Abstract: A system and method for correcting a scan pattern of a moving optical scanning system. A gantry moves an optical system at a constant rate in a first direction. Using a light source and a first deflector, the optical scanning system quickly sweeps a light beam in a direction orthogonal to the motion of the gantry by changing the angle of deflection of the first deflector linearly with time. To compensate for the motion of the gantry, the optical system includes a second deflector which deflects the light, the deflection angle being determined as a function of the velocity of the gantry. The deflected light is focussed on the object (or pattern). Accordingly, the object is scanned along a corrected scan line orthogonal to the X-axis. The optical scanning system may optionally perform "selected" scanning. Also, the optical system optionally employs a "look-ahead/look-behind" scanning approach to further improve the rate at which portions of an object (or pattern) may be inspected.

Abstract: A system is provided that simultaneously gathers three-dimensional and two-dimensional data for use in inspecting objects such as chip carriers for defects. Specifically, a source laser beam is directed to an object and forms a spot at the point of impingement at a known X-Y position on the object. The laser beam is reflected at the spot and light reflected off-axially with respect to the source laser beam is detected by two position sensing detectors (PSDs). Simultaneous to detecting off-axially reflected light, retro-reflected light (i.e., the light reflected approximately co-axial with the source laser) is detected by a photo diode array.

Abstract: An apparatus for detecting a polarization altering substance, such as ice, on a surface includes a polarizing filter on the surface between the surface and the polarization altering substance. When the polarizing filter includes alternating regions having orthogonal polarizing properties, only one viewing of the surface through a blocking filter is required. When light, either polarized or unpolarized, reflects off the surface, it passes through the polarizing filter and becomes polarized. Reflected light that additionally passes through ice after leaving the polarizer becomes unpolarized. When viewed through a blocking polarizer filter, polarized light passing through ice appears bright due to the unpolarizing effect of ice. On the other hand, polarized light not passing through ice retains its polarization and appears dark when viewed through a blocking filter.

Abstract: An apparatus for detecting a polarization altering substance, such as ice, on a surface includes a polarizing filter on the surface between the surface and the polarization altering substance. When the polarizing filter includes alternating regions having orthogonal polarizing properties, only one viewing of the surface through a blocking filter is required. When light, either polarized or unpolarized, reflects off the surface, it passes through the polarizing filter and becomes polarized. Reflected light that additionally passes through ice after leaving the polarizer becomes unpolarized. When viewed through a blocking polarizer filter, polarized light passing through ice appears bright due to the unpolarizing effect of ice. On the other hand, polarized light not passing through ice retains its polarization and appears dark when viewed through a blocking filter.

Abstract: A presence of a polarization altering substance on a specular surface is detected by transmitting light from a single strobed light source to the surface over a transmitting path and receiving the transmitted light from the surface. An intensity of the light is measured in both an optical non-isolator state and an isolator state by a same detector by delaying the non-isolated return light for a definite period of time before measuring it with the detector. The measured isolated and non-isolated intensities are converted to logarithmic form, range corrected, and compared to reference data established for the specific specular surface being investigated to detect the presence or absence of the polarization altering substance. Attenuation and backscattering effects of scattering and/or absorbing interference in the transmitted light are compensated so that the reference table is entered at the correct point. Using different intensities of transmitted light increases the dynamic range of the system.

Abstract: A method and apparatus are provided for efficiently using 3-D vision systems to measure selected structural features of objects that have a uniform geometric arrangement. The method and apparatus are particularly well suited for optimizing the 3-D measurement of a multiple lead frame, leads of integrated circuit devices mounted on the multiple lead frame, and ball grid array integrated circuit devices on a wafer. For obtaining the three-dimensional data, corresponding sides of the multiple lead frames or devices are scanned sequentially in a row or column with at least one three dimensional sensor. This scanning procedure is repeated for all rows and columns containing structural features of the devices for which data are to be obtained. The acquired three-dimensional device geometry data are compared with the intended predetermined geometry to produce a signal indicative of a deviation of an actual device geometry from the intended predetermined geometry that exceeds a specified tolerance.

