Abstract: Methods and systems are provided for using optical interferometry in the context of material modification processes such as surgical laser or welding applications. An imaging optical source that produces imaging light. A feedback controller controls at least one processing parameter of the material modification process based on an interferometry output generated using the imaging light. A method of processing interferograms is provided based on homodyne filtering. A method of generating a record of a material modification process using an interferometry output is provided.

Abstract: A laser irradiation device comprises a laser oscillator, a laser irradiation head that performs laser processing by directing the laser beam onto the region to be processed; and a transmission mechanism that gets the laser beam through emitted from the laser oscillator to the laser irradiation head. The laser irradiation head comprises: a laser beam adjustment unit that adjusts the laser light to create a laser beam; a protective glass window arranged in an emission region that emits the laser beam; a reflection mechanism that gets the laser beam through and reflects visible light; a wavelength-dependent optical screening mechanism that cuts off light of a wavelength region other than visible light from the light that is reflected by the reflection mechanism; an image adjustment lens unit that adjusts an image comprising visible light that is input from the wavelength-dependent optical screening mechanism; an image pickup camera that inputs an image; and an image processing mechanism that processes the image.

Abstract: A thin beam laser crystallization apparatus for selectively melting a film deposited on a substrate is disclosed having a laser source producing a pulsed laser output beam, the source having an oscillator comprising a convex reflector and a piano output coupler; and an optical arrangement focusing the beam in a first axis and spatially expanding the beam in a second axis to produce a line beam for interaction with the film.

Abstract: Provided are: a table on which a workpiece is placed, a laser oscillator emitting a laser beam; a light-guide optical system deflecting the beam emitted from the oscillator; a cylindrical extensible bellows surrounding an optical path of the beam after the light-guide optical system deflects the beam; a bend mirror moving in an axial direction of the bellows while extending/contracting the bellows and deflecting the beam having passed through the bellows toward the table; a machining head irradiating the workpiece with the beam deflected by the mirror; an abnormality detector including a beam-sensor light-emitting unit emitting a beam advancing parallel with an axis of the bellows and a beam-sensor light-receiving unit measuring the amount of received light of the beam; and a control device bringing down the laser oscillator when the amount of received light of the beam in the beam-sensor light-receiving unit falls below a first threshold.

Abstract: A method of manufacturing three-dimensional objects by laser sintering is provided, the object is formed by solidifying powder material layer by layer at locations in each layer corresponding to the object by means of laser radiation, wherein an IR-radiation image in an applied powder layer is detected, characterized in that defects and/or geometrical irregularities in the applied powder layer are determined on the basis of the IR-radiation image.

Abstract: According to example embodiments, a laser optical system includes a laser generator, at least one scan module, an objective lens, a relay lens, a review optical system, and a control device. The laser generator is configured to generate a laser beam. The at least one scan module is configured to reflect the laser beam generated by the laser generator and to direct the laser beam in different directions. The objective lens is configured to focus the laser beam on a substrate. The relay lens is configured to guide the laser beam scanned by the at least one scan module to within an incident range of the objective lens. The review optical system is configured to monitor, in real time, repair of the substrate using the laser beam. The control device is configured to control the at least one scan module.

Abstract: A device for accurately positioning laser scribed lines in a thin top layer of material with respect to lines already scribed in lower layers for the purpose of making solar panels. An alignment detector system is attached to and displaced from an optics unit that generates laser beams by a distance such that the detector measures the position of scribed lines in the lower layers in the area of the panel that will be scribed at a subsequent time. A motion and control system moves the panel such that the detector follows the path of one or more of the lines scribed in one of the lower layers and measures the position of the lines. The system accepts data from the alignment detector and uses the data to correct the relative position of the optics unit.

Abstract: Methods and systems for precisely removing selected layers of materials from a multi-layer work piece using laser ablation are disclosed. Precise removal of one or more selected layers of materials of a work piece may be performed by irradiating at least one location on a multi-layer work piece with a laser beam, ablating material at the at least one location, detecting one or more characteristics of the material ablated at the at least one location and analyzing the one or more characteristics to identify a change in at least one of the one or more characteristics that indicates a change in the type of material being ablated. Related systems are also described.

Abstract: An optical element for installation in a laser processing machine has a surface that is optically unused and/or not subject to a laser beam during operation of the laser processing machine when the optical element is installed in the laser processing machine, and a transponder disposed in a region on or near the surface and containing readable information relating to the optical element.

