WO2008108749A1

WO2008108749A1 - Desktop three-dimensional scanner

Info

Publication number: WO2008108749A1
Application number: PCT/US2007/001145
Authority: WO
Inventors: Mark S. Knighton; David S. Agabra; Vlad Constantin Cardei; Jeremy A. Millers; Mark A. Feeney; William D. Mckinley
Original assignee: Nextpat Limited
Priority date: 2006-01-20
Filing date: 2007-01-16
Publication date: 2008-09-12

Abstract

A system having a scanner capable of capturing three dimensional measurement data about a target surface having a housing retaining an image sensing array and a light source is disclosed. The scanner is capable of capturing an area of the target surface spanning at least two square inches in a single capture field. The scanner has a bounding box circumscribing a projected footprint of the housing on a work surface during operation of the scanner having an area of no more than sixty-five square inches. The system further includes a positioner capable of actively reorienting an object. The scanner and positioner may have an aggregate footprint during operation of no more than ninety five square inches.

Description

DESKTOP THREE-DIMENSIONAL SCANNER

BACKGROUND

Field

The invention relates to a desktop scanner for capture of three- dimensional data. More specifically, the invention relates to a high speed high resolution desktop scanner having a compact size and a large field of view for image capture.

Background

Historically, three-dimensional digitizing has been relegated to the laboratory or specialized scanning entities as a result of system constraints, system cost and system size. For example, light constraints and/or need for a specialized background have forced scanning into a dark room or other environment where ambient conditions can be controlled. Many commercially available systems cost upwards of ten thousand dollars making them largely impractical for personal use.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to "an" or "one" embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

FIG. 1 is a perspective view of a desktop scanner system of one embodiment of the invention.

FIG. 2 is a perspective view of a desktop scanner of one embodiment of the invention having a portion removed. FIG. 3 is a perspective view of internal components of a desktop scanner of one embodiment of the invention.

FIG. 4 is a block diagram of a desktop scanner system of one embodiment of the invention.

FIG. 5 is a perspective view of a turntable of one embodiment of the invention.

FIG. 6 is a perspective view of a turntable of one embodiment of the invention.

DETAILED DESCRIPTION

There are many contexts in which high performance compact desktop scanners having minimal interstices and a large field of view may be desirable. Among these contexts is where a user desires control of image capture at their desktop without sacrificing work space, image quality and a large field of view.

FIG. 1 is a perspective view of a desktop scanner system of one embodiment of the invention. The system includes a scanner housing 102 connected to a base 104. Base 104 includes a port 110 allowing for connection of scanner 100 to a turntable 114. This port may permit wired connection or wireless connection such as infrared (IR) or radio frequency (RF) signaling to the turntable. Housing 102 may be connected to base 104 by any conventional securing mechanism, including but not limited to screws, bolts, adhesives or any similar securing mechanism. In one embodiment, housing 102 may be formed from aluminum sheets formed to the desired shape. In another embodiment, housing 102 may be molded out of glass filled Acrylonitrile Butadiene Styrene (ABS). Similarly, base 104 may be molded out of ABS. Housings and bases made of other plastics or metal are all within the scope and contemplation of the invention. Housing 102 may be dimensioned such that it occupies only a small portion of the desktop work surface. In one embodiment, a bounding box 112 circumscribing a projected footprint of housing 102 on a work surface at any time during operation has an area of no more than sixty five square inches (sq. inches). As used herein "projected footprint" means the portion of the work surface that would be shadowed when light is projected normal to the upper surface of the scanner. Indicating that the projected footprint "at any time during operation" is intended to encompass those scanners that expand, telescope, or otherwise move out of the original volume during operation. Attachment of a nonfunctional structure to the housing that does not impede use of the work space is not deemed to increase the projected footprint. For example, a flexible desk matt attached to the scanner such that the non- overlapping area remains usable work space is not deemed to increase the projected footprint. In one embodiment, bounding box 112 has a length L' substantially equivalent to a length L of a top surface 126 of housing 102 and a width W substantially equivalent to a width W of top surface 126. It is further contemplated, however, that where housing 102 has sides or a base extending out beyond top surface 126, U and W of bounding box 112 may be defined by such portions of housing 102. Thus, in an embodiment having a bounding box 112 of less than sixty-five sq. inches, L and W of top surfacel26 are approximately 11" and 5.8" respectively, therefore projected footprint L' x W is approximately 11" x 5.8". In another embodiment, housing 102 has a projected footprint of approximately 9.8" x 4.5, or a bounding box 112 of less than forty- five sq. inches. In another embodiment, housing 102 may be dimensioned such that bounding box 112 is less than thirty-five sq. inches. In an alternative embodiment, housing 102 has a projected footprint of approximately 8.8" x 3.6" or a bounding box less than 32 sq. inches. In one embodiment, scanner 100 has a height of 10.9". In an alternative embodiment, scanner 100 may have any height suitable for desktop operation. It is further, within the scope and contemplation of the invention that housing 102 may be dimensioned to have a bounding box 112 of any size suitable for minimizing the amount of desktop space occupied by scanner 100.

