The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 1993
Filed:
Mar. 13, 1991
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A GPS receiver includes a power supplying status detector for deriving a power-on or power-off signal by detecting a power supplying status of the GPS receiver, a clock for measuring time, a memory controller for controlling a nonvolatile memory upon receiving the power-off signal to store a time measured by the clock when the power is turned off or a time when the last ephemeris data is obtained and the last ephemeris data, and a position calculating circuitry for calculating the position of the user station upon receiving the power-on signal. A time duration is calculated from the time measured by the clock and the time stored in the nonvolatile memory. If it is determined that the measured time duration is shorter than a predetermined period of time, the positioning is performed based on the respective ephemeris data stored in the nonvolatile memory, whereas if it is determined that the measured time duration is no less than the predetermined period of time, the positioning is performed based on ephemeris data newly collected from the respective GPS satellites.