Abstract: A glass substrate laser cutting device according to the invention includes: a working table that has a plurality of vacuum absorbing grooves; a laser cutter; a pressure sensor that measures a pressure sensor when suctioning the glass substrate in a vacuum state; a calculation processing unit that compares the vacuum pressure measured by the pressure sensor with a predetermined threshold pressure and determines whether the glass substrate is broken; a laser cutter that includes a leaser head moving along the cutting direction of the glass substrate and emitting a laser beam; and an optical sensor that is attached to the laser head so as to move together and is disposed at a point in front of the laser beam emitted to the outside so as to detect the breakage of the glass substrate.

Abstract: Certain example embodiments of this invention relate to apparatuses for sealing the tips of pump-out tubes of vacuum insulating glass (VIG) units, and/or associated methods. In certain example embodiments, a laser source used in sealing the pump-out tube is thermally insulated from the VIG unit and emits a laser beam through one or more windows in an oven towards a mirror located therein. The mirror is located so as to redirect the laser beam onto the pump-out tube to thereby seal it. For instance, a substantially horizontal laser beam emitted from a laser source located outside the oven enters into the oven through one or more windows and is reflected by a mirror towards the pump-out tube to be sealed. The repositioning of the laser source advantageously can change its effective focal length and/or the location of the laser beam, e.g., because of the fixed location of the mirror.

Abstract: This robot system includes a robot, a laser emitting portion moved by the robot, emitting a laser beam to a target workpiece, and a control portion controlling the laser emitting portion to emit the laser beam on the basis of information regarding an arbitrarily-shaped work locus and movement information of the laser emitting portion.

Abstract: The present invention relates to a laser material processing system for processing a workpiece by means of a laser beam, comprising an optical system having at least one optical component for focusing the laser beam to form a focal point on the workpiece or in a defined position relative to the workpiece, at least one inertial sensor for detecting a transitional and/or rotational acceleration of the at least one optical component of the optical system and/or the workpiece, and a processing unit connected to the at least one inertial sensor for determining a relative transitional and/or rotational acceleration between the focal point and the workpiece.

Abstract: A method of processing an optical element includes providing the optical element. A surface region of the optical element includes one or more pre-cursors. The method also includes raster scanning a laser beam across the optical element. The laser beam comprises a plurality of laser pulses, each of the laser pulses being characterized by a pulse length less than 1 ns. The method further includes exposing the one or more pre-cursors to the laser beam and observing a light emission event from one of the one or more pre-cursors.

Abstract: The present invention generally relates to an optical system that is able to reliably deliver a uniform amount of energy across an anneal region contained on a surface of a substrate. The optical system is adapted to deliver, or project, a uniform amount of energy having a desired two-dimensional shape on a desired region on the surface of the substrate. An energy source for the optical system is typically a plurality of lasers, which are combined to form the energy field.

Abstract: A method of monitoring a welding process, comprising detecting a selected portion of a light spectrum of plasma plume of a fusion welding process with a photo detector, processing the detected portion of the spectrum, comparing the detected portion of the spectrum with an expected spectra to determine whether a weld is acceptable, providing a signal to a welder control, and adjusting the weld process based on the signal.

Abstract: A system for processing a multi-device panel, comprising a substrate having front and rear surfaces, a first array of device regions located on the front surface and a second array of device regions on the rear surface, by vector direct-write laser ablation, comprising a first processing station comprising a pair of opposedly-mounted processing heads, each processing head comprising a laser beam delivery apparatus comprising a laser beam scanner and a lens unit, and a distance measurement device, mounting device for mounting the panel between the processing heads of the first processing station such that the relative position of the panel and the first processing station can be adjusted so that the processing heads are brought into alignment with selected front-surface and rear-surface device regions to be processed, wherein each processing head is operable to make an estimate of the distance between the lens unit and the surface of the device region to be processed using the distance measurement device, cont

Abstract: A boroscope includes a working head having first and second ends. A first optical fibre extends through the boroscope to a position between the first and second ends. A second optical fibre extends through the boroscope to the second end of the working head. A laser optical fibre extends through the boroscope. At least one lens is arranged between the first end and the second end of the working head and a mirror is gimballed to the second end of the working head. The laser optical fibre directs laser light transmitted through the laser optical fibre onto the lens and then onto the mirror. A first LED is arranged at a position between the first end and the second end of the working head and a second LED is arranged at the second end of the working head and an actuator devices adjust the position of the mirror.

