter 43 is provided between the beam sampler 42 and the mixing mirror 44, and the emission path of the laser light L is blocked based on the output control signal of the laser light L except when the laser light L is irradiated. Yes. For this reason, when the work 56 is photographed by the camera 56, the emission path of the laser light L is blocked by the oscillation shutter 43.

  The mixing mirror 44 is an optical mixing optical splitter that substantially matches the emission axis of the guide light with the emission axis of the laser light L, transmits the laser light L from the laser oscillator 41, and reflects the guide light from the guide light source 52. Both are sent to the Z scanner 45. The guide light source 52 is a light source device that generates guide light for displaying a processing position on the workpiece W, and includes a light emitting element such as an LD (laser diode). The symbol pattern to be printed can be visually recognized as an afterimage of the irradiation spot by the lighting control of the guide light and the high-speed scanning of the emission axis of the guide light.

  The Z scanner 45 is a beam diameter control means for adjusting the beam diameter of the laser light L. The Z scanner 45 is composed of two lenses arranged on the optical axis of the laser light L, and changes the relative distance between these lenses. For example, the beam diameter 2 mmφ of the laser beam L can be expanded to a maximum of 8 mmφ. By increasing the spot diameter of the laser light, defocus control that reduces the energy density in the spot can be performed.

  The polarization beam splitter 46 is disposed on the upstream side of the XY scanner 47 on the emission path of the laser light L, and transmits the laser light L from the Z scanner 45, while the light receiving axis of the camera 56 is used as the laser light L. This is an optical splitter for a camera that substantially coincides with the output axis of the camera. That is, of the reflected light from the workpiece W, the return light that enters the telecentric lens 48 and goes back through the emission path of the laser light L is reflected by the polarization beam splitter 46, thereby being separated from the emission axis of the laser light L, The light enters the camera 56. The polarization beam splitter 46 reflects the illumination light incident through the half mirror 54 toward the XY scanner 47, and makes the emission axis of the illumination light substantially coincide with the emission axis of the laser light L. For example, when the P-polarized laser light L is generated by the laser oscillator 41, the laser light L is allowed to pass by using the polarization beam splitter 46 that selectively transmits the P-polarized component and reflects the S-polarized component. On the other hand, the return light and the irradiation light including the S-polarized component can be reflected, respectively.

  The XY scanner 47 is a scanning device for two-dimensionally scanning the emission axis of the laser light L, and includes an optical system such as a scanning mirror that reflects the laser light L and a drive unit that rotates the scanning mirror. The scanning mirror is called a galvanometer mirror, and is arranged on the emission path of the laser light L. The XY scanner 47 rotates the scanning mirror based on the position control signal from the marker controller 22.

  The telecentric lens 48 is an emission optical system that emits the laser beam L toward the workpiece W, and is disposed downstream of the XY scanner 47 in the emission path of the laser beam L, that is, on the workpiece W side. The telecentric lens 48 is composed of a plurality of optical lenses and a cover glass, and includes an object side telecentric optical system in which the angle of view on the workpiece W side is approximately 0 °. That is, the telecentric lens 48 emits the laser light L toward the workpiece W so that the principal ray of the laser light is substantially parallel to the lens optical axis regardless of the incident angle of the laser light L.

  The illumination light source 53 is a light source device that generates illumination light for illuminating the workpiece W, and includes a light emitting element such as an LED (light emitting diode). The illumination light source 53 generates illumination light including at least the same wavelength as the laser light L and emits the illumination light to the half mirror 54.

  The half mirror 54 is an optical splitter for illumination that is disposed on the light receiving path of the camera 56 and transmits the return light from the polarization beam splitter 46, while making the emission axis of the illumination light substantially coincide with the light receiving axis of the camera 56. That is, the return light from the polarization beam splitter 46 is transmitted and incident on the camera 56, while the illumination light from the illumination light source 53 is reflected toward the polarization beam splitter.