In one embodiment, a positioner 114 for actively reorienting object 124 may be provided. Positioner 114 may, in one embodiment, be a turntable having a plate 120 rotatably coupled to a turntable housing 116 which is in turn coupled to a base 118. Turntable 114 may be of the type described in U.S. Patent No. 6,530,550 assigned to the assignee of the instant application. In one embodiment, turntable 114 is a discrete unit from scanner 100. In this aspect, scanner 100 and turntable 114 may be arranged in any manner upon the desktop so as to optimize usability of desktop space surrounding the scanning system. In one embodiment, turntable 114 may be positioned close to a front side of scanner 100 to minimize unnecessary interstices between scanner 100 and turntable 114. For example, in one embodiment, a side of turntable 114 facing a front side of scanner 100 may be positioned less than seven inches from the front side of scanner 100. Although seven inches is described, it is within the scope and contemplation of the invention to position turntable 114 any distance from the front of scanner 100 within a focal length of scanner 100. In an alternative embodiment, scanner 100 may be placed upon the desktop while turntable 114 is positioned on another work surface near the desktop to free up work space on the desktop.

In one embodiment, turntable 114 may be dimensioned such that a second bounding box 122 circumscribing turntable 114, and bounding box 112, in the aggregate, have a projected footprint area on the work surface, at any time during operation, of no more than ninety square inches. In one embodiment, bounding box 122 has a length /' substantially equivalent to a length / of a top surface 128 of housing 116 and a width w' substantially equivalent to a width w of top surface 128. It is further contemplated, however, that where housing 116 has sides or a base extending out beyond top surface 128, /' and w' of bounding box 122 may be defined by such portions of housing 116. In one embodiment, turntable 114 has a projected footprint of approximately 7.6" x 7.6" or a bounding box 122 less than fifty-eight sq. inches. In another embodiment, turntable 114 may be dimensioned such that bounding box 122 is between forty-five sq. inches and fifty-eight sq. inches. In another embodiment, turntable 114 has a projected footprint of approximately 6.7" x 6.7" or a bounding box 122 less than forty-five sq. inches. In another embodiment, turntable 114 may be dimensioned such that bounding box 122 is between forty-two sq. inches and forty-five sq. inches. In another embodiment, turntable 114 has a projected footprint of approximately 6.5" x 6.5" or a bounding box less than forty-two sq. inches. It is, however, within the scope and contemplation of the invention that turntable 114 may be dimensioned to have a bounding box 122 smaller than forty- two square inches to minimize the amount of desktop space occupied by turntable 114.

It is desirable to minimize the aggregate area of the combined scanner 100 and positioner 114. This can be accomplished by reducing the size of either element individually. Alternatively, other positioners such as a robotic arm etc. are within the scope and contemplation of embodiments of the invention.

A projection unit 130 may be positioned within a projection region 106 defined by housing 102 to project a light pattern element toward a target object 124 positioned on turntable 114. As used herein, "target" refers to all or some portion of a three-dimensional object. As will be discussed in detail below, in one embodiment, projection unit 130 moves light pattern elements relative to a surface of target object 124. As used herein, movement "relative" to the target means either the pattern element moves, the target moves, or both.

