A laser processing device includes: a laser light source emitting laser light; a converging optical system converging the laser light at an object to be processed; a reflective spatial light modulator modulating the laser light such that the laser light is caused to branch into 0th order light and ±nth order light (n is a natural number) including at least first processing light and second processing light, and the first processing light is converged at a first converging point and the second processing light is converged at a second converging point; and a light blocking part blocking light to be converged at an outside with respect to the first processing light and the second processing light of the 0th order light and the ±nth order light to be converged at the object.

A method for manufacturing a cutting tool having a rake face, a flank face, and an edge having a ridge line interconnecting the rake face and the flank face, wherein on the flank face there is a cutting edge region from the ridge line of the edge to a point A away therefrom on the side of the flank face by a distance X, the method comprising producing and processing the flank face with a laser, the producing and processing being producing and processing the cutting edge region along the ridge line of the edge with a first laser beam having a depth of focus equal to or deeper than a width of the cutting edge region when the distance X is the width of the cutting edge region, the distance X being 0.2 mm or more and 5 mm or less.

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 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 height position of a surface of a wafer can be detected accurately and stably without being affected by variation in a thin film formed on the surface of the wafer. An AF (autofocus) device irradiates the surface of the wafer W with an AF laser beam, detects reflection light thereof for each wavelength with a detection optical system. An AF signal processing unit outputs a displacement signal indicating displacement of the surface of the wafer to a control unit on the basis of a detection result of the detection optical system. Moreover, the AF device includes a focus optical system disposed in an irradiation optical path which is an optical path from the light source unit to a light converging lens. The focus optical system adjusts a light converging point of the AF laser beam in a wafer thickness direction.

A height position of a surface of a wafer can be detected accurately and stably without being affected by variation in a thin film formed on the surface of the wafer. An AF (autofocus) device irradiates the surface of the wafer W with an AF laser beam, detects reflection light thereof for each wavelength with a detection optical system. An AF signal processing unit outputs a displacement signal indicating displacement of the surface of the wafer to a control unit on the basis of a detection result of the detection optical system. Moreover, the AF device includes a focus optical system disposed in an irradiation optical path which is an optical path from the light source unit to a light converging lens. The focus optical system adjusts a light converging point of the AF laser beam in a wafer thickness direction.

A method and an apparatus for joining two workpieces by means of a processing beam by forming a weld seam along a lap joint, wherein a gap formed at the lap joint between the two workpieces is filled during welding. The processing beam performs a spatial oscillatory movement parallel and/or perpendicular to the joint during welding. The oscillation parameters of said oscillation, the feed rate, the power of the processing beam and the angle of incidence of the processing beam onto the surfaces of the workpieces are adjusted dynamically during the welding process such that the upper sheet is fused in line with demand and the melt flows from the upper sheet down to the lower sheet thus closing the gap. The gap height is measured permanently during welding and the process parameters are adjusted such that a reliable closing of the gap is made possible.

A method and an apparatus for joining two workpieces by means of a processing beam by forming a weld seam along a lap joint, wherein a gap formed at the lap joint between the two workpieces is filled during welding. The processing beam performs a spatial oscillatory movement parallel and/or perpendicular to the joint during welding. The oscillation parameters of said oscillation, the feed rate, the power of the processing beam and the angle of incidence of the processing beam onto the surfaces of the workpieces are adjusted dynamically during the welding process such that the upper sheet is fused in line with demand and the melt flows from the upper sheet down to the lower sheet thus closing the gap. The gap height is measured permanently during welding and the process parameters are adjusted such that a reliable closing of the gap is made possible.

Provided are a machining device and a machining method in which machining of higher precision can be performed with a simple configuration. The machining device has an irradiation head (16) and a controller; and the irradiation head (16) can be divided into a collimate optical system, a laser revolving unit (35), and a light collection optical system (37). The laser revolving unit (35) has a first prism (51), a second prism (52), a first rotation mechanism (53), and a second rotation mechanism (54). The controller controls the rotational speeds and the difference in phase angles of the first prism (51) and the second prism (52), on the basis of at least the relationship between a heat affected layer of a member to be machined and the revolving speed of the laser.

Provided are a machining device and a machining method in which machining of higher precision can be performed with a simple configuration. The machining device has an irradiation head (16) and a controller; and the irradiation head (16) can be divided into a collimate optical system, a laser revolving unit (35), and a light collection optical system (37). The laser revolving unit (35) has a first prism (51), a second prism (52), a first rotation mechanism (53), and a second rotation mechanism (54). The controller controls the rotational speeds and the difference in phase angles of the first prism (51) and the second prism (52), on the basis of at least the relationship between a heat affected layer of a member to be machined and the revolving speed of the laser.