Abstract: A pattern of light is projected upon a surface to be measured which may be devoid of surface detail. A sharply focused image of the surface provides distance discrimination. Although the projected pattern may be separate from the imaging optics, a common optics path removes distortion, provides maximum sensitivity and eliminates processing for misalignment between projector and imager. Parallel detection of regions within the image receiving light intensities above a threshold enables rapid availability of measurements. Optical cross-correlation and Fourier transform processing methods may be employed to enhance image processing with no processing delay. Three-dimensional co-ordinate measurements relative to the sensor are reported for all in-focus regions of the image. Refocusing the lens provides depth coverage.

Abstract: The physical location of a surface in six degrees of freedom relative to the nominal location of a nominal surface is uniquely defined automatically by a measurement system provided with a processing unit, if sufficient asymmetric curvature exists in the surface to uniquely locate three points on the surface. Useful in inspection and material handling applications, a master model of the surface with a known location is defined. Two points are selected on the surface and then a plane is passed through the points, preferably perpendicular to the surface if no edge is present. Then a third point is selected along the curve of intersection so that the three points form a unique triangular template that locates the points along the curve. If the three points are on a sharp edge of the surface this may be adequate information.

Abstract: Methods are provided for reducing the number of projected patterns required to make two- or three-dimensional surface measurements on a sub-class of surfaces comprising relatively smooth surfaces. By including apriori knowledge about the surface to be measured, pattern ambiguities can be resolved by processing rather than by additional projected patterns.

Abstract: Methods are provided for reducing the number of projected patterns required to make two- or three-dimensional surface measurements on a sub-class of surfaces comprising relatively smooth surfaces. By including apriori knowledge about the surface to be measured, pattern ambiguities can be resolved by processing rather than by additional projected patterns.

Abstract: An apparatus with a common aperture and multiple image recording surfaces with individual filters and/or controlled shutters enables the implementation of several methods of 3-D measurement systems. The parallel nature of the device lends to short measurement times suitable for measuring moving objects. A similar apparatus may be constructed to project multiple images simultaneously or in rapid succession. Elimination of mechanical motion within the projectors and cameras of the prior art reduce the measurement time significantly. A new method of 3-D measurement employing a sweeping light plane and time encoded image recording uses the apparatus. An alternate method maintains a stationary projected light plane through which an object moves as it is measured in 3-D. Another method uses simultaneous projection of light patterns at different frequencies. Another method employs the time of flight of a light pulse and time encoded recording of the reflected energy.

Abstract: A pattern of light is projected upon a surface to be measured which may be devoid of surface detail. A sharply focused image of the surface provides distance discrimination. Although the projected pattern may be separate from the imaging optics, a common optics path removes distortion, provides maximum sensitivity and eliminates processing for misalignment between projector and imager. Sequential cross-correlation, synchronous detection or percent modulation processing methods may be readily implemented to develop three-dimensional co-ordinates relative to the sensor for all in-focus regions of the image. Refocusing the lens provides depth coverage.

Abstract: An object is scanned first with a light plane from a variable-intensity light-plane projector, and the reflected light is used as signals to modify point by point the output of the projector in accordance with the intensity of the respective reflective-light signal. Thereupon the object is scanned a second time and the projector is instructed to apply less light than before to those points of the object from which a strong reflected-light signal was received during the first scan, and/or to apply more light to points from which a weak reflected-light signal was received during the first scan. In similar manner, a projected intensity encoded light volume is projected on an object and the reflected light is used as signals to point-by-point modify the output of the projector for subsequent projections.

Abstract: Cameras or optical devices requiring shutters to allow light to reach a light sensitive area from an object scene for a prescribed amount of time are provided with an electrically controlled light modulator to replace mechanical shutters. Cameras or optical devices requiring a variable aperture and/or transform filter to adjust the amount of light admitted, depth of focus and/or image enhancement are also provided with electrically controlled light modulators to replace mechanical apertures and transform masks. Both functions may be incorporated into a single electrically controlled light modulator.

Abstract: Light intensity levels are measured at various locations in a scene and light amplified and/or attenuated by a device interposed between the source of light and the light-sensitive surface having a limited dynamic range. By attenuating bright regions and/or amplifying weak regions, the dynamic range of light intensities of the scene is reduced, thus enabling the limited dynamic range device to be used with scenes having a larger light intensity dynamic range. In applying the method to the receiving side of a 3-D measurement system employing projected light, a simpler system results and problems associated with modifying the high energy projected light are avoided. Also, a greater range of measured object surface reflectance is accommodated.

Abstract: An arrangement for deflecting a beam of monochromatic light in a rapid and accurate manner. To deflect the beam, segments of a number of Fresnel lenses are produced onto a single flat glass substrate disk. The optical axis of each of the lens segments corresponds to the center of rotation of the disk. The disk is mounted on a shaft which is rotatable about that optical axis. The beam of light to be deflected is applied to the surface of the disk at a point off the axis. When the beam passes through the disk it becomes deflected by one of the lens elements. The degree of deflection depends on the nature of the element, and the rate at which the beam is deflected from one orientation to another is determined by the rate of rotation of the disk.