Housing 102 further defines an image capture region 108. Cameras 132, 134 may be retained within capture region 108 in fixed relation relative to projection unit 130. In one embodiment, camera 132 is focused at a distance of eighteen inches from the scanner and second camera 134 is focused seven inches from the scanner. While focal distances of seven inches and eighteen inches have been chosen, other focal distances are within the scope and contemplation of the invention. Cameras 132, 134 include an image sensing array (ISA). In one embodiment, the ISA is an area charged coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor, having a focal zone and field of view directed at an angle towards a pattern projected by projection unit 130. In one embodiment the CMOS sensor may be a three megapixel area CMOS sensor such as the OVT 3620 available from Omnivision Technologies, Inc. of Sunnyvale, California. Higher or lower density sensors may be used in various embodiments of the invention. In one embodiment, cameras 132, 134 use the Omnivision chip and lenses from Genius Electronic Optical Co., Ltd of Taiwan under Part No. GS-8236D. In other embodiments, only a single camera may be used while in other embodiments, multiple cameras having a particular focal distance may be employed to provide for over sampling and reduce the occurrence of occlusions. In some embodiments, the camera may be on a drive system and be able to change their focus to different ranges.

In one embodiment, image capture involves two phases. The first phase includes capturing a texture of object 124. The second phase includes capturing a geometry of object 124. In one embodiment, the same camera is used to capture both texture and three-dimensional measurement data. Alternatively, one camera may be used to capture texture data and a second camera may be used to capture three-dimensional data. Such a two phase imaging system allows for capture of multiple contours of object 124 within the same time frame. This data set may then be processed by scanner 100 or alternatively, a host node 404 (Shown in FIG. 4).

In the embodiments described above, no motion of any part of scanner 100 occurs outside of its original volume during operation to ensure the maximum amount of desktop space remains usable. Thus, the only component of the scanning system separate from scanner 100 is turntable 114. It is therefore, only regions of the desktop under bounding boxes 112, 122 and interstices between these regions which are occupied by the system during operation. Such a configuration is particularly desirable since those using desktop scanners typically have a limited amount of desktop work space within which to perform image capture and analysis, as well as perform other unrelated tasks. This workspace becomes further limited by scanning systems having multiple external parts that must be arranged on the desktop surface. Moreover, in the case of moving parts, not only are portions of the desktop in contact with each part unusable, but portions of the desktop within the range of movement of each part must be kept clear so as not to interfere with operation of the device.

Scanner 100 captures an area of a surface of object 124 in a single capture field. In one aspect, the single capture field is equivalent to a field of view of the ISA. Alternatively, the single capture field may be a single capture sequence including panning the ISA across object 124 to capture images of portions of the object surface for each successive displacement of the ISA and aggregating these portions to form a single composite image of object 124. In one embodiment, the ISA captures an area of a surface of object 124 spanning two sq. inches in a single capture field. In one embodiment, the ISA may capture an area of the surface of object 124 spanning more than two sq. inches in a single capture field. In other embodiments, the capture field may be greater than four, eight, twelve or sixteen sq. inches at less than eight inches from the scanner. In another embodiment, the ISA may capture an image of target 124 having an area of 5.1" x 3.8" inches or fewer at a distance of seven inches without resolution of 0.005". In other embodiments, the scanner has a capture field greater than 30, 60, 90 or 120 sq. inches at less than twenty inches from the scanner. In an alternative embodiment, the ISA may capture target 124 fitting within a 10.1" x 13.5" area at eighteen inches from the scanner with a resolution of 0.012". Thus, in spite of the reduced scanner size, a relatively large field of view for image capture is maintained so that the system is suitable for use in a variety of applications. As previously discussed, cameras 132 and 134 may be retained within capture region 108 in fixed relation relative to projection unit 130. The distance between the cameras and projection unit is selected to achieve optimal image quality while still maintaining a desktop sized scanner 100. In particular, in one embodiment it is desirable to keep the distance between camera 132 and projection unit 130 small such that a narrow angle is created at an intersection between each pixel focal line and laser plane. A narrower angle reduces the likelihood of occlusions during image capture. A narrower angle, however, reduces the resolution of the image. Thus, where a higher resolution is desired, the distance between the camera and projection unit may be increased so that the angle between the pixel focal line and laser plane is increased. For example, in one embodiment where it is desirable to achieve a five-thousandth resolution, a distance between a projection unit and camera having focal lengths of eighteen inches may be approximately six inches and the angle at the intersection between the pixel focal line and laser plane may be approximately eighteen degrees. In another embodiment having a camera and projection unit with focal lengths of seven inches, a five- thousandth resolution may be achieved by a distance of two and one half inches between the camera and projection unit and an angle of approximately twenty-two degrees.

