Abstract: A method and system of aligning color filter array are disclosed. Other embodiments are disclosed herein.

Abstract: A method of measuring an overlay includes generating an original signal using first and second overlay measurement keys that are spaced apart from each other, generating a first spectrum signal by performing Fourier transform of the original signal, generating a second spectrum signal by filtering the first spectrum signal, and generating a corrected signal by performing inverse Fourier transform of the second spectrum signal.

Abstract: A target space ratio of a monitor pattern on a substrate for inspection is determined to be different from a ratio of 1:1. A range of space ratios in a library is determined to include the target space ratio and not include a space ratio of 1:1. The monitor pattern is formed on a film to be processed by performing predetermined processes on the substrate for inspection. Sizes of the monitor pattern are measured. The sizes of the monitor pattern are converted into sizes of a pattern of the film to be processed having a space ratio of 1:1, and processing conditions of the predetermined processes are compensated for based on the sizes of the converted pattern of the film to be processed. After that, the predetermined processes are performed on a wafer under the compensated conditions to form a pattern having a space ratio of 1:1 on the film to be processed.

Abstract: Embodiments related to the alignment of a lens with an image sensor in an optical device are disclosed. For example, one disclosed embodiment comprises an optical device including a printed circuit board, and an image sensor package mounted on the printed circuit board, wherein the image sensor package includes an image sensor. The optical system further comprises a lens holder including a lens, and one or more alignment features arranged on the lens holder. The one or more alignment features are configured to contact the image sensor package to mechanically align the lens holder with the image sensor package.

Abstract: A test system for a multi-mode fiber comprises a launching device that is configured to generate optical pulses and has a rest position. A centering system is operable to move the launching device in a circular motion having a center corresponding to the rest position and a diameter corresponding to a core diameter of the multi-mode fiber. The centering system is further operable to adjust a position of the multi-mode fiber relative to the launching device while the launching device is moving in the circle until an optical power coupled from the launching device into the multi-mode fiber is below a threshold. The centering system optically centers the launching device with the multi-mode fiber by fixing the position of the multi-mode fiber responsive to the optical power coupled from the launching device into the multi-mode fiber being below the threshold and returning the launching device to the rest position.

Abstract: A method for determining an overlay offset may include, but is not limited to: obtaining a first anti-symmetric differential signal (?S1) associated with a first scatterometry cell; obtaining a second anti-symmetric differential signal (?S2) associated with a second scatterometry cell and computing an overlay offset from the first anti-symmetric differential (?S1) signal associated with the first scatterometry cell and the second anti-symmetric differential signal (?S2) associated with the second scatterometry cell.

Abstract: Within area where of four heads installed on a wafer stage, heads included in the first head group and the second head group to which three heads each belong that include one head different from each other face the corresponding areas on a scale plate, the wafer stage is driven based on positional information which is obtained using the first head group, as well as obtain the displacement (displacement of position, rotation, and scaling) between the first and second reference coordinate systems corresponding to the first and second head groups using the positional information obtained using the first and second head groups. By using the results and correcting measurement results obtained using the second head group, the displacement between the first and second reference coordinate systems is calibrated, which allows the measurement errors that come with the displacement between areas on scale plates where each of the four heads face.

Abstract: A beam deflection device including an aluminum disc containing a plurality of lasers, each laser projecting a laser beam substantially along one of the ‘X’, ‘Y’, and ‘Z’ axes of a structural beam to which the device is attached. Wiring is attached to each of the plurality of lasers to provide power and transmit data. Passageways are provided in the solid disc to route the wiring to the exterior. A suction cup on a surface of the device allows it to be attached to the beam by pressing the device against a flat surface area of the beam.

Abstract: A position detection apparatus includes an illumination optical system for illuminating a first diffraction grating having periods in each of a first direction and a second direction different from the first direction, and a second diffraction grating having a period different from the period in the second direction of the first diffraction grating in the second direction, at an oblique incidence, and a detection optical system for detecting diffracted light from the first diffraction grating and the second diffraction grating, wherein a relative position of the first diffraction grating and the second diffraction grating is detected based on the detected diffracted light, and wherein the illumination optical system includes a plurality of light intensity distributions in the first direction except for on an optical axis of the detection optical system, in a pupil plane thereof.