Abstract: Methods and arrangements are provided to efficiently use 3-D vision systems to measure selected features, of objects that are semi-constrained in compartmented trays having a uniform geometric arrangement. The methods are particularly well suited for optimizing the 3-D measurement of leads on integrated circuit devices which are packaged in trays. For obtaining the three-dimensional data, a multi-pocketed tray can be provided with tray pockets arranged in rows and columns, and corresponding sides of the multiple parts or devices in a row or column are scanned sequentially with at least one three dimensional sensor. This scanning procedure is repeated for all rows and columns containing sides of the devices from which data is to be obtained. The devices can be first aligned by applying directional vibration to the tray to drive all the parts or devices to the same corner or side of the respective pockets.

Abstract: A three dimensional sensor includes an illumination source that produces broadband, high intensity optical energy. This optical energy includes a number of individual wavelength components. The individual wavelength components are impinged in a spot on a target. Dispersion is applied to the light reflected from the spot, either before target impingement, after target impingement, or both, whereby light of different colors is focused at different distances from the target. A maximum reflected wavelength, dependent on target range, is detected to determine the target range. In one embodiment, temporal modulation is applied to the light before target impingement. A stationary detector determines the target range by relating the maximum light received to the time it is received in order to determine the color received at that time. In another embodiment, all colors are reflected from the target simultaneously, and the reflected beam is chromatically dispersed in the transverse direction.

Abstract: A position sensing detector in which each of a plurality of sensing channels is provided with ends and an output current lead at each end of each channel. A light spot is imaged along the length of the channel. The channels are electrically isolated from each other. The channels may be proportional to a selected keystone pattern, and the channels may be rectangular-shaped and accommodate keystoning effects of an imaged beam.

Abstract: A scanning system inspects elements, such as ICs, continuously by positioning a second tray containing elements to be inspected adjacent a scan bed in which the elements in a first tray are being scanned. Immediately upon completion of scanning of elements in the first tray, scanning begins on elements in the second tray. During scanning of the second tray, the first tray is off loaded, and a third tray replaces the first tray. The cycle is repeated continuously. Since transport and scanning operations take place simultaneously, transport delay is reduced substantially, as compared to the serial system of the prior art. When the transport, positioning, and off loading operations consume substantially less time than the scanning operation, a fresh tray of elements always awaits scanning upon completion of scanning of elements in a tray.

Abstract: Methods and arrangements are provided to efficiently use 3-D vision systems to measure selected features, of objects that are semi-constrained in compartmented trays having a uniform geometric arrangement. The methods are particularly well suited for optimizing the 3-D measurement of leads on integrated circuit devices which are packaged in trays. For obtaining the three-dimensional data, a multi-pocketed tray can be provided with tray pockets arranged in rows and columns, and corresponding sides of the multiple parts or devices in a row or column are scanned sequentially with at least one three dimensional sensor. This scanning procedure is repeated for all rows and columns containing sides of the devices from which data is to be obtained. The devices can be first aligned by applying directional vibration to the tray to drive all the parts or devices to the same corner or side of the respective pockets.

Abstract: A scanning system inspects elements, such as ICs, continuously by positioning a second tray containing elements to be inspected adjacent a scan bed in which the elements in a first tray are being scanned. Immediately upon completion of scanning of elements in the first tray, scanning begins on elements in the second tray. During scanning of the second tray, the first tray is off loaded, and a third tray replaces the first tray. The cycle is repealed continuously. Since transport and scanning operations take place simultaneously, transport delay is reduced substantially, as compared to the serial system of the prior art. When the transport, positioning, and off loading operations consume substantially less time than the scanning operation, a fresh tray of elements always awaits scanning upon completion of scanning of elements in a tray.

