A laser welding method is capable of easily restraining poor welding when spatters adhere to a protective glass of an optical system. The laser welding method includes a step of calculating a decrease-amount of the laser power before laser welding is performed by irradiating a welding portion of a workpiece with the laser beam having a predetermined power. The step of calculating the decrease-amount includes irradiating the welding portion with an inspecting laser beam having a power smaller than the predetermined power, receiving a return beam of the inspecting laser beam, measuring an intensity of the return beam, and comparing the intensity of the return beam with a standard intensity to calculate an amount of decrease in power of the inspecting laser beam at the welding portion.

A locking and fail-safe system can ensure proper installation of a lens assembly in a laser welding machine. The laser welding machine includes a laser head, a lens assembly, and an alignment tab operatively connected to the lens assembly. A device can be operatively positioned relative to the laser welding machine. The device can include a spring pin member with a movable slide pin. In a locked condition, the spring pin member can be positioned such that the slide pin is received in an aperture in the alignment tab, indicating that the lens assembly is properly installed and locking the lens assembly in place. A sensor can be used to determine whether the spring pin assembly is in a correct position, location, and/or orientation. The laser welding machine can be disabled if the spring pin member is not in a correct position, location, and/or orientation.

The machine learning apparatus includes: a state data observing unit which observes state data of the laser apparatus, including data output from a reflected light detecting unit for measuring a reflected light amount; an operation result acquiring unit which acquires a success/failure result indicating whether the machining has been started successfully by the laser beam output from a laser oscillator; a learning unit which learns light output command data by associating the light output command data with the state data of the laser apparatus and the success/failure result of the machining start; and a decision making unit which determines the light output command data by referring to the light output command data learned by the learning unit.

A laser processing system includes an irradiation device that irradiates a laser beam to a workpiece and includes a housing, a box positioned inside the housing and housing at least a part of a path of the laser beam, and at least one infrared sensor positioned inside the housing and around the box.

A laser machining device includes a first focus movement amount calculation section configured to calculate a focus movement amount based on comparison of a first measurement value obtained by averaging a plurality of measurement values measured by a returning light measurement unit within a first period and a second measurement value obtained by averaging a plurality of measurement values measured by the returning light measurement unit within a second period that is temporally later than the first period; and a focus position correction section configured to correct a focus position during laser machining based on the focus movement amount, and the first period is a period shortly after initiation of laser emission when the external optical system is not warmed up or is a period after correcting the focus position, and the second period is a period after passage of a certain time duration when the external optical system is warmed up.

A machine learning apparatus that learns laser machining condition data of a laser machining system includes: a state amount observation unit that observes a state amount of the laser machining system; an operation result acquisition unit that acquires a machined result of the laser machining system; a learning unit that receives an output from the state amount observation unit and an output from the operation result acquisition unit, and learns the laser machining condition data in association with the state amount and the machined result of the laser machining system; and a decision-making unit that outputs laser machining condition data by referring to the laser machining condition data learned by the learning unit.

Provided is a method for determining a laser irradiation state whereby the output of a laser can be acquired with high accuracy. This method for determining a laser irradiation state determines the irradiation state of a laser irradiated by a laser irradiation device and includes: an output stabilization time acquisition step for acquiring, as an output stabilization time, the time from the start of laser irradiation by the laser irradiation device until the stabilization of the output of the laser; an energy acquisition step for acquiring, after the output stabilization time or longer has elapsed from the start of the laser irradiation by the laser irradiation device, the energy of the laser irradiated by the laser irradiation device in a pre-set prescribed period; a conversion step for converting the acquired energy to the output of the laser irradiated by the laser irradiation device; and a state determination step for determining the irradiation state of the laser on the basis of the converted output of the laser.

The present disclosure includes a laser welding method in which a joint surface between a plurality of workpiece members is welded by radiating laser beam LB, and a locus of laser beam LB is controlled so as to perform wobbling scanning Sw by a combination of scanning motion Sa moving along first direction x parallel to the joint surface and swing motion Sb including first swing component Bx along first direction x and second swing component By along second direction y perpendicular to first direction x, the method including a defect determination step of determining occurrence of a welding defect; and an output control step of increasing or decreasing an output of laser beam LB when laser beam LB is radiated again toward the welding defect in a case where the welding defect occurs.

A device is provided for setting a focus position (z) of a laser beam in a laser machining system. The device comprises a computing unit configured to calculate a time-dependent value z.sub.t of the focus position (z), wherein the computing unit calculates the time-dependent value z.sub.t of the focus position (z) based on a first parameter and a second parameter, wherein the first parameter indicates a magnitude A of a laser-power dependent focus shift per power unit and the second parameter indicates a time constant τ of a change in focus position due to a thermal lens by a factor of 1/e, and a control unit configured to use a mechanism for setting the focus position (z) to set the focus position (z) of the laser beam based on the time-dependent value z.sub.t of the focus position (z).

A laser lift-off integrated apparatus includes a laser light source configured to perform laser lift-off on a wafer to undergo lift-off, a lift-off chamber configured to bear the wafer to undergo lift-off, a heater configured to provide temperature required by the wafer to undergo lift-off during a lift-off process, a profile measuring device configured to acquire surface profile information of the wafer to undergo lift-off, and a movable device configured to, according to the surface profile information acquired by the profile measuring device, adjust a height of the wafer to undergo lift-off such that a focus of the laser light source is at a position where the wafer to undergo lift-off is to undergo lift-off.