Abstract: A method for measuring the amount of material removed from a target in pulsed laser ablation is provided. The method includes generating a laser beam with a laser generator for ablating the target; driving the laser generator with a delay generator; acquiring the acoustic signal generated when the target is being ablated by the laser beam and generating an electrical signal accordingly with a microphone; amplifying the electrical signal generated by the microphone with a pre-amplifier; displaying an acoustic waveform indicating the intensity of the acoustic signal generated when the target is being ablated by the laser beam with a digital oscilloscope connected to the delay generator and the pre-amplifier; and deducing the amount of material removed from the target in the pulsed laser ablation according to the acoustic waveform in real time. An apparatus for performing the method is also provided.

Abstract: A laser scanning device includes a laser output unit, a scanner, a light splitting unit, an imaging compensation unit, a detection unit, and a control unit. A scanning focusing unit included in the scanner focuses a laser beam emitted by the laser output unit to scan an object. A visible light beam received by the canning focusing unit is reflected by the light splitting unit and is incident into the imaging compensation unit. Next, the detection unit receives the visible light beam passing through the imaging compensation unit, and outputs a detection signal. The control unit adjusts the detection signal according to the wavelength of the visible light beam, the wavelength of the laser beam, the scanning focusing unit, and the imaging compensation unit. Therefore, the laser scanning device may compensate the aberration and the dispersion caused when the visible light beam passes through the scanning focusing unit.

Abstract: The present invention relates to a method and apparatus for inspecting the quality of laser welding by monitoring the size of a metal molten pool (i.e., weld metal) during a laser welding process. The present invention provides a method and apparatus for inspecting the quality of laser welding, in which a new type laser welding quality inspection system is implemented in which one sensor signal and one filtered electrical signal of the plasma light can be used to perform a correct welding quality inspection through the development of a filtering method of an electrical signal of the plasma light, thereby facilitating a laser welding quality management and making possible its example application to a vehicle body laser welding process.

Abstract: A process control apparatus controls a focus position of a laser beam, while a laser processing mechanism converges the laser beam into a predetermined focus position and performs a laser processing on a workpiece. The process control apparatus includes: a calculator that, based on the magnitude of an output of the laser beam that changes during the laser processing, calculates a change amount of a positional deviation of the focus position in an optical axis direction that changes during the laser processing at a laser beam radiation position; and a control unit that, based on the change amount of the positional deviation that has been calculated by the calculator, controls the focus position of the laser beam during the laser processing so as to resolve the positional deviation of the focus position.

Abstract: A laser processing system quickly and flexibly modifies a processing beam to determine and implement an improved or optimum beam profile for a particular application (or a subset of the application). The system reduces the sensitivity of beam shaping subsystems to variations in the laser processing system, including those due to manufacturing tolerances, thermal drift, variations in component performance, and other sources of system variation. Certain embodiments also manipulate lower quality laser beams (higher M2 values) to provide acceptable shaped beam profiles.

Abstract: There is provided a hybrid ultraprecision machining device for manufacturing a micro-machined product from a workpiece, the machining device comprising: an electromagnetic-wave-machining means for roughly machining the workpiece; a precision-machining means for precisely machining the roughly machined workpiece, the precision-machining means being equipped with a replaceable cutting tool selected from the group consisting of a planar tool, a shaper tool, a fly-cutting tool, a diamond-turning tool and a micro-milling tool; a shape-measurement means for measuring a shape of the workpiece upon use of the electromagnetic-wave machining means and the precision-machining means; and a control means for controlling the electromagnetic-wave-machining means or the precision-machining means, based on information on the shape of the workpiece, the shape being measured by the shape-measuring means.

Abstract: A laser beam processing machine comprising a laser beam application means for applying a laser beam to a workpiece held on a chuck table, a processing-feed means, an indexing-feed means, a processing-feed amount detection means for detecting the amount of feed, an indexing-feed amount detection means, and a control means, wherein the condenser constituting the laser beam application means comprises an elliptic spot forming means for forming a focal spot into an elliptic shape and a focal spot turning means for turning the elliptic focal spot on an optical axis at the center thereof; and the control means comprises a storage means for storing the X, Y coordinate values of a processing line formed on the workpiece, obtains the X, Y coordinate values of the current position of a laser beam application position based on detection signals from the processing-feed amount detection means and the indexing-feed amount detection means, and controls the focal spot turning means to ensure that the long axis of the focal

Abstract: A system for thermal processing of a substrate includes a source of radiation, optics disposed between the source and the substrate to receive light from the source of radiation at the optics proximate end, and a housing holding the optics and having a void inside the housing isolated from light emitted from the source. A light detector is disposed within the void in the housing to detect light from the optics emitted into the housing and send a deterioration signal. The system further includes a power supply for the source of radiation, and a controller to control the power supply based on the deterioration signal from the light detector.