It is recognized, however, that increasing the distance between the projection units and corresponding cameras may in turn increase the device size. Thus, in one embodiment, the distance between the projection unit and cameras is selected based upon the desired scanner size. For example, in one embodiment, the distance between the projection unit and camera may be no larger than a desired width of scanner 100. Accordingly, in one embodiment, where it is desirable for scanner 100 to be no more than eight inches wide, the distances between the projection unit and cameras 132, 134 is no more than eight inches. Ideally, however, device size and desired resolution are balanced to achieve a relatively small device while still maintaining optimal resolution. Angles in the range of about fifteen degrees to twenty-five degrees have been found satisfactory for five-thousandths of an inch resolution and permit a sufficiently compact overall device size.

FIG. 2 is a perspective view of a desktop scanner of one embodiment of the invention having a portion removed. Scanner 100 is shown with a front panel removed. A texture light source 200 for illuminating the surface of object 124 during capture of the object texture is shown coupled to a mounting surface 204 within housing 102. A second texture light source 202 may be mounted to mounting surface 204 below light source 200. In one embodiment, light sources 200, 202 may be fluorescent light bulbs, such as the commercially available thirteen watt fluorescent bulb available from Greenlite Lighting Corporation of Quebec, Canada, available under the part number CFL-13W- TT. Bulbs 200, 202 are used to provide diffused light to permit texture capture. By having bulb 200 above the cameras and bulb 202 below the cameras shadowing of the targets is reduced. It has been found that the relative length of the light source helps to diffuse the light, reduces glare, and improves the quality of texture data captured by the scanner. Thus, in one embodiment, texture light sources 200, 202 may have at least two points of emission separated by at least five inches to ensure the portion of object 124 to be captured is sufficiently illuminated for capture of the texture of object 124. In this aspect, texture light sources 200, 202 may be fluorescent light bulbs at least five inches in length. In practice, a fluorescent bulb may be thought of as a series of point sources within the length of the bulb. In an alternative embodiment, light sources 200, 202 may be multiple point sources such as flash bulbs with a maximum separation of at least five inches.

FIG. 3 is a perspective view of internal components of a desktop scanner of one embodiment of the invention. A mounting structure 300 provides a platform on which the other components of the scanner may be retained. In one embodiment, cameras 132, 134 may be coupled to mounting structure 300. Camera 132 is retained by a first camera mounting plate 304. Similarly, second camera 134 is retained by a second camera mounting plate 306. The cameras are retained in fixed relation relative to projection unit 130. In one embodiment, camera 132 is focused at a distance of eighteen inches from the scanner and second camera 134 is focused seven inches from the scanner. While focal distances of seven and eighteen have been chosen, other focal distances are within the scope and contemplation of the invention.

Circuit board mounting plate 308 extends from mounting structure 300 and provides a platform on which circuit boards necessary for operation of the system may be mounted. A circuit board 310 is mounted thereto. In one embodiment, there might be multiple circuit boards mounted to circuit board mounting plate 308 including a power board and a digital board. The power board supplies power to the various subsystems of the scanner. The digital board controls the operation of the scanner subsystems.

Projection unit 130 includes a pair of manifolds 312, 314 mounted to a rotary axis 316 about which the manifolds can be rotated by a pan drive motor 318 via a gear box 320. Gear box 320 may include a number of composite gears 322, 324 and 326. Gear 328 engages a drive gear 330 mounted to rotary axis 316. The gears may be molded out of plastic or any other suitable material. Drive gear 330 may be molded out of glass filled Acrylonitrile Butadiene Styrene (ABS) and may have a home blade (not shown) molded as a part thereof. The home blade is positioned to pass through an optical interrupter 332. Optical interrupter 332 senses the blade and provides indication when the projection unit 130 is in a home position. Also attached to a rotary axis to move therewith is position encoder 334. In one embodiment, position encoder 334 may be a printed piece of material such as plastic having a plurality of high density lines printed thereon. In one embodiment, position encoder 334 has 360 lines per inch printed thereon. Alternatively, position encoder 334 may have 500 lines per inch printed thereon. A quadrature encoder 336 is positioned such that the printing on position encoder 334 passes through and is read by the quadrature encoder 336 as projection unit 130 rotates about the axis 316. Through the quadrature encoder it is possible to discern to a high degree of accuracy the precise angular position of projection unit 130.