Abstract: For providing a die bonder, a bonding head device and a collet position adjusting method for enabling an automatic correction (adjustment) of errors, including height and inclination thereof, when exchanging a collet, with a simple structure thereof, in the bonding head device, having a holder 41h for guiding a vacuum for suction in an inside thereof, a shank 41s and a collet 41c, detachably attached at a tip of the holder, for adjusting the position of the collet after exchange of the collet, a reverse-side surface of that collet is photographed, before exchanging it, by a reverse-side surface photographing camera 42, which is disposed below the bonding head device, and after the exchange of the collet, the reverse-side surface of that collet exchanged, and then correction is made on positions of the collets, so that pictures photographed before/after the exchange thereof come to be coincident with.

Abstract: To provide a sighting device for use in a security sensor system, in which device enables an operator, assigned to conduct a sighting work, to look into the sighting device from a proper direction. The sighting device includes an eyepiece lens provided with a microlens, an objective lens provided with a first marker encompassed within the field of view of the eyepiece lens, and a reflecting mirror disposed on an optical path between the eyepiece lens and the objective lens. The first marker is comprised of a circular contour line or a polygonal contour line and is so set that when a viewing axis offsets from a tolerance, the first marker is viewed with a part thereof dropped out having been offset from the field of view of the microlens.

Abstract: Various embodiments of machine vision systems, methods, and devices are disclosed for providing passive alignment of an optical component to an electrical device. One embodiment is a method for passively aligning an optical subassembly to an electrical subassembly. One such method comprises: a machine vision system positioning an optical subassembly relative to an electrical subassembly; the machine vision system capturing an image of the optical subassembly; the machine vision system processing the image to identify an alignment member formed on the optical subassembly; and the machine vision system determining a first position of the optical axis of the optical subassembly based on a second position of the alignment member.

Abstract: A geodetic target 1 for use in geodesy comprises an orienting device 10 with a bearing direction P, a first inclinometer 20 with a first axis of inclination 20A, a reflector 30 reflecting incident measurement beams S, an imaging optics 40 that focuses the incident measurement beams S, a matrix sensor 50, whose receiving surface 51 is situated in an image plane of the imaging optics 40, and an interface 60, which is connected to the first inclinometer 20 and the matrix sensor 50. The spatial arrangement and orientation of the optical axis and/or axis of symmetry 30A of the reflector 30 relative to the bearing direction P of the orienting device 10 is predetermined here. The first axis of inclination 20A makes an angle ? other than zero with an optical axis 40A of the imaging optics 40. The optical axis 40A of the imaging optics 40 coincides with an optical axis 30A and/or axis of symmetry of the reflector 30 or is parallel to it or make an angle with it.

Abstract: An arrangement for providing passive alignment of optical components on a common substrate uses a set of reference cavities, where each optical device is positioned within a separate reference cavity. The reference cavities are formed to have a predetermined depth, with perimeters slightly larger than the footprint of their associated optical components. The reference cavity includes at least one right-angle corner that is used as a registration corner against which a right-angle corner of an associated optical component is positioned. The placement of each optical component in its own reference cavity allows for passive optical alignment to be achieved by placing each component against its predefined registration corner.

Abstract: The invention provides a structure for critical dimension and overlay measurement including a measuring unit, a first measurement pattern for measuring overlay and a second measurement pattern for measuring linewidth, line density and/or line semi-density. The first target pattern includes an outer bar structure disposed on a first layer and an inner bar structure disposed on a second layer; the outer bar structure and/or the inner bar structure has a same shared pattern structure with the second target pattern. The pattern structure includes four bars with the same shape positioned orthogonally and closely to each other, and at least two orthogonally positioned bars include N equally spaced rectangular lines of the same width, wherein, N is an odd number; the N rectangular lines include one central rectangular line and N?1 auxiliary rectangular lines.