Abstract: A laser processing apparatus including a holding unit for holding a workpiece, a processing unit for applying a laser beam to the workpiece held by the holding unit, a surface displacement detecting unit for detecting a surface displacement of the workpiece, and a focal position adjusting unit for adjusting the position of a focusing lens provided in the processing unit according to the surface displacement detected. The surface displacement detecting unit includes a detecting light source capable of oscillating light having a plurality of wavelengths different from the wavelength of the laser beam and a wavelength selecting section configured to select one of the plurality of wavelengths as the wavelength of detecting light. The detecting light having the selected wavelength is focused by the focusing lens and applied to the workpiece.

Abstract: A laser processing apparatus 1 includes a processing light source 3 emitting processing light; an observation light emitting unit 4 emitting observation light; optical fibers 19 conducting light having a plurality of wavelengths generated at an electronic component 2; a detecting unit 5 detecting the light conducted by the optical fibers 19; and a control unit 31 controlling a light emitting state of the processing light emitting unit 3. The optical fibers 19 are categorized into four groups, and disposed so as to surround an optical fiber 18 conducting the processing light. The optical fibers 19 categorized into the four groups are capable of conducting the observation light to the electronic component 2 every group.

Abstract: A method and system for laser processing targets of different types on a workpiece are provided. The method includes setting a laser pulse width of one or more laser pulses to selectively provide one or more laser output pulses having one or more set pulse widths based on a first type of target to be processed. The method further includes setting a pulse shape of the one or more output pulses to selectively provide the one or more output pulses having the set pulse shape based on the types of targets to be processed. The method still further includes delivering the one or more output pulses having the one or more set pulse widths and the set pulse shape to at least one target of the first type. The method finally includes resetting the laser pulse width of one or more laser pulses to selectively provide one or more laser output pulses having one or more reset pulse widths based on a second type of target to be processed.

Abstract: Systems and methods for forming apertures in microfeature workpieces are disclosed herein. In one embodiment, a method includes directing a laser beam toward a microfeature workpiece to form an aperture and sensing the laser beam pass through the microfeature workpiece in real time. The method can further include determining a number of pulses of the laser beam and/or an elapsed time to form the aperture and controlling the laser beam based on the determined number of pulses and/or the determined elapsed time to form a second aperture in the microfeature workpiece.

Abstract: A system comprises a working laser beam, a sensing laser beam, first and second optical elements, an optical sensor, an aperture and a controller. The first optical element generates a coaxial beam from the working laser beam and the sensing laser beam. The second optical element focuses the coaxial beam onto a workpiece, such that the working laser beam machines the workpiece and the sensing laser beam reflects from the workpiece. The optical sensor senses an intensity of the reflected sensing beam. The aperture determines a focus position by translating along the reflected sensing beam, such that the reflected intensity is maximized. The controller determining a machining parameter of the working laser beam, based on the focus position.

Abstract: By irradiating laser light 20 obliquely onto a substrate 6, the laser soldering apparatus reduces the laser light passing through an insertion hole 61a in the substrate 6 and prevents damage to low-heat-resistance portions of a component 62 disposed on the rear surface side of the substrate 6. Moreover, the substrate 6 can be observed from a normal direction with a camera 23. Therefore, even if the insertion hole 61 for inserting a component lead or the like is provided in the substrate 6, the laser light does not leak out to the side of a component mounting surface 17 of the substrate 6.

Abstract: The invention relates to a method for machining a workpiece by means of a laser beam, wherein a laser beam is guided by a beam guiding device over the surface of the workpiece within a working window. The beam guiding device and the workpiece are arranged in such a way that they are movable relative to one another in a direction of displacement along a displacement section and that they can occupy a first and a second relative working position to one another. According to the invention, a point on the workpiece can be machined from the second relative working position, said point being located behind the point which is machined from the first relative working position when viewed in the direction of displacement.

