Portable map reading system
Patent 4164822 Issued on August 21, 1979. Estimated Expiration Date: 
January 4, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 4, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1989803 1997157 2567561 3663921 InventorApplicationNo. 05/860860 filed on 01/04/1978US Classes:40/361, PHOTOGRAPHIC TRANSPARENCY VIEWER, E.G., X-RAY VIEWER40/902CIRCUIT CONTROL (FLASHING LIGHT, ETC.)ExaminersPrimary: Mancene, Louis G.Assistant: Contreras, Wenceslao J. Attorney, Agent or FirmInternational ClassG02B 27/02 (20060101)AbstractA portable map-display system for auto, boat and airplane uses and the like includes a plurality of translucent maps and a compact light box proportioned for back-lighting one map at a time. To prevent unshielded glare from the light-box and to assure proper orientation of maps on the light-box a series circuit arrangement turns off the light circuit in the box when a map is not properly in place over the light-box. The series circuit arrangement includes a conductive strip asymmetrically disposed on each map and a pair of electrodes on the light-box adapted for resiliently receiving the conductive strip of a map between them to close the circuit and turn on the light. | |
