Patents by Inventor Donald W. Schaeffer

Donald W. Schaeffer 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: 4745438
    Abstract: A fade-out system for a copier with a document feeder, for preventing the undesired development of areas of the photosensitive imaging surface relative to the desired latent images of the document with a variable magnification optical imaging system, preventing "show around" copy defects from the document feeder, where the document feeder transports the document sheets in a document path onto and over the copying platen of the copier. An array of plural document sensors is positioned in the document feeder for measuring both the length and width of the document sheets being transported onto the copying platen, and the fade-out system connects with and is controlled by both the array of plural document sensors and the magnification setting of the optical imaging system for preventing development of any areas of the photosensitive imaging surface outside of the latent images of the documents irrespective of the size of the document sheets or the magnification setting.
    Type: Grant
    Filed: September 16, 1986
    Date of Patent: May 17, 1988
    Assignee: Xerox Corporation
    Inventors: Thomas Acquaviva, Donald W. Schaeffer
  • Patent number: 4468114
    Abstract: In recirculatively precollatively copying a set of plural original documents onto both sides of copy sheets to produce a desired plural number precollated duplex copy sheet sets, by normally copying the documents only once in each copying circulation of the document set onto one side of copy sheets to form a duplexing buffer and copying other documents onto the opposite sides of the buffer copies to form duplex precollated copies, the improvement comprising: counting the number of documents in the document set and determining that the number of documents is only two or three, and in response to the determination, automatically switching the mode of copying of the documents to a higher productivity two or three document set mode in which plural identical consecutive copies are first made from only one document (the first document page) by halting the first copying circulation of the document set to copy only the one document, and forming the buffer from these plural identical copies and then skipping the copyi
    Type: Grant
    Filed: December 10, 1982
    Date of Patent: August 28, 1984
    Assignee: Xerox Corporation
    Inventors: Susan J. Pels, Donald W. Schaeffer