Abstract: Methods and apparatus are disclosed for the preparation of microscopic samples using light pulses. Material volumes greater than 100 ?m3 are removed. The methods include inspecting an object with a scanning electron microscope (SEM) or a focused ion beam (FIB). The inspection includes recording an image of the object. The methods also includes delineating within the object a region to be investigated, and delineating a laser-machining path based on the image of the object so that a sample can be prepared out of the object. The methods further include using laser-machining along the delineated laser-machining path to remove a volume that is to be ablated, and inspecting the object with the scanning electron microscope (SEM) or a focused ion beam (FIB).

Abstract: A method for reducing stripe patterns comprising receiving scattered light signals from a backside surface of a laser annealed backside illuminated image sensor wafer, generating a backside surface image based upon the scattered light signals, determining a distance between an edge of a sensor array of the laser anneal backside illuminated image sensor wafer and an adjacent boundary of a laser beam and re-calibrating the laser beam if the distance is less than a predetermined value.

Abstract: A process for producing at least one photonic component (32, 33, 35, 39, 41), includes inserting the photonic component (32, 33, 35, 39, 41) into a surface layer (12) of a semiconductor wafer and/or within a semiconductor wafer, especially of a semiconductor chip (11, 31, 34, 38, 40) for the simpler and more cost-effective production with the most desired possible three-dimensional structures. At least one laser beam (22) is coupled into the material of the surface layer (12) and/or of the semiconductor wafer, in which the laser beam (22) is focused at a predetermined depth in the material. At least one property of the material and/or the material structure is changed in the area of focus (23, 36).

Abstract: A welding apparatus and a welding method are employed for laser narrow groove welding which performs welding scanning a laser beam in the welding direction while feeding a solid filler metal into a narrow groove. The welding apparatus includes a laser beam irradiation head having a mechanism periodically oscillating an irradiation point of the laser beam with a predetermined amplitude in the bottom of the groove, and a filler metal control device having a solid filler metal feeder feeding the solid filler metal to the molten pool formed in the bottom of the groove by the laser beam and adjusting the feeding position independent of a motion of the laser beam irradiation head so that the tip position of the solid filler metal detected is constantly positioned in the center of the groove.

Abstract: A method of dividing a workpiece includes: forming a pre-machining alteration region in the inside of a region in which no device is formed; detecting the position of the pre-machining alteration region through infrared imaging by imaging means, to thereby recognize a deviation between the pre-machining alteration region and a planned dividing line as machining position correction information; and forming a main machining alteration region by utilizing the machining position correction information, whereby the workpiece can be accurately divided along the planned dividing lines into individual devices.

Abstract: A workpiece processing machine, such as a laser cutting machine, includes a motion unit having an associated drive, a cutting head mounted on the motion unit and configured to deliver a cutting beam, and a suction duct or other form of beam interceptor coupled to the motion unit so that it moves therewith and an opening of the suction duct is positioned below the cutting head during a workpiece processing operation. The machine also includes a frame configured to support the motion unit and defining a movement area of the motion unit, the frame having a beam located generally centrally in the movement area.

Abstract: Systems and methods are provided for adjusting a laser beam applied to a workpiece in a processing operation. A laser processing system receives the laser beam that is associated with a beam quality property. The laser processing system adjusts the laser beam to change the beam quality property based on a characteristic of the workpiece, a characteristic of the processing operation, or a combination thereof. The adjusted laser beam can also be delivered to the workpiece.

Abstract: An apparatus and method for processing a plurality of semiconductor parts in a laser-based system adjusts a default recipe to account for work to be performed on at least one part of the plurality of parts. The work to be performed on a part is analyzed using the default recipe and a part-specific recipe including a modified parameter of the default recipe. The default or part-specific recipe is selected based on a desired processing result, and the selected recipe replaces the default recipe to perform the work using the laser-based system.

Abstract: A compliance monitoring system (40) for an intraoral appliance comprises a power source (460), a detector (410) for detecting when the intraoral appliance is positioned in the mouth for use, a recorder (430) configured to record measurement data, and a transponder (440) configured to communicate the measurement data. The monitoring system is adjustable based on a particular property of a patient or a group of patients.