Abstract: Precision approach path indicator (PAPI) measurement systems and methods are described herein. One system includes a number of light sensor modules, wherein each light sensor module is configured to determine an intensity of a beam of light from a PAPI unit, a memory, and a processor configured to execute executable instructions stored in the memory to determine a transition angle of the beam of light from the PAPI unit, an elevation angle of the beam of light with respect to horizontal, and a width of a transition region of the beam of light, based, at least in part, on the intensity of the beam of light determined by each light sensor module.

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets and small targets which are for measuring overlay. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

Abstract: A method of monitoring combustion properties in an interior of a boiler of the type having walls comprising a plurality of parallel steam tubes separated by a metal membrane. First and second penetrations are provided in the metal membrane between adjacent tubes on opposite sides of the boiler. A beam of light is projected through a pitch optic comprising a pitch collimating lens and a pitch relay lens, both residing outside the boiler interior. The pitch relay lens projects the beam through a penetration into the boiler interior. The beam of light is received with a catch optic substantially identical to the pitch optic residing outside the boiler interior. The strength of the collimated received beam of light is determined. At least one of the pitch collimating lens and the catch collimating lens may then be aligned to maximize the strength of the collimated received beam.

Abstract: A method and system align a laser diode on a first substrate to a waveguide on a second substrate. The first substrate includes an edge and a first surface adjoining the edge. The laser diode has an emission exit on the edge. The second substrate includes a back side and a side edge. The waveguide has a waveguide input on the back side and directs light along the side edge. A first alignment mark set on the first substrate is aligned to a second alignment mark set on the second substrate. The first alignment mark set corresponds to the emission exit, is formed on the first surface and is visible from the edge. The second alignment mark set corresponds to the waveguide input, is formed on the side edge, and is visible from the back side. The first substrate's edge is affixed to the second substrate's back side.

Abstract: The invention comprises a process for pre-aligning a lens with an optical system, the process comprising: providing a lens and an optical system having an optical axis, wherein the lens is apt to be aligned with the optical system to form on an image plane an image of a source object, the image having top, bottom, left and right edges; coarsely positioning the lens with respect to the optical system; and in a plane normal to the optical axis of the optical system, correcting the position of the lens until the values of four Combination Modulation Transfer Functions (C-MTF) are in predetermined ranges, the C-MTF being calculated at four coarse measurement locations situated close to the edges of the image along two coarse positioning axes crossing the center of the image, each for a combination pattern comprising a combination of a Sagittal pattern and a Tangential pattern.

Abstract: A segmented mask includes a set of cell structures, wherein each cell structure includes a set of features having an unresolvable segmentation pitch along a first direction, wherein the unresolvable segmentation pitch along the first direction is smaller than the illumination of the lithography printing tool, wherein the plurality of cell structures have a pitch along a second direction perpendicular to the first direction, wherein the unresolvable segmentation pitch is suitable for generating a printed pattern for shifting the best focus position of the lithography tool by a selected amount to achieve a selected level of focus sensitivity.

Abstract: In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum.

Abstract: In a method of aligning a substrate, a first alignment mark and a second alignment mark in a first shot region on the substrate may be sequentially identified. The substrate may be primarily aligned using identified any one of the first alignment mark and the second alignment mark. A used alignment mark and an unused alignment mark during the primary alignment process of the first alignment mark and the second alignment mark in a second shot region on the substrate may be sequentially identified. The substrate may be secondarily aligned using identified any one of the used alignment mark and the unused alignment mark during the primary alignment process. Thus, a time for identifying the alignment mark may be reduced.

Abstract: An apparatus and method to determine overlay of a target on a substrate (6) by measuring, in the pupil plane (40) of a high numerical aperture len (L1), an angle-resolved spectrum as a result of radiation being reflected off the substrate. The overlay is determined from the anti-symmetric component of the spectrum, which is formed by subtracting the measured spectrum and a mirror image of the measured spectrum. The measured spectrum may contain only zeroth order reflected radiation from the target.