A fan 350 is provided for cooling pan drive motor 318. Fan 350 may be mounted to the base portion of structure 300. Fan 350 may be any commercially known fan dimensioned to fit within scanner 100. In one embodiment, fan 305 may be used to cool other internal components, including but not limited to, the laser diodes and circuit boards.

As previously noted, a pair of manifolds 312, 314 are mounted to the rotary axis 316. In the shown embodiment, each manifold includes four ports 338 through which a light pattern element may be projected on a target. In other embodiments, more or fewer ports may be provided. For example, manifolds with eight, twelve, sixteen and thirty- two ports are contemplated. In one embodiment, laser diodes provide an optical communication with each port of each of the manifolds.

Channels are arranged in each manifold to ensure angular diversity between the projected light elements. As used herein, "angular diversity" means that either adjacent angles formed by the projection unit are different, or that for any group of projection elements selected, the angle formed is unique. At the limit, the angle formed by any two pairs of projected light pattern elements is unique. An example of the second case might be in a nine laser embodiment: given angles between respective adjacent lasers of 2°; 2°; 3°; 3°; 4°; 4°; 5°; 5°; for any group of three lasers, a unique angle exists. By using the laser groupings to establish uniqueness, greater laser density can be achieved without improving mechanical tolerances.

Laser diodes 340 are positioned to be at optical communication with collimating lenses (not shown) and spreading lenses 342. Collimating lens focuses the emissions from laser diodes 340 into a laser spot. Spreading lens 342 then spreads the spot into a laser stripe 348 which may be projected onto a target. Spring arms (not shown) permit the laser diode to be positioned within the channel to change the focal length of the laser diode. Power lines 344 run from laser board 346 to the laser diodes to permit the lasers to be powered and controlled during operation. The stripes emitted from spreading lenses 342 projected back to the axis converge to an axis substantially parallel to and possibly collinear with the axis of rotation 316 of the projection unit.

Manifolds 312, 314 are identically configured. However, the positioning of the laser diodes within the manifolds permits the laser stripes emitted by the respective manifolds to be focused at eighteen or seven inches from the unit consistent with the focal distance of cameras 132, 134 respectively. As noted above, manifolds 312 and 314 are manufactured such that pairs of ports define a unique angle relative to any other pair of ports for the particular manifold. In other embodiments, the ports may merely insure that the angle between any two adjacent ports is different. This angular diversity facilitates disambiguation of the laser planes. While four ports and correspondingly four lasers per manifold are shown in FIG. 3 manifolds permitting the use of more or fewer lasers are contemplated. For example, manifolds for twelve or sixteen lasers might be used in alternative embodiments of the invention. The larger the number of lasers, the faster it is possible to scan a particular target. The limitations on the number of lasers is constrained by manufacturing tolerances and the overall size of the unit desired.

Collimating lens may be a collimating lens, such as that available from Union E-O Technology Co., Ltd of Taiwan available under the Part Number LC-5. In one embodiment, spreading lenses 342 may be a customized spreading lens. Spreading lens 342 may be customized so as to create a substantially uniform laser stripe over the desired field of view. In one embodiment, spreading lens 342 is customized to make the laser plane exactly as long as needed for the particular laser and collimating lens combination, so as not to waste any laser power or miss the edges of the field of view. In another embodiment, spreading lens 342 may be customized to have a particular size which allows for multiple lasers to be packed close together within the manifolds. In one embodiment, spreading lens 342 may be made of a plastic material. In some embodiments, a glass lens or diffraction grating may be used to create a laser stripe. In an alternative embodiment, a galvo- driven mirror or other form of rastering may be used to create a laser stripe. In one embodiment, laser stripe 348 is to be panned across the target. In one embodiment, laser plane 348 may span the entire height of the target such that the entire target may be captured in one sweep across the target. In one embodiment, the spread of the laser stripe at the focal distance of the cameras in conjunction with the cameras field of view at that distance defines the size of target that can be captured.

In an alternative embodiment, the manifold retains four laser diodes that exhibit linearly diverse spacing. In this embodiment, a distance between each laser diode is different. A linear drive drives the manifold along a linear path to expose target to the light elements emitted by the lasers. The lasers may then be lensed as described in connection with the angular diverse embodiment above. Other than changing the diversity from angularly diversity with a rotational drive to linear diversity with a linear drive, the all remaining principles apply.

