...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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AbstractIn a battery powered radio paging receiver, a battery saving method extends battery life and prevents the loss of messages stored in volatile random access memory. Upon receipt of a message, a plurality of alerting devices (vibrators, LCD back-lights, LED's and audio alert tone generators) are sequentially activated. Before each device is activated, however, the battery voltage is checked to determine if sufficient charge remains to power the alerting device without dropping the battery voltage below the minimum requirement for retaining information in the memory. If an alerting device is activated, the battery voltage is repeatedly checked and if it drops below a threshold level, the device is deactivated. If the alerting device is an escalating volume audio alert tone generator and the battery voltage is below a threshold voltage, the volume of the generator is restricted to its lower volume range. The received message is also checked to determine if it has a priority status. If the message is a priority message, all alerting devices are activated, regardless of the battery voltage. | InventorApplicationNo. 06/924375 filed on 10/29/1986US Classes:340/7.37, Control based upon available power340/636.1, Battery340/636.15, By voltage340/7.58, Alert455/343.5Battery saving based on detected power source levelField of Search340/635, Condition of electrical apparatus340/660, Voltage340/661, Comparison340/663UndervoltageExaminersPrimary: Caldwell, Sr., John W.Assistant: Holloway, III, Edwin C. Attorney, Agent or FirmUS Patent References3800207, 4075699, Power monitoring and load shedding systemIssued on: 02/21/1978 Inventor: Schneider , et al.4160240, Binary digital pager having an eight function code read-out Issued on: 07/03/1979 Inventor: Partipilo4237448, Pager with escalating audio alert signal level Issued on: 12/02/1980 Inventor: Weinberg4412217, Pager with visible display indicating status of memory Issued on: 10/25/1983 Inventor: Willard , et al.4438433, Multiaddress pager with a call storage and priority paging option Issued on: 03/20/1984 Inventor: Smoot , et al.4488115, Low battery voltage indicator circuit for a metal detector Issued on: 12/11/1984 Inventor: Podhrasky4509201, Wireless telephone apparatus with protection against power loss Issued on: 04/02/1985 Inventor: Sekigawa , et al.4644350, Pager with automatically illuminated display Issued on: 02/17/1987 Inventor: Ishii4660027Reduced power consumption low battery alert device Issued on: 04/21/1987 Inventor: Davis International ClassesG08B 3/10 (20060101)G08B 3/00 (20060101) G08B 29/18 (20060101) G08B 29/00 (20060101) H04B 1/16 (20060101) H04Q 7/18 (20060101) |