Patents by Inventor Steven W Birch

Steven W Birch 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).

  • Patent number: 6858912
    Abstract: A photodetector circuit incorporates an avalanche photodiode (APD) 300 produced by epitaxy on a CMOS substrate 302 with implanted n-well 304 and p-well 306. The n-well 304 has an implanted p+ guard ring 310 delimiting the APD 300. Within the guard ring 310 is an implanted n+ APD layer 312 upon which is deposited an epitaxial p+ APD layer 314, these layers forming the APD 300. The APD may be incorporated in an amplifier circuit 50 providing feedback to maintain constant bias voltage, and may include an SiGe absorption region to provide extended long wavelength response or lower avalanche voltage. Non-avalanche photodiodes may also be used.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: February 22, 2005
    Assignee: QinetiQ Limited
    Inventors: Gillian F Marshall, David J Robbins, Wang Y Leong, Steven W Birch
  • Publication number: 20020024058
    Abstract: A photodetector circuit incorporates an avalanche photodiode (APD) 300 produced by epitaxy on a CMOS substrate 302 with implanted n-well 304 and p-well 306. The n-well 304 has an implanted p+ guard ring 310 delimiting the APD 300. Within the guard ring 310 is an implanted n+ APD layer 312 upon which is deposited an epitaxial p+ APD layer 314, these layers forming the APD 300. The APD may be incorporated in an amplifier circuit 50 providing feedback to maintain constant bias voltage, and may include an SiGe absorption region to provide extended long wavelength response or lower avalanche voltage. Non-avalanche photodiodes may also be used.
    Type: Application
    Filed: August 8, 2001
    Publication date: February 28, 2002
    Inventors: Gillian F. Marshall, David J. Robbins, Wang Y. Leong, Steven W. Birch
  • Patent number: 4915317
    Abstract: A winding apparatus for web material with severing device comprising a pair of power driven endless cutter chains wherein the tension of the cutter chains is adjusted during operation of the winding apparatus and thereby avoids the need for periodic manual adjustment and the problems attendant thereto. The device for adjusting the tension comprises a force applying fluid cylinder to move one of the sprockets carrying each chain to a position which increases the tension. A cooperating latch device serves to secure the sprocket in any adjusted position.
    Type: Grant
    Filed: February 15, 1989
    Date of Patent: April 10, 1990
    Assignee: Birch Brothers Southern
    Inventor: Steven W. Birch
  • Patent number: 4475696
    Abstract: A roll of web material is initially supported at a first winding station and in engagement with spaced-apart first and second rolls which are driven at different peripheral speeds to provide a "tight" initial wind. The roll of web material is then transferred to a second winding station and supported in engagement with first and second winding rolls with the second winding roll being movable away from the first winding roll and further away from the first winding station as the size of the roll of web material increases so that large or jumbo size rolls may be wound on the apparatus.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: October 9, 1984
    Assignee: Birch Brothers Southern Incorporated
    Inventors: Steven W. Birch, George E. Barnes
  • Patent number: 4194659
    Abstract: An apparatus and method in which lengths of web material joined by widthwise seams are guided along a path of travel and between a pair of rolls arranged to form a nip. In accordance with this invention, a plurality of seam detectors are provided and the rolls are separated in response to and in predetermined relation with sensing of a seam by all of the detectors, in order to avoid damage to the rolls or to the seam portion of the fabric during handling.
    Type: Grant
    Filed: May 19, 1978
    Date of Patent: March 25, 1980
    Assignee: Birch Brothers Southern, Incorporated
    Inventor: Steven W. Birch
  • Patent number: 4128212
    Abstract: An apparatus and method in which lengths of web material joined by widthwise seams are guided along a path of travel adjacent a shear, either for decorative shearing or for roll winding. In the instance of decorative shearing, the web material surface is sheared to produce a particular desired effect, such as velour fabric. In winding, web material is wound into a roll of up to a first diameter at a starting winding position and then transferred to a second winding position at which winding continues to a larger diameter. The web material is controllably sheared or severed between the starting and second winding positions upon the material roll being wound at the second position reaching a desired diameter. In accordance with this invention, a plurality of seam detectors are provided and shear movement occurs in response to and in predetermined relation with sensing of a seam by all of the detectors, in order to avoid severing a seam in decorative shearing or to sever through a seam in winding.
    Type: Grant
    Filed: June 23, 1977
    Date of Patent: December 5, 1978
    Assignee: Birch Brothers Southern, Inc.
    Inventor: Steven W. Birch