Westinghouse Electric Corporation

Vincent A Toth

William H Kasner

Phillip J Hawkins

Richard A Miller

Gerald Joseph Bruck

Zoltan K Kun

David Leksell

Luciano C Scala

John M Zomp

Roger L Swensrud

Wei-Fang A Su

Daniel P Soroka

James F Roach

Lyn D Pleasance

Steve A Wutzke

Mariann C Stroster

A method for defining an array of light-emitting pixels in a thin film electroluminescent edge emitter structure includes the steps of moving the structure in proximity to a stationary first laser source as the first laser source is operated to generate a plurality of first laser pulses. The plurality of first laser pulses are focused into 'lines' of light energy that strike the structure at a plurality of spaced apart locations in succession to ablate a predetermined number of layers of the structure. This ablation process forms a plurality of spaced apart channels in the structure. The portions of the structure remaining between each pair of adjacent channels define an array of pixels in the structure. The structure having the pixels formed therein is moved in proximity to a second laser source. The second laser source is movable in a selected direction substantially perpendicular to the direction of movement of the structure. The second laser source provides a second laser beam that is focused to a 'point' of light energy which strikes the end portion of each pixel at an area inward of the pixel edge surface to ablate a predetermined number of layers at each pixel end portion. The movement of the second laser beam is controlled relative to the movement of the structure to correspondingly control the amount of material ablated inward of the edge surface of each pixel to remove the pixel edge surface and form a new pixel edge surface shaped to a preselected contour.

Process for defining an array of pixels in a thin film

A laser welding system is disclosed in which a high power laser produces the laser beam for delivery to a weld site. A transmitter is optically coupled to the laser and directs the laser beam to a spatially separated receiver. The receiver has an input alignable for receiving the directed laser beam and including optics for delivering the laser beam to the weld site. A pair of directable beam deflectors are employed for aligning the transmitter and the receiver. A pair of steering deflectors introduce the laser beam into the transmitter. A selectable mounting allows the laser to be secured at various orientations relative to the steering mirrors and the weld site. The transmitter and the receiver each have a detector positioned for receiving an alignment laser beam at a point which indicates alignment. The transmitter and the receiver include steppable drives for positioning their respective deflectors. The alignment laser is aligned at a starting block on the receiver detector and the transmitter detector. The steppable drives are each driven away from the starting block by an amount sufficient to eliminate backlash when the drives are reversed. Each steppable drive is then reversed and driven in one direction to bring the alignment laser beam back to the starting block and thereafter into the alignment position in a series of sequential alignment steps.

Laser beam alignment and transport system

A system which utilizes a source of ultraviolet radiation to mark a surface or to cure selectively a photosensitive paint applied to a surface. The source of UV light is either a laser or a broadband source and the light is controlled by an aperture and/or a stencil apparatus. The photosensitive paint is applied by a controlled technique as a protective or a decorative coating.

Technique for the application and cure of photosensitive paints

In one embodiment, a laser welding head is formed of a hollow tubular housing, and includes multiple focusing means for refocusing and realigning the laser beam if it is misaligned relative to the axis of the housing. In another embodiment, the housing is formed of a plurality of flexibly interconnected segments having at least one focusing means in each segment for realigning the beam and for directing the laser beam along interconnected linear paths.

Flexible laser welding head for sleeve-to-tube welding

A detector for aligning a laser beam has been provided. The detector includes an insulative substrate, and a thermally conductive planar face attached to the substrate. The face is divided into thermally isolated sectors, each sector having the same shape and area. A corresponding thermal sensitive device is provided for each sector. Each sector is in thermal contact with a corresponding one of the thermal sensitive devices, and each thermal sensitive device produces a response proportional to the amount of laser energy impinging thereon to thereby provide indication of the misalignment of the laser beam relative to the transport path.

Detector for aligning high power lasers

A controlled depth laser drilling system for a workpiece containing metallic conductors is provided having at least one laser beam (56 and/or 57 of FIG. 5) where a portion of the laser beam (44) will be reflected from the workpiece and back to a drilling depth monitoring means (43) containing optical means capable of reflecting a portion of the original and reflected laser beams into radiation detector means (46', 46' and/or 45', 45'), where the detector means are capable of converting the radiation received into a measurable electrical signals.

Controlled depth laser drilling system

A system is disclosed for aligning a high-power laser apparatus to transmit a high-power beam along an optimum beam path to an adjustable remote beam receiver and for aligning the beam receiver for optimum reception of the high-power beam. A low-power visible laser is directed along the path to be followed by the high-power laser and a viewer such as a video camera is used for rough alignment. A pellicle, a partially reflecting mirror, and three low-power beam detectors are used with the low-power laser to align the beam transmitter with the beam receiver. Alignment of the beam receiver with the beam transmitter is checked by a high-power laser beam alignment checking system. This alignment checking system employs an annular beam detector mounted near the beam transmitter and a second beam detector mounted near the beam receiver. A beam intensity reducer is used to reduce the intensity of the high-power beam for use in alignment since prolonged direct contact by a full-power beam with the detectors would damage the detectors. A method for aligning the laser beam transmitter and receiver is also described.

A method for welding a sleeve within a tube of a steam generator, the sleeve being in close contact with the tube. A welding head of a weld head apparatus is positioned within the tube at a predetermined weld site, a laser beam is directed to the welding head, the beam is focused with a focusing means, the focused laser beam is reflected with a welding mirror means into contact with a portion of the sleeve to be welded to the tube, the welding mirror means is maintained a predetermined focal distance from the inside surface of the sleeve, and the welding head is rotated to complete a weld fusion path about the inner periphery of the sleeve. Shielding gas is used to shield the weld site. A robotic arm positions the weld head apparatus within the steam generator. At each end of the sleeve, multiple discrete weld paths or a continuous helical multiple weld path are welded. The sleeve is preferably welded to the tube along the weld path with a fusion width at the interface between the sleeve and tube of at least 0.045 inches and the tube is penetrated to a depth of at least 0.25 inches. The laser delivers 500 to 700 watts to the weld area.

Laser welding of a sleeve within a tube

Apparatus is disclosed for aligning a laser beam used to perform laser machining operations. The aligning apparatus of this invention is used with laser machining apparatus comprising a laser for emitting a laser beam along a path and a laser lens assembly disposed within the path and movable along an axis for variably focusing the laser beam at a plurality of different focal spots corresponding to the plurality of laser machining operations. The alignment apparatus takes the form of an adjustable mirror, which is disposed to intercept the laser beam and to align at least a portion of the path with the axis of the laser lens assembly, whereby the lateral displacement of each of said plurality of focal spots from the axis is reduced as the laser focusing assembly is moved along its axis.

Beam alignment system for laser welding system

The direct electrical discharge excitation, pulsed or CW, of a laser gas medium consisting of CO.sub.2 :N.sub.2 :He present in the approximate ratio of 1:2:25 at a total gas pressure of between approximately 8 and 12 Torr and an operating temperature between approximately 125.degree. K. and 150.degree. K. supports 16 micron laser radiation on the 02.sup.0 0.fwdarw.01.sup.1 0 CO.sub.2 vibrational transition, and 14 micron laser radiation on the 10.sup.0 0.fwdarw.01.sup.1 0 CO.sub.2 vibrational transition.

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Penn Township, Westmoreland County, PA, United States of America

Vincent A Toth