  The camera shutter 55 is a camera protection blocking means for blocking the light receiving path of the camera 56 so that it can be opened and closed, and preventing the return light from entering the camera 56 when the laser beam L is irradiated. It arrange | positions rather than the upstream. Here, a camera shutter 55 is provided between the half mirror 54 and the camera 56 and is opened and closed based on the output control signal of the laser light L, and the light receiving path of the camera 56 is cut off at least during the irradiation period of the laser light L. ing. For this reason, if the timing of laser irradiation is different from the timing of camera shooting, it is possible to prevent the camera 56 from being damaged by the return light of the laser light L.

  The camera 56 is an imaging unit that captures the workpiece W and generates a captured image. The camera 56 captures an image based on an imaging control signal from the marker controller 22, and outputs the obtained captured image to the marker controller 22. Here, it is assumed that the camera 56 receives substantially the same wavelength as the laser light and generates a captured image.

<Marker controller 22>
FIG. 3 is a block diagram showing a configuration example of the marker controller 22 of FIG. The marker controller 22 includes a terminal block 31, a laser output power source SW 32, a power source SW 33, a main power source 220, an SSR 221, an excitation light generator 222, a main controller 223, and a laser output controller 224.

  The main power supply 220 is a power supply device that supplies power to the marker head 21, the excitation light generation unit 222, the main control unit 223, and the laser output control unit 224 using a commercial power supply, and operates a predetermined power supply SW33. Thus, the operation state is switched between the on state and the off state. In the off state of the main power supply 220, the power supply to the marker head 21, the excitation light generation unit 222, the main control unit 223, and the laser output control unit 224 is interrupted, and the power supply SW33 cannot be operated unless the power supply SW33 is operated.

  An SSR (Solid State Relay) 221 is used to cut off the power supply to the excitation light generation unit 222 based on a relay control signal from the laser output control unit 224, or to release the cut-off state and restart the power supply. It is a relay circuit and consists of a semiconductor element.

  The excitation light generator 222 is an excitation light source device that generates excitation light for laser oscillation, and is supplied with power from the main power supply 220 via the SSR 221. The main control unit 223 controls the excitation light generation unit 222 and the marker head 21 based on the processing setting data transferred from the terminal device 10, and performs output control and scanning control of the laser light L.

  The laser output control unit 224 detects an operation on the laser output power source SW32 and generates a relay control signal for switching the SSR 221 to an on state or an off state. When the laser output power SW 32 is in an on state, the laser output control unit 224 receives the predetermined emergency stop signal from the PLC or the emergency stop button via the terminal block 31, and the excitation light generation unit 222. A relay control signal for shutting off the power supply to is generated, and an emergency stop state is entered. Thereby, the emission of the laser beam L to the workpiece W is prohibited. In the emergency stop state, the laser oscillation is stopped, the Q switch is controlled, or the oscillator shutter 43 is closed, so that the emission of the laser light L to the workpiece W is prohibited.

  On the other hand, in the emergency stop state based on the emergency stop signal, after the laser output power SW 32 is switched from the on state to the off state (manual switching or automatic switching may be performed), the off state is switched to the on state. When switched, a relay control signal for canceling the emergency stop state and restarting the output of the laser light L is generated.

<Laser output control unit 224>
FIG. 4 is a diagram illustrating a configuration example of the laser output control unit 224 in the marker controller 22 of FIG. The laser output control unit 224 includes two electrical contact circuits 11 and 12 that are turned on almost simultaneously by operating the laser output power source SW32, two SSR control units 13, and one logic circuit 14. Is done.

The electrical contact circuit 11 is a release operation detection circuit that detects a release operation with respect to the laser output power source SW32 and outputs a predetermined release operation detection signal to the SSR control unit 13, and includes an electrical contact 111, a resistance element R ₁₁ , an LPF 112, and the like. It consists of a Schmitt trigger 113.

