Patents Assigned to Sentex Systems, Inc.
  • Patent number: 5475741
    Abstract: This system is for use by a visitor to a facility that has multiple occupants, public-subscriber or other phone service, and an individual phone outlet at each occupant's part of the facility. A microphone and speaker are provided so that a visitor seeking access can speak with an occupant. A communication circuit carries signals between (1) the mike and speaker and (2) the phone service--to enable the conversation through an individual phone outlet. Manual controls, preferably including a standard phone keypad, are positioned for use by the visitor. An electronic memory holds directory information, particularly including occupant names and corresponding dial-up codes. An LCD, behind a protective window, shows the visitor the directory data. Names and other directory data can be fed into the memory remotely, preferably through either: ordinary phone connections using standard DTMF signals--with automated confirmation of input data by a voice-synthesis chip--or a modem.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: December 12, 1995
    Assignee: Sentex Systems, Inc.
    Inventors: William R. Davis, Dennis W. Mowers, Richard P. Greenthal, Paul Szymanski, Ronald A. Wray, Richard A. Davidson
  • Patent number: 5416495
    Abstract: A liquid-crystal display preferably eighteen lines of forty characters each, is mounted in a case. The temperature of the display medium is held within operating limits for the display--notwithstanding ambient temperature and humidity variations over generally normal ranges for at least the temperate zones, and even if the display unit receives direct sunlight. The unit works outdoors, at temperatures to at least 46.degree. C. (115.degree. F.) as well as in buildings with no temperature control. This is accomplished by use of a shading hood, and a window (preferably unperforated polycarbonate, curved, upward-and-outward-concave, and cylindrical-segment) that reflects to a viewer only light from the hood underside. No ventilating fan, plenum or other ventilating opening is needed. A circuit-board-mounted temperature sensor controls the contrast-adjusting voltage of the display--using data in a digital-memory "look up" table. A heater is preferably provided, also temperature-controlled.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: May 16, 1995
    Assignee: Sentex Systems, Inc.
    Inventors: William R. Davis, John F. Ahlstrom, Richard P. Greenthal