Abstract: The present invention relates to a laser processing method and the like provided with a structure for enabling realization of both preferable processing of locations not easily reached by laser light and effective inhibition of damage caused to locations easily reached by laser light during laser processing. Radiation optics scan locations irradiated with laser light from a laser light source while radiating laser light onto a plurality of objects arranged on a stage and the periphery thereof from a direction perpendicular to the stage. On the stage reflecting members are respectively arranged adjacent to the plurality of objects. The reflecting members reflect laser light radiated from the radiation optics towards lateral surfaces of the objects. Since laser light reflected by the reflecting members is radiated onto the lateral surfaces of the objects, laser light also reaches the lateral surfaces of the objects not easily reached by laser light without having to increase the intensity of the laser light.

Abstract: The invention relates to a laser machining head (1) with an integrated sensor device for monitoring the focus position, wherein laser machining head (1) has a focusing lens (4) and a downstream protective glass (5) in order to focus a machining beam (9) that strikes focusing lens (4) as a parallel beam into a resultant focal point (11) of focusing lens (4) with downstream protective glass (5), in which focal point a workpiece (12) is arranged. A beam splitter (3), arranged upstream of focusing lens (4) in the beam path, is transmissive for a first portion of a laser beam (8) coupled into laser machining head (1), the machining beam (9), and is reflective for a second portion, a measurement beam (10).

Abstract: A welding or cutting device for welding or cutting electrically conductive work pieces has a pipe that accommodates feed lines, a nozzle for exit of a welding or cutting jet, such as a flame, for example, disposed at an end of the pipe, forming a device tip with its free end, and an inductive sensor device for measuring the distance between the device tip and the work piece. The sensor device has at least one magnetic coil, the windings of which run about a longitudinal device axis. The sensor device is a separate module, which is pushed onto the pipe and/or the nozzle, and releasably connected with the pipe and/or the nozzle.

Abstract: A laser processing system includes: a numerical control device (1) outputting a laser output signal and a digital signal; a converter (231) converting the laser output signal to an analog signal; a pulse signal generator (22) generating a pulse signal for controlling the analog signal; an auxiliary controller (7) generating a logic signal which forcedly controls transmission/stop of a laser beam; a logical operation unit (28, 29) outputting a result of the logical operation between the pulse signal and the logic signal; a switching device (27) generating a laser drive signal for alternately transmitting/stopping the laser output on the basis of the logical operation result; and a sensor (6) for measuring intensity of light radiated or reflected from a workpiece irradiated with a laser beam. The auxiliary controller (7) generates the logic signal in accordance with the intensity of the light measured by the sensor (6).

Abstract: A laser processing machine head, a laser processing machine head monitoring system, and a method of monitoring an optical element of a laser processing machine feature a light-transmissive optical element and an optical element holder defining a cavity in which the optical element is retained against rotation. A light source mounted to the holder directs a beam of light into the optical element through a peripheral surface of the optical element. A light receiver is responsive to light from the light source reflected through the optical element. Monitoring a signal from the light receiver allows a status of the optical element to be assessed.

Abstract: A device for material processing by laser radiation, including a source of laser radiation emitting pulsed laser radiation for interaction with the material, optics focusing the pulsed processing laser radiation to a center of interaction in the material, and a scanning unit shifting the positions of the center of interaction within the material. Each processing laser pulse interacting with the material in a zone surrounding the center of interaction assigned to the laser pulse so that material is separated in the zones of interaction. A control unit controls the scanning unit and the source of laser radiation such that a cut surface is produced in the material by sequential arrangement of zones of interaction. The control unit controls the source of laser radiation and the scanning unit such that adjacent centers of interaction are located at a spatial distance a ?10 ?m from each other.

Abstract: A laser beam having an annular spot shape with which a workpiece is irradiated is reflected on an upper surface and a lower surface of the workpiece. The reflected light having the annular spot shape which is reflected on the lower surface of the workpiece is intercepted by a pinhole mask, whereas the reflected light having the annular spot shape which is reflected on the upper surface of the workpiece is permitted to pass through the pinhole mask, and the intensity of light received is detected based on the latter reflected light. Therefore, the height position of the upper surface of a workpiece can be detected even where the workpiece is transmissive to visible rays. In this case, with regard to the reflected light having the annular spot shape which is reflected on the upper surface of the workpiece, the intensity of the light after diffusion by a laser beam diffusing unit is detected by a photodetector having a detecting surface with a predetermined area.

Abstract: A method for quality control of a weld bead made using a welding tool. The method collects, by an optical pyrometer having a high frequency acquisition sensor, at least one signal representative of the temperature of a melted portion of the weld bead, and includes a frequency phase for checking that the recurring frequencies are within an acceptable range of reference frequencies, to determine if the weld bead is defective.