Abstract: In the present invention, a number of times the brightness changes detected at the same position while a substrate conveys are added up in the conveying direction, thereby obtaining a plurality of edge count data, and then, a plurality of positions of long sides of patterns parallel to the conveying direction is identified based on the plurality of edge count data exceeding a predetermined threshold value, middle point positions of a plurality of proximity pairs are calculated, and a middle point position close to the target position preset in the imaging device is selected from the plurality of middle point positions of the proximity pairs, an amount of position displacement between the selected middle point position and the target position of imaging device is calculated, and the photomask in the direction substantially perpendicular to the conveying direction so that the amount of position displacement is a predetermined value.

Abstract: An optical assembly is provided for use with a laser alignment system that has a laser emitter and at least one photosensitive target. The optical assembly includes a right angle prism disposed for receiving an input beam produced by the laser emitter and first and second 90° pentaprisms disposed receiving the output from the right angle prism. The first and second 90° pentaprisms are oriented to produce first and second reflected beams that are parallel to one another. The optical assembly further includes first and second beam diverters disposed and oriented to receive the reflected beams from the first and second 90° pentaprisms and to produce first and second output beams that are mutually perpendicular. The first and second 90° pentaprisms may be see-through pentaprisms to produce a third output beam that is colinear or parallel with the input beam and perpendicular to the first and second output beams.

Abstract: For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.

Abstract: Disclosed is a method for appointing an orientation flat, in which when there are a plurality of orientation flats with the same length, any one from among the orientation flats of the same length can be certainly appointed as a reference orientation flat. In the disclosed method, three orientation flats at three positions are detected, respectively, through the rotation of a semiconductor wafer, the lengths of three circular arcs between the three orientation flats are obtained, respectively, and then an orientation flat at the right side of the longest circular arc from among the three circular arcs is appointed as a reference orientation flat. Accordingly, it is possible to certainly appoint a reference orientation flat even though there exist a plurality of circular arcs with the same length.

Abstract: A measurement system comprising an analog position sensitive device is provided that can measure the XY position of a plurality of light beams at very high resolution. In accordance with one exemplary associated method, a connector bearing one or more optical fibers is fixedly positioned before a position sensing detector so that light emanating from the ends of the optical fibers will strike the position sensing detector. A light beam is passed through at least one opening in the connector, such as a guide pin hole onto the detecting surface of the PSD to establish the position of the connector. Next, each optical fiber in the connector is individually illuminated sequentially so that the light emanating from the fiber falls on the position sensing detector. The locations of all of these light beams striking the PSD are compared to position of the light beam passed through the guide pins and/or to each other to determine if all the fibers are in the correct positions relative to the connector.

Abstract: An optical system for testing IR or UV sensors, comprises input optics, output optics having a reticule disposed on the associated optical axis, a radiation source which emits radiation in the visual spectral region and in the infrared or ultraviolet spectral regions, and a beam splitter for simultaneously visualizing an object scene illuminated by the radiation source with the reticule through the output optics into the eye of an observer. The input optics comprise a lens, the imaging properties of which in the visual spectral region are equal to the imaging properties in the infrared or ultraviolet spectral region, and the beam splitter is a dichroic beam splitter.

Abstract: Methods and systems for facilitating alignment of optical systems and optoelectronic systems are disclosed here. The methods and systems include passively detecting images, determining relative positions of components and aligning components. An imaging component can detect images and determine relative positions and repositioning instructions.

Abstract: A patterning device, including alignment targets having alignment features formed from a plurality of diffractive elements, each diffractive element including an absorber stack and a multi-layered reflector stack is provided. The diffractive elements are configured to enhance a pre-determined diffraction order used for pre-alignment and to diffract light in a pre-determined direction of a pre-alignment system when illuminated with light of a wavelength used for the pre-alignment. The diffractive elements may occupy at least half of an area of each alignment feature. The diffractive elements may be configured to enhance first or higher order diffractions, while substantially reducing zeroth diffraction orders and specular reflection when illuminated with a wavelength used for reticle prealignment. The dimensions of each diffractive element may be a function of a diffraction grating period of each alignment feature.

