Patents by Inventor David A. Grafton
David A. Grafton has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6181482Abstract: An anamorphic lens attachment to be used in conjunction with a basic lens. The attachment provides a variable anamorphic ratio. The attachment comprises a first lens group having positive refractive power in a first direction, a second lens group having negative refractive power in the first direction, and a third lens group having positive refractive power in the first direction. The second lens group is movably located between the first lens group and the basic lens. The third lens group is located between the second lens group and the basic lens at a fixed distance from the first lens group. The lens groups of the attachment have neutral refractive power in a second direction substantially perpendicular to the first direction.Type: GrantFiled: September 8, 1999Date of Patent: January 30, 2001Assignee: News America IncorporatedInventor: David A. Grafton
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Patent number: 5512949Abstract: A system for eliminating differential scan line bow from raster output scanners aligns at least the chief exit ray of each scanning light beam with the system axis. By aligning the chief exit rays to be essentially parallel to the system axis, the overall bow is reduced, and the bow of different scan lines is essentially identical. Thus, bowed scan lines from different stations in a multi-station printer, or from different passes in a multi-pass printer are generally identical and aligned.Type: GrantFiled: December 29, 1993Date of Patent: April 30, 1996Assignee: Xerox CorporationInventors: Tibor Fisli, David A. Grafton
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Patent number: 4422181Abstract: A bi-directional fibre-optic coupler providing about 70 dB to about 100 dB isolation from near end transmitter radiation in a system that transmits signals in opposite directions over a single fibre and thereby provides a low-loss coupler having operational characteristics to handle reception and transmission with sufficiently low value of crosstalk.Type: GrantFiled: August 26, 1980Date of Patent: December 20, 1983Assignee: The United States of America as represented by the Secretary of the ArmyInventors: David A. Grafton, Eric B. Hochberg, Ronald E. Purkis
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Patent number: 4397521Abstract: A raster scanner with laser for generating a scanning beam and compact folded optical system for transmitting the beam to the object to be scanned. The optical system includes a first mirror for guiding the laser beam forward along a downwardly inclined slope to the modulator, a second mirror below the modulator for intercepting the beam from the modulator and folding the intercepted beam to guide the beam backwards along a horizontal plane to a third mirror which folds the beam and guides the beam forward along an upwardly inclined slope against the mirrored facets of a rotating polygon, the polygon scanning the beam through a preset scan arc and returning the beam via a focusing lens to the third mirror, the third mirror folding the scan beam and guiding the scan beam forward, and a fourth mirror for intercepting the scan beam and guiding the beam to the object to be scanned.Type: GrantFiled: September 29, 1980Date of Patent: August 9, 1983Assignee: Xerox CorporationInventors: Ronald L. Antos, Harry P. Brueggemann, David A. Grafton
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Patent number: 4230394Abstract: An all mirror facet tracking system including first and second spherical mirrors. Both of the mirrors can be located along the same system axis on opposite sides of a rotating multi-faceted polygon which has its axis of rotation on the system axis. To reduce coma, the spherical mirrors are located along orthogonal system axes and a flat folding mirror is provided between the two spherical mirrors to reduce the angle of incidence of the chief ray with the second spherical mirror.Type: GrantFiled: April 2, 1979Date of Patent: October 28, 1980Assignee: Xerox CorporationInventors: Harry P. Brueggemann, David A. Grafton
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Patent number: 4174174Abstract: Apparatus for automatically producing microfiche from microfilm and microfilm from microfilm in different formats or reductions. In particular, a reel of microfilm having frames of sequentially recorded photographic images thereon is loaded into a microfilm film transport and the microfilm is automatically stepped, frame by frame, past a film-illuminating device. The frames on the microfilm are reduced in size by a reducing lens and imaged at a plane within a microfilm recorder device. The microfilm recorder device is automatically controlled in a manner whereby film contained therein is movable in two dimensions in a plane which is coplanar with the image focal plane. The movement of the film is such that a plurality of frames or microimages arranged in columns and rows and corresponding to the microfilm frames being illuminated are arranged on the film in a preselected microfiche format.Type: GrantFiled: March 15, 1977Date of Patent: November 13, 1979Assignee: Xerox CorporationInventors: Robert K. Hunter, Jr., David A. Grafton, Joseph Lander, Lauren V. Merritt, Donald E. Stewart, Donald H. Wolpert
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Patent number: 4070089Abstract: An intensity modulated laser beam is directed to a rotating scanner having a plurality of facets which scans the beam across the surface of a movable mirror in a first scan direction. The mirror is movable in a manner whereby the beam is deflected in a second scan direction. The light reflected from the movable mirror is directed through a focusing lens onto a movable cylinder lens located adjacent the platen which is movable in a direction corresponding to the second scan direction, thereby providing two-dimensional scanning of a document. In one embodiment, the movable mirror and the movable cylinder lens are driven by a single motor and are coupled together in the manner whereby the movement thereof is mechanically interlocked thereby providing perfect tracking of the scanned laser beam within the clear aperture of the cylinder lens. In a second embodiment, the movable mirror and the movable cylinder lens may be independently driven and interlocked electronically.Type: GrantFiled: July 1, 1976Date of Patent: January 24, 1978Assignee: Xerox CorporationInventor: David A. Grafton
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Patent number: 4006299Abstract: A scanning system is provided which uses directed light from a scanning element, which directed light is reflected from a curved reflective surface for scanning across a medium with a planar object surface. The scanning element includes a planar reflective facet, such as the planar mirrored surface of a galvanometer, which scans the light across the curved reflective surface in a direction normal to its axis of curvature. To provide a linear focal line, the planar surface is tilted from its optical axis by a first angle and is off-set for rotation about an axis at a second angle from an optical axis orthogonal to the optical axis of the curved surface.Type: GrantFiled: December 11, 1974Date of Patent: February 1, 1977Assignee: Xerox CorporationInventor: David A. Grafton
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Patent number: 3946150Abstract: A flux scanner which is comprised of a rotating polygon for scanning a beam of radiated flux transverse a photoreceptive medium. In the beam path between the flux source and the polygon, an astigmatic-beam expander lens is employed to focus the flux distributions to a spot at an image plane. The astigmatic lens is configured so as to produce a very narrow beam of flux to control the size of the spot in a direction orthogonal to the transverse direction, without any loss of efficiency. Between the photoreceptive medium and the polygon, a cylindrical lens and linear optical elements are positioned to focus the beam to control the size of the spot along the transverse direction. The transverse direction is designated optically as the tangential plane; whereas the direction orthogonal to the transverse direction is designated optically as the sagittal plane.Type: GrantFiled: December 20, 1973Date of Patent: March 23, 1976Assignee: Xerox CorporationInventor: David Grafton