Abstract: An arrangement for inspecting straightness of an array of pins in which the array is illuminated by a thin beam of light. Images of surfaces of the array of pins that are illuminated are projected on a photo-sensitive device. The array of pins is movable relative to the beam of light and the imaging device. The imaging device and photo-sensitive device are also movable relative to the array of pins.

Abstract: A method and apparatus for detecting a presence of a polarization altering substance on a specular surface includes transmitting light to the surface over a transmitting path and receiving the transmitted light from the surface and from the polarization altering substance. An intensity of the light is measured in an optical non-isolator state and in an isolator state. The isolator and non-isolator state measurements are performed either sequentially or simultaneously. A difference in intensity between isolator and non-isolator states indicates an absence of the substance. A sameness in intensity between isolator and non-isolator states indicates a presence of the substance.

Abstract: Methods and arrangements are provided to efficiently use 3-D vision systems to measure selected features, of objects that are semi-constrained in compartmented trays having a uniform geometric arrangement. The methods are particularly well suited for optimizing the 3-D measurement of leads on integrated circuit devices which are packaged in trays. For obtaining the three-dimensional data, a multi-pocketed tray can be provided with tray pockets arranged in rows and columns, and corresponding sides of the multiple parts or devices in a row or column are scanned sequentially with at least one three dimensional sensor. This scanning procedure is repeated for all rows and columns containing sides of the devices from which data is to be obtained. The devices can be first aligned by applying directional vibration to the tray to drive all the parts or devices to the same corner or side of the respective pockets.

Abstract: A method and apparatus for detecting a presence of a polarization altering substance on a specular surface includes transmitting light to the surface over a transmitting path and receiving the transmitted light from the surface and from the polarization altering substance. An intensity of the light is measured in an optical non-isolator state and in an isolator state before being compared to reference data established for various specular surfaces. The reference data are preferably established by measuring an intensity of the light in both an optical non-isolator state and in an isolator state for a known surface when the polarization altering substance is absent from the known surface.

Abstract: An arrangement for steering the laser beam, in an active optical triangulation method based on three-dimensional sensors, along paths which are sensitive to the context of the scene of interest, and alleviating the need to undergo a search path by the sensor. A conventional video camera is used to preview the scene of interest and the resultant intensity image is processed to locate the desired path based on the scene context. The sensory system is modeled to enable determination of the instantaneous angular deflections of the laser beam along with the translation of the laser source that can shift the nominal or actual data acquisition path to the desired data acquisition path.

Abstract: A position sensing detector in which each of a plurality of sensing channels is provided with ends and an output current lead at each end of each channel. A light spot is imaged along the length of the channel. The channels are electrically isolated from each other. The channels may be proportional to a selected keystone pattern, and the channels may be rectangular-shaped and accommodate keystoning effects of an imaged beam.

Abstract: A system for detecting the presence of an energy polarization altering dielectric material, such as ice or snow, on a surface, such as a part of an aircraft, which normally specularly reflects incident energy, such as light, when there is no such dielectric present. The energy is conveyed from a transmitter along a path to the surface and the incident energy is reflected from the surface along a path to a receiver with a dielectric on the surface destroying any polarization, such as circular, of the energy and that reflected from a specular portion maintaining the polarization. An optical system in one or both of the paths operates in an isolator state to produce an image of the dielectric portion having a first intensity level and that of the specular portion passing through the optical system having a different intensity level.

Abstract: A system for detecting the presence of an energy polarization altering dielectric material, such as ice or snow, on a surface, such as a part of an aircraft, which normally specularly reflects incident energy, such as light, when there is no such dielectric present. The energy is conveyed from a transmitter along a path to the surface and the incident energy is reflected from the surface along a path to a receiver with a dielectric on the surface destroying any polarization, such as circular, of the energy and that reflected from a specular portion maintaining the polarization. An optical system in one or both of the paths operates in an isolator state to produce an image of the dielectric portion having a first intensity level and that of the specular portion passing through the optical system having a different intensity level.