Abstract: A lithography apparatus includes a projection system configured to project a radiation beam onto a substrate, a detector configured to inspect the substrate, and a substrate table configured to support the substrate and move the substrate relative to the projection system and the detector. The detector is arranged to inspect a portion of the substrate while the substrate is moved and before the portion is exposed to the radiation beam.

Abstract: Example embodiments are directed to a maskless exposure device and an alignment method. The alignment method performs an overlay of each layer of a plurality of layers on a substrate using a virtual mask in a maskless exposure technique. The maskless exposure device and the alignment method use a virtual mask instead of a physical mask used in a conventional mask exposure, a virtual target mark instead of an alignment mark used in the conventional mask exposure, and perform an overlay per layer, such that the deposition exposure can be achieved in the maskless exposure.

Abstract: An alignment feature disposed on a substrate, the alignment feature including a first lithographic pattern having a first aggregate geometric center point defined by a first sub-pattern comprising alignment marks having a first sub-pattern geometric center point arranged a distance (d0) in a first direction from the first aggregate geometric center point, and a second sub-pattern comprising alignment marks having a second sub-pattern geometric center point arranged the distance d0 in a reciprocal direction of the first direction from the first aggregate geometric center point.

Abstract: A method for calibrating an apparatus for the position measurement of measurement structures on a lithography mask comprises the following steps: qualifying a calibration mask comprising diffractive structures arranged thereon by determining positions of the diffractive structures with respect to one another by means of interferometric measurement, determining positions of measurement structures arranged on the calibration mask with respect to one another by means of the apparatus, and calibrating the apparatus by means of the positions determined for the measurement structures and also the positions determined for the diffractive structures.

Abstract: The present invention is related to the semiconductor manufacturing field, especially a method for monitoring alignment between contact holes and polycrystalline silicon gate by setting a plurality of equidistant contact holes with same sharp on poly-silicon and residual active area, and then obtain the process alignment profile of the quantized values in the plane in order to have a better control of process quality, thereby have a better control of the quality of the process.

Abstract: A method is disclosed for measuring a profile of a reflecting face of an end (2) of a pipe section. An electrical field is generated between the face and suspended particles (19) in the ambient air of the face. The particles (19) are attracted to the face by the electrical field and matt-finishing the face. The face is then sensed with a laser beam (16) and scattered light (17) is reflected by the face and measured by a sensor (11), thereby determining a face profile.

Abstract: An improved method for optimizing layer registration during lithography in the fabrication of a semiconductor device is disclosed. In one example, the method comprises optimizing contact layer registration of an SRAM device having a plurality of transistors having active and gate region features extending generally along a channel length (X) direction and a channel width (Y) direction, respectively. The method comprises aligning a contact layer to a gate layer in the channel length direction (X), using gate layer overlay marks to control the alignment of the contact layer in the channel length direction (X) of the semiconductor device. The method further includes aligning the contact layer to an active layer in the channel width direction (Y), using active layer overlay marks to control the alignment of the contact layer in the channel width direction (Y) of the semiconductor device.

Abstract: An arrangement for providing passive alignment of optical components on a common substrate uses a set of reference cavities, where each optical device is positioned within a separate reference cavity. The reference cavities are formed to have a predetermined depth, with perimeters slightly larger than the footprint of their associated optical components. The reference cavity includes at least one right-angle corner that is used as a registration corner against which a right-angle corner of an associated optical component is positioned. The placement of each optical component in its own reference cavity allows for passive optical alignment to be achieved by placing each component against its predefined registration corner.

Abstract: An apparatus (AS) measures positions of marks (202) on a lithographic substrate (W). A measurement optical system comprises illumination subsystem (504) for illuminating the mark with a spot of radiation (206) and as detecting subsystem (580) for detecting radiation diffracted by the mark. The substrate and measurement optical system move relative to one another at a first velocity (vW) so as to scan the mark while synchronously moving the spot of radiation relative to the reference frame (RF) of the measurement optical system at a second velocity (vSPOT). The spot scans the mark at a third velocity (vEFF) which is lower than the first velocity to allow more time for accurate position measurements to be acquired. In one embodiment, an objective lens (524) remains fixed in relation to the reference frame while a moving optical element (562) imparts the movement of the radiation spot relative to the reference frame.