Abstract: An arrangement of partially reflecting mirror surfaces to extend the dynamic range of area sensor arrays as used in optical measurement systems. An instantaneous optical AGC allows a single area sensor to be used in inspection systems where surface reflectivities and characteristics may vary from diffuse to mirror-like. The partially reflecting mirrors instantaneously superimpose on the area sensor a set of spatially displaced energy related images of the inspection pattern. Electronic readout of the sensor and subsequent data processing allows selection of portions of each image which represent the linear non-blooming operating range of the sensor.

Abstract: An arrangement for eliminating erroneous data in three-dimensional optical sensors, in which a point on a surface is illuminated, and reflections from the point are received at a first location spaced from the source of illumination. The three-dimensional location of the point is computed as a function of the reflection that is received at the first location. The procedure of illuminating the point is repeated for obtaining reflections from the point at a second location which is spaced from the first location and the illuminating source. After computing the three-dimensional location of the point obtained from data dependent on the reflection at the second location, the computations relative to the first and second locations are compared. If the computations produce substantially identical results, the point is designated to be a true point on the surface.

Abstract: A plurality of projectors are positioned in spaced relationship about an object with a surface to be geometrically analyzed. The projectors have cooperating masks which project onto the object illuminated patterns that subdivide the object into predetermined sections. Each mask has a predetermined pattern of sections, and is applied in sequence. The masks are cooperatively advanced in the projectors, with a separate illuminating pattern prevailing on the object each time that the masks are advanced. The combinations of the patterns on the masks define closely-spaced sections subdividing the object. The patterns are coded so that each section is uniquely defined in coded form. Cameras having the entire object within their field of view, photograph the object each time a separate mask is applied.

Abstract: The surface to be sensed or scanned is placed in the path of a projector which is moved along an axis of the surface. The path of motion of the projector is subdivided into predetermined sections which are illuminated by the projector in accordance with a predetermined sequential pattern. This procedure of moving the projector is repeated a predetermined number of times, with a separate illuminating pattern prevailing each time that the projector is moved relative to the surface and traverses the entire surface to be scanned. The combinations of the patterns obtained from the repeated scannings of the projector define closely-spaced sections of the surface. The patterns are coded so that each section is uniquely defined in coded form. A camera having the entire surface within its field of view photographs the surface each time that the projector is moved along the axis of the surface.

Abstract: An object is scanned first with a flying light spot from a variable-intensity light-spot projector, and the reflected light is used as signals to point by point modify the output of the projector in accordance with the intensity of the respective reflective-light signal. Thereupon the object is scanned a second time and the projector instructed to apply less light than before to those points of the object from which a strong reflected-light signal was received during the first scan, and to apply more light to points from which a weak reflected-light signal was received during the first scan.

Abstract: The invention discloses a method of determining the position and orientation of an element (such as a platform) in space by determining the intersection of a line with a plane (or with another line). Three different implementations are disclosed.

Abstract: Rays or planes of light in space are addressed, according to this invention, by purely electrical commands and without the need for mechanically moving parts.

Abstract: A method for locating points on a surface in which the surface is irradiated selectively with an irradiating volume which has a varying intensity that defines a first pattern. After irradiating the surface with the first pattern, the surface is irradiated similarly with volumes having varying intensities defining a second or more patterns. Both of these patterns are applied to a point to be located on the surface. The radiation impinging on the surface is recorded by a camera which forms images of the patterns. The images are scanned to find the intensities of the point in the two or more patterns. More than one pattern may be simultaneously irradiated, using different frequencies to distinquish the data. The location of the point on the surface is dependent on a predetermined ratio or difference of the intensities of the point in the two or more patterns.

Abstract: A method for locating points on a surface, in which the surface is irradiated selectively with an irradiating volume which has a varying intensity that defines a first pattern. After irradiating the surface with the first pattern, the surface is irradiated similarly with volume(s) having varying intensity(ies) defining a second (or more) pattern(s). Both (or all) of these patterns are applied to a point to be located on the surface. The radiation impinging on the surface is recorded by a camera which forms images of these patterns. The images are scanned to find the intensities of the point in the two (or more) patterns. The location of the point on the surface is dependent on a predetermined ratio or difference of the intensities of the point in the two (or more) patterns. The patterns may be linear, sinusoidal, smooth, non-smooth and/or two dimensional functions ultimately producing a single valued ratio or difference result.

Abstract: Damage to tools and/or equipment (such as measuring equipment) mounted on industrial robot systems or other positioning systems tending to drop when electrical power is cut off, is eliminated by auxiliary equipment which prevents such dropping.