FIG. 4 is a block diagram of a system of one embodiment of the invention. Camera 132 is shown positioned within image capture region 108 of scanner 100. A field of view 410 of camera 132 is shown directed towards object 124 on turntable 114. As previously noted, camera 132 may capture an image of target 124 having an area of 5.1" x 3.8" inches or fewer at a distance of seven inches without resolution of 0.005". In an alternative embodiment, the camera may capture target 124 fitting within a 10.1" x 13.5" area at eighteen inches from the scanner with a resolution of 0.012". A second camera 134, is further included within image capture region 108. Camera 134 may have a field of view having a focal zone overlapping a focal zone of camera 132. A light pattern element 412 from projection unit 130 positioned in projection region 106 is shown intersecting a pixel focal line 414 at the surface of object 124.

Scanner 100 is coupled to a host node 404. This coupling may be by a bus 402 such as the Universal Serial Bus (USB)₇ IEEE 1394 bus, or any other suitable data transfer system. It is also within the scope and contemplation of the invention for scanner 100 to communicate with host node 404 via a wireless connection. Host node 404 may be a personal computer (PC), a work station, an internet appliance, or any other device that provides sufficient intelligence and processing power to render images from the data obtained by the ISA. In one embodiment, at least a portion of power supplied to scanner 100 may come from a connection to host node 404. Power may further be supplied to scanner 100, such as for example to run fixture light sources 200, 202, from a rechargeable lithium hydride battery. In one embodiment, scanner 100 may capture three-dimensional measurement data using laser triangulation. Alternatively, scanner 100 may capture three-dimensional measurement data using time of flight, stereoscopy or interfereometry. These other well known techniques are suitable to be embodied in a form factor as described above. In an alternative embodiment, scanner 100 may capture image data and then forward it to host node 404 for rendering. In this aspect, the processing on scanner 100 may be limited, permitting lower cost construction.

FIG. 5 is a perspective view of one embodiment of turntable 114 of FIG. 1 having a fixture 500 for supporting target object 124 during image capture. Fixture 500 is coupled to a top surface of plate 120. In one embodiment, fixture 500 may be a bar 502 extending vertically from the top surface of plate 120. Bar 502 may be secured to a center of plate 120 on one end by any conventional securing mechanism, including but not limited to, those previously discussed. Bar 502 may be of any material capable of supporting object 124 above plate 120, including but not limited to, a plastic or metal. Bar 502 may be dimensioned such that bar 502 may be inserted through object 124 so as not to obstruct a view of the object 124 sides. Alternatively, bar 502 may be a pair of bars dimensioned to support object 124 within a space between each bar without piercing object 124. In other embodiments, bar 502 may be dimensioned such that object 124 may be supported on an end of bar 502 opposite the end connected to plate 120. During scanner 100 operation, the projection unit is panned across object 124, plate 120 is then rotated and the projection unit makes another pass across object 124, this process is repeated until data from each side of object 124 is captured. With this data and knowledge of the position of plate 120 and where turntable 114 is located with respect to scanner 100, the data may be integrated to form a three-dimensional image of object 124 within a single operation.

FIG. 6 is a perspective view of one embodiment of the turntable of FIG. 2 having a fixture 600 for holding a target object 124. Fixture 600 is coupled to a top surface of plate 120 and may provide an additional axis to allow for viewing of a top and bottom of object 124 as well as the sides. In this aspect, fixture 600 may have a set of legs 602 extending vertically from plate 120. Legs 602 may be secured to plate 120 by any conventional securing mechanism, including but not limited to, those previously discussed. Another end of legs 602 may be coupled to a structure 604 designed to turn object 124 ninety degrees from an upright position and hold object 124 above plate 120 on its side. In one embodiment, structure 604 may be a bar 604 rotatably coupled at each end to legs 602. Bar 604 may be inserted through object 124 and then secured to legs 602 at each end. Alternatively, bar 604 may be a pair of bars dimensioned to support object 124 within a space between each bar without piercing object 124. A motor assembly (not shown) may be coupled to turntable 114 to drive rotation of bar 604. In this aspect, during operation of turntable 114, bar 604 rotates object 124 on its side to allow for capture of each side of object 124 within the field of view. In addition, while bar 604 is rotating, plate 120 rotates object 124 from end to end allowing for capture of each end of object 124 within the field of view. Thus, fixture 600 allows the top and bottom as well as the sides of object 124 to be captured by scanner 100. The captured data is then processed in a manner similar to that described with respect to fixture 50O₇ however, taking into account dimensions of the object top and bottom. In this aspect, a full three-dimensional image may be captured within a single operation. Moreover, since scanner 100 is able to capture all sides of object 124, the amount of work performed by scanner 100 in determining surface dimensions is reduced since the software is no longer required to fill in the missing dimensions. It is further within the scope and contemplation of the invention to provide a fixture or any number of fixtures on turntable 114 to facilitate capture of multiple sides of a target object.