Abstract: A drive system drives a movable body, based on measurement results of a first measurement system which measures the position of the movable body in an XY plane by irradiating a measurement beam from an arm member on a grating placed on a surface parallel to the XY plane of the movable body and measurement results of a second measurement system which measures a variance of the arm member using a laser interferometer. In this case, the drive system corrects measurement errors caused due to a variance of the arm member included in the measurement results of the first measurement system, using the measurement results of the second measurement system.

Abstract: A semiconductor device includes an alignment mark formed over a semiconductor substrate and an inhibition pattern arranged over the alignment mark with a pattern edge of the inhibition pattern located in a mark functional region of the alignment mark in order to inhibit the alignment mark being recognized as such by an image detector of an exposure device.

Abstract: An embodiment provides a thin film transistor liquid crystal display (TFT-LCD) array substrate comprising a substrate and multilayer array patterns formed on the substrate, and a detecting mark, which is used to detect the size or alignment deviation of one array pattern among the multilayer array patterns and provided in a region of the substrate where the multilayer array patterns are not provided. The detecting mark comprises a detecting area and a detecting pattern which is provided in the same layer as the array pattern to be detected, the detecting pattern is located within the detecting area, and the detecting pattern has transmissivity or reflectivity different from that of the remaining area in the detecting area other than the detecting pattern.

Abstract: A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.

Abstract: A vision system is provided to determine a positional relationship between a semiconductor wafer on a platen and an element on a processing machine, such as a printing screen, on a remote side of the semiconductor wafer from the platen. A source directs infrared light through an aperture in the platen to illuminate the semiconductor wafer and cast a shadow onto the element adjacent an edge of the semiconductor wafer. A video camera produces an image using light received from the platen aperture, wherein some of that received light was reflected by the wafer. The edge of the semiconductor wafer in the image is well defined by a dark/light transition.

Abstract: An alignment method includes dividing a wafer into a plurality of regions including a first region and a second region, and each region contains a plurality chip areas. The method also includes obtaining alignment offset values for the first region, and determining a first alignment compensation equation for the first region. The method also includes obtaining alignment offset values for the second region, and determining a second alignment compensation equation for the second region. Further, the method includes determining whether a chip area to be exposed is in the first region or the second region, when the chip area is in the first region, using the first alignment compensation equation to adjust alignment of the wafer and, when the chip area is in the second region, using the second alignment compensation equation to adjust the alignment of the wafer.

Abstract: The present invention relates to light curtains, in particular safety light curtains, for monitoring a protective field. Furthermore, the present invention relates to optical units which are part of such a light curtain. An optical unit for an alignment system of a light curtain monitoring a protective field comprises an optical processing element for generating a defined radiation pattern from the radiation emitted by an alignment radiation source, and at least one additional optical functional element being formed integrally with the optical processing element.

Abstract: A projection exposure tool for microlithography for imaging mask structures of an image-providing substrate onto a substrate to be structured includes a measuring apparatus configured to determine a relative position of measurement structures disposed on a surface of one of the substrates in relation to one another in at least one lateral direction with respect to the substrate surface and to thereby simultaneously measure a number of measurement structures disposed laterally offset in relation to one another.

Abstract: A piping alignment tool suitable for locating where an extension of an existing pipe must pass through obstructions such as walls. The tool has a tubular shape with oppositely disposed ends. Each end is formed to have multiple coaxial sets of different-sized pipe threads that allow the tool to be threaded onto a pipe having one of the pipe thread sizes formed on the tool. The tool is also equipped to generate light beams from each end, so that the light beam can be emitted from an end of the tool opposite a pipe onto which the tool has been threaded. By threading the tool onto a pipe and emitting a light beam from the end of the tool opposite the pipe, the location of an obstruction beyond the existing pipe is illuminated by the emitted light beam.