  The electrical contact 111 is, for example, a mechanical contact composed of two terminal electrodes. When these terminal electrodes come into contact with each other by operating the laser output power source SW32, the terminal electrodes are brought into conduction and turned on. The electrical contact circuit 11 generates a release operation detection signal as a negative logic state signal in which the voltage level becomes high in the off state.

Resistive element R ₁₁ is an electrical contact 111 a device for pulling up, one terminal electrode of the electrical contact 111 is grounded, it is supplied with a DC power source through a resistor R ₁₁ to the other terminal electrode Yes. LPF (low pass filter) 112 is a circuit device for removing high frequency components, a resistor element _{R 12} and a capacitor _{C 1.}

  The Schmitt trigger 113 is a circuit element for removing signal fluctuation, and its output state changes with hysteresis with respect to input changes. The output of the electrical contact 111 is input to the Schmitt trigger 113 via the LPF 112.

The electrical contact circuit 12 is a contact circuit that generates a release operation detection signal as a positive logic state signal in which the voltage level is low in the off state, and is configured in the same manner as the electrical contact circuit 11. Specifically, it is constituted by an electrical contact 121, a resistance element R ₂₁ for pulling down the electrical contact 121, an LPF 122 and a Schmitt trigger 123.

One terminal electrode of the electrical contact 121 is grounded via a resistor R _21, the other terminal electrode is supplied with a DC power supply. The output of the electrical contact 121 through the LPF122 consisting resistive element _{R 22} and a capacitor _{C 2,} is input to the Schmitt trigger 123.

  The electrical contact circuits 11 and 12 are connected to the same laser output power source SW32 and are opened and closed by the same release operation. That is, the electrical contacts 111 and 121 are turned on almost simultaneously by operating the laser output power source SW32.

  The SSR control unit 13 generates a relay control signal for stopping the output of the laser light L based on the emergency stop signal input from the outside of the SSR control unit 13, and shifts to the emergency stop state. On the other hand, in the emergency stop state based on the emergency stop signal, it is detected based on the release operation detection signal from the electrical contact circuits 11 and 12 that the electrical contact circuits 11 and 12 are turned on almost simultaneously, and the laser beam A relay control signal for resuming the output of L is generated, and the emergency stop state is released.

  In this example, two SSR control units 13 having the same configuration are provided in order to prevent accidental release of the emergency stop state when a problem occurs in the SSR control unit 13. The output of each SSR control unit 13 is input to the logic circuit 14. The logic circuit 14 is a circuit element that outputs a logical product of two inputs. The logic circuit 14 turns on the SSR 221 only when a relay control signal having substantially the same voltage level is input from the two SSR control units 13, and outputs the laser. Release the stopped state.

<SSR control unit 13>
FIG. 5 is a block diagram showing a configuration example of the SSR control unit 13 in the laser output control unit 224 of FIG. The SSR control unit 13 includes an emergency stop control unit 131, a time difference comparison unit 132, a duration comparison unit 133, and a stop release unit 134.

  Based on the emergency stop signal, the emergency stop control unit 131 shifts to an emergency stop state in which the output of the laser light L is forcibly stopped, and generates a relay control signal for cutting off the power supply to the excitation light generation unit 222 To do. On the other hand, based on the emergency stop cancellation signal from the stop cancellation unit 134, a relay control signal for canceling the emergency stop state and restarting the output of the laser light L is generated. The emergency stop control unit 131 includes a predetermined latch circuit.

  When the time difference comparison unit 132 receives the release operation detection signal from the Schmitt triggers 113 and 123, the time difference comparison unit 132 compares the time difference between the output start timings of the two release operation detection signals with a predetermined determination threshold Th1, and cancels the comparison result. Output to the unit 134.

  When the release operation detection signal is received from the Schmitt triggers 113 and 123, the duration comparison unit 133 compares the duration of the release operation detection signal with a predetermined determination threshold Th2 for each release operation detection signal, and the comparison result Is output to the stop cancellation unit 134.