Returning to FIG. 4, in one embodiment a location of points on a surface of three-dimensional target 124 may measured by triangulation. Although in embodiments of the invention, at least two laser planes are considered in calculating each point on the surface of target object 124, the instant description will describe triangulation with respect to a single laser plane for simplicity. In this aspect, laser plane 412 extends from a laser diode of projection unit 130 towards target object 124. A focal line 414 of a pixel of camera 132 is shown intersecting laser plane 412 at a point 416 on the object surface. As previously discussed, a distance between each projection unit and camera, illustrated as line 418, is known, thus from this information a distance between laser plane 412 and the pixel may be determined. A triangle is therefore defined by pixel focal line 414, laser plane 412 and distance line 418 between laser plane 412 and pixel focal line 414. Information obtained by the quadrature sensor may be used to determine an angle formed between the distance line and laser plane 412. Moreover, since camera 132 is maintained in fixed relation to projection unit 130, an angle formed between distance line 418 and focal line 414 of the pixel may be accurately determined. Thus, since two angles and distance are known, triangulation may be used to measure the location of point 416 on the object surface. This process may then be repeated for each point on the object surface. Alternatively, the scanner may capture three-dimensional measurement data by time of flight, stereoscopy or interfereometry. The points may then be integrated to form an image of the three-dimensional object.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the invention.

In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense

Claims

CLAIMSWe claim:

1. A system comprising: a scanner capable of capturing three dimensional measurement data about a target surface, the scanner including a housing retaining an image sensing array and a light source; wherein the scanner can capture an area of the target surface spanning at least two square inches in a single capture field; and wherein a bounding box circumscribing a projected footprint of the housing on a work surface at any time during operation has an area of no more than sixty-five square inches.

2. The system of Claim 1 wherein during operation no motion of any part of the scanners occurs outside an original volume of the scanner.

3. The system of Claim 1 further comprising: a texture light source coupled to the housing residing within the bounding box.

4. The system of Claim 1 wherein the light source is a laser further comprising: a drive assembly within the housing to move the laser to move a beam emitted by the laser.

5. The system of Claim 1 further comprising: an additional structure coupled to the housing that permits other activity of a user in the projected footprint on the work surface occupied by a non-overlapping portion of the additional structure.

6. The system of Claim 1 further comprising: at least one additional ISA coupled to the housing and having a focal zone overlapping a focal zone of the ISA.

7. The system of Claim 1 further comprising: a positioner discrete from the housing.

8. The system of Claim 7 further comprising: a fixture coupled to the turntable to hold an object during scanning.

9. The system of Claim 1 further comprising: a host computer coupled to the scanner.

10. The system of Claim 9 wherein at least a portion of power supplied to the scanner comes from a connection to the host.

11. The system of Claim 1 wherein the scanner captures the three dimensional measurement data using one of: laser triangulation, time of flight, stereoscopy or interfereometry.

12. A system comprising: a scanner capable of capturing three dimensional measurement data about a target surface, the scanner including a housing retaining an image sensing array and a light source wherein the scanner can capture an area of the target surface spanning at least two square inches in a single capture field; and a positioner capable of actively reorienting an object having the target surface wherein a first bounding box circumscribing the housing, and a second bounding box circumscribing the positioner, have an aggregate projected footprint area on a work surface, at any time during operation, of no more than ninety square inches.

13. An apparatus comprising: a scanner capable of capturing three dimensional measurement data about a target surface, the scanner including a housing retaining an image sensing array and a measurement light source; an integrated texture light source that has at least two points of emission that are separated by at least five inches; wherein a bounding box circumscribing a projected footprint of the housing on a work surface at any time during operation has an area of no more than sixty-five square inches.

14. The apparatus of Claim 13 wherein a same image sensing array is used to capture both texture and three dimensional measurement data.