  The stop cancellation unit 134 generates a predetermined emergency stop cancellation signal based on the comparison result of the time difference comparison unit 132 and the comparison result of the duration comparison unit 133 and outputs the signal to the emergency stop control unit 131. Specifically, when the time difference between the output start timings of the two release operation detection signals is equal to or less than the determination threshold Th1, and the duration of each release operation detection signal is equal to or greater than the determination threshold Th2, the emergency stop release signal Is generated. That is, the emergency stop state is canceled only when the two electrical contact circuits 11 and 12 are turned on almost simultaneously and the on state continues for the determination threshold Th2 or more.

<Laser output power SW32>
FIG. 6 is an explanatory diagram schematically showing a configuration example of the laser output power supply SW32 of the marker controller 22 of FIG. 3, and shows a case where both the electrical contacts 111 and 121 are in a cut-off state. The laser output power SW 32 is a rotary switch, and includes a key portion 61 and a cylinder portion 62 into which the key portion 41 is inserted in a removable manner. By turning the key part 61 with the key part 61 inserted into the cylinder part 62, the cylinder part 62 can be rotated.

  The cylinder part 62 is a movable part common to the electrical contacts 111 and 121, and protrusions 62a and 62b are provided in association with these electrical contacts. The protrusions 62a and 62b are both made of a flat insulating member, and are provided at different positions in the rotation axis direction of the cylinder part 62.

  The electrical contact 111 is turned off when the protrusion 62 a is inserted between the terminal electrodes of the electrical contact 111. The electrical contact 121 is turned off when the protruding portion 62 b is inserted between the terminal electrodes of the electrical contact 121. That is, by rotating the cylinder part 62 to a predetermined position, the electrical contacts 111 and 121 can be shifted to the off state almost simultaneously.

  FIG. 7 is a diagram showing a case where the electrical contacts 111 and 121 are both brought into a conducting state by operating the laser output power source SW32 of FIG. When the protruding portion 62a is extracted from between the terminal electrodes, the electrical contact 111 is brought into conduction between the terminal electrodes and is turned on. When the protruding portion 62b is extracted from between the terminal electrodes, the electrical contact 121 conducts between the terminal electrodes and is turned on.

  That is, by rotating the cylinder part 62 by a predetermined amount from a position where the electrical contacts 111 and 121 are turned off, the electrical contacts 111 and 121 can be shifted to the on state almost simultaneously.

<Output of electrical contact circuit>
FIG. 8 is a diagram showing an example of the operation at the time of operation of the laser output power supply SW32 of the marker controller 22 of FIG. 3, and the outputs of the electrical contact circuits 11 and 12 are shown. The electrical contact circuit 11 is a contact circuit that generates a negative logic release operation detection signal whose output level becomes high in the off state. By operating the laser output power supply SW32, the output level is in the low state. Migrate to In this example, the electrical contact circuit “contact 1” is turned on at time t ₁ by the operation of the laser output power source SW 32.

On the other hand, the electrical contact circuit 12 is a contact circuit that generates a positive logic release operation detection signal in which the output level becomes a low level in the off state. By operating the laser output power supply SW32, the output level is high. Transition to the on state. In this example, the electrical contact circuit "Contact 2" by operating the laser output power supply SW32, is shifted to a time t ₂ to the ON state.

The time difference comparison unit 132 of the SSR control unit 13 compares the time difference T1 = t ₂ −t ₁ with the determination threshold value Th1 when the two electrical contact circuits are turned on, and if the time difference T1 is equal to or less than the determination threshold value Th1. Thus, it is determined that these electrical contact circuits are turned on almost simultaneously. For example, if the time difference T1 from when one electrical contact circuit is turned on until the other electrical contact circuit is turned on is about 100 ms or less, it is considered that the state has shifted to the ON state at the same time.

The duration comparison unit 133 compares the duration T2 in the on state with the determination threshold Th2 when the electrical contact circuit shifts to the on state. The stop canceling unit 134 cancels the emergency stop state only when the two electrical contact circuits are turned on almost simultaneously and the duration T2 is equal to or greater than the determination threshold Th2. Specifically, if the duration T2 = t ₃ −t ₂ is longer than the determination threshold Th2, the laser output stop state is released. For example, the laser output stop state is canceled if the ON state is maintained for the duration T2 = 1 s after the two electrical contact circuits are simultaneously turned ON.

  Steps S101 to S109 in FIG. 9 are flowcharts showing an example of the operation of the laser output control unit 224 in FIG. If an emergency stop signal is input from the outside, the SSR control unit 13 generates a relay control signal for switching the SSR 221 to the off state. Thereby, the laser marker 20 transfers to an emergency stop state (step S101). Next, if there is a user's release operation, the electrical contact circuits 11 and 12 output a release operation detection signal according to the detection timing (steps S102 and S103).

  At this time, the SSR control unit 13 compares the time difference between the output timings of the release operation detection signals output from the electrical contact circuits 11 and 12 with a threshold Th1 for time difference determination, and sets the duration of each release operation detection signal. It is compared with a threshold value Th2 for determining the duration (step S104).

  Then, based on these comparison results, the SSR control unit 13 cancels the emergency stop for canceling the emergency stop state if the time difference is equal to or less than the determination threshold Th1 and the duration is equal to or greater than the determination threshold Th2. A signal is generated (steps S105 and S106). On the other hand, when the time difference exceeds the determination threshold Th1 or the duration is less than the determination threshold Th2, the emergency stop state is not canceled and the emergency stop cancellation signal is not generated (steps S105 and S109).

  Next, the laser output control unit 224 determines whether or not the emergency stop state should be canceled based on the emergency stop cancellation signal generated in each SSR control unit 13 (step S107). When canceling the emergency stop state, a relay control signal for switching the SSR 221 to the on state is generated, and the emergency stop state is canceled (step S108). On the other hand, when the emergency stop state is not canceled, the SSR 221 is kept off (step S109).

  According to the present embodiment, the release operation for the laser output power source SW32 is detected by the two electrical contact circuits 11 and 12, and the time difference between the detection start times by the electrical contact circuits 11 and 12 is equal to or less than the determination threshold Th1. In such a case, the emergency stop state is released. For this reason, even if a release operation detection signal is erroneously output from one of the electrical contact circuits 11 and 12 due to the influence of noise or the like, the emergency stop state is not released. Even if the release operation detection signals are erroneously output from both the electrical contact circuits 11 and 12, the emergency stop state is released if the time difference between the output start timings of these release operation detection signals is larger than the determination threshold Th1. It will never be done.

  Further, the release operation detection signals are output from the two electrical contact circuits 11 and 12 by the same release operation for the same laser output power source SW32. For this reason, since only a slight time difference occurs between the output start timings of the two release operation detection signals, the determination threshold Th1 can be set to a relatively short time.

  In addition, since one of the two release operation detection signals is a positive logic signal and the other is a negative logic signal, even if both of the two release operation detection signals are affected by noise, If the noise components mixed in are the same, the emergency stop state is not canceled by mistake. Further, even when pulse-like noise is mixed into the two release operation detection signals and the time difference between them is equal to or less than the determination threshold Th1, if the duration T2 is not equal to or greater than the determination threshold Th2, the emergency The stopped state is not released. For this reason, the emergency stop state is not erroneously canceled even when pulse noise is mixed almost simultaneously with the two release operation detection signals.

  In the present embodiment, the example in which the two electrical contact circuits 11 and 12 both detect the same release operation with respect to one laser output power supply SW32 has been described, but the present invention has such a configuration. It is not limited to. For example, the configuration may be such that each electrical contact circuit detects a release operation for two different release SWs.

  Further, in the present embodiment, the example in which the release operation detecting means for detecting the release operation for the release SW is composed of an electrical contact circuit has been described. However, in the present invention, the configuration of the release operation detecting means is limited to the electrical contact circuit. It is not something. For example, the release operation for the release SW may be detected by a contactless circuit using a photo interrupter.

  In the present embodiment, an example in which the electrical contacts 111 and 121 of the electrical contact circuits 11 and 12 are mechanical contacts including two terminal electrodes has been described. However, the configuration of the electrical contacts is limited to this. It is not a thing. For example, the present invention can be applied to a device using a capacitance-type contact that detects a change in capacitance and turns on or off.

  Further, in the present embodiment, the example in which the electrical contact circuits 11 and 121 are turned on when the electrical contacts 111 and 121 are in a conductive state is described. The configuration may be such that the electrical contact circuits 11 and 12 are turned off.

  Further, in the present embodiment, the example in the case of interrupting the power supply to the excitation light generation unit 222 at the time of emergency stop based on the emergency stop signal has been described. However, the configuration for prohibiting the emission of the laser light L to the workpiece W is described. It is not limited to this. For example, a configuration may be adopted in which the Q switch of the laser oscillator 41 or the oscillator shutter 43 is controlled to prevent the laser light L from being emitted to the workpiece W.

  In the present embodiment, an example in which the laser marker 20 is an SHG type laser marking apparatus has been described. However, the laser processing apparatus according to the present invention is not limited to this. For example, the present invention can be applied to a fiber laser type marking apparatus. The fiber laser type marking device is a laser marker using a fiber doped with Yb (ytterbium) as an amplifier.

1 Laser marking system 10 PC
20 Laser marker 21 Marker head 211 Laser oscillator 212 Power monitor 213 Guide light source 214 Z scanner 215 XY scanner 216 Telecentric lens 217 Illumination light source unit 218 Camera shutter 219 Camera 22 Marker controller 220 Main power supply 221 Terminal block 222 Release SW
223 Power SW
224 SSR
225 Laser output power source 226 Excitation light generation unit 227 Control unit 228 Interlock and release circuit 23 Optical fiber 31 Beam sampler 32 Mixing mirror 33 PBS (polarization beam splitter)
34 Optical splitter for illumination 35 Shutter L for oscillator Laser beam W for processing W Workpiece

Claims (6)

A laser generator that generates laser light for workpiece processing;
After transitioning to an emergency stop state that prohibits the laser beam from being emitted to the workpiece based on an emergency stop signal from the outside, the emergency stop state is canceled based on an emergency stop release signal for releasing the emergency stop state. Emergency stop control means to
A release switch for performing a release operation for the user to release the emergency stop state;
One of the release operation for one of the release switch is detected by the plurality of electrical contacts, a release operation detecting means for outputting a plurality of release operation detection signal in response to the detection timing of each said electrical contact,
A laser processing apparatus comprising: a stop release unit that generates the emergency stop release signal based on a time difference between output timings of a plurality of release operation detection signals output from the release operation detection unit. A first comparison unit that compares a time difference between output timings of the plurality of release operation detection signals output from the release operation detection unit with a first threshold;
The laser processing apparatus according to claim 1, wherein the stop cancellation unit generates the emergency stop cancellation signal when the time difference is equal to or less than a first threshold value. The release operation detecting means, the laser machining apparatus according to claim 1 or 2, characterized in that it has two of said electrical contacts are opened and closed respectively by the primary the release operation.   4. The laser processing apparatus according to claim 1, wherein one of the plurality of release operation detection signals is a positive logic signal and the other is a negative logic signal. A second comparison means for comparing the duration of the release operation detection signal with a second threshold;
The said stop cancellation | release means produces | generates the said emergency stop cancellation | release signal, when the said time difference is below a 1st threshold value and the said duration is both above a 2nd threshold value. The laser processing apparatus in any one of.   The laser processing apparatus according to claim 1, wherein the emergency stop control unit controls power supply to the laser generator.

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