United States Patent [19] [ii] Patent Number: 4,839,639
Sato et al. [45] Date of Patent: Jun. 13,1989
[54] PAGING RECEIVER HAVING BATTERY SAVING CIRCUIT
[75] Inventors: Toshifumi Sato; Takashi Oyagi, both of Tokyo, Japan
[73] Assignee: NEC Corporation, Tokyo, Japan
{21] Appl. No.: 2,329
[22] Filed: Jan. 12,1987
[30] Foreign Application Priority Data
Jan. 10, 1986 [JP] Japan 61-1974
[51] Int. CI.4 H04Q 7/00
[52] U.S. a 340/825.44; 455/343;
371/47
[58] Field of Search 340/825.44, 825.47,
340/825.48, 311.1; 455/31, 38, 228, 343;
379/56, 57; 371/47
[56] References Cited
U.S. PATENT DOCUMENTS
3,769,593 10/1973 Williams 455/343
4,419,765 12/1983 Wycoffetal 340/825.48
4,506,262 3/1985 Vance et al 340/825.44
4,523,332 6/1985 Mori 455/228
4,652,875 3/1987 Waki 340/825.44
4,663,623 5/1987 Lax et al 455/343
FOREIGN PATENT DOCUMENTS
2144565 3/1985 United Kingdom 340/825.44
Primary Examiner—John W. Caldwell, Sr.
Assistant Examiner—Edwin C. Holloway, III
Attorney, Agent, or Firm—Sughrue, Mion, Zinn,
Macpeak & Seas
[57] ABSTRACT
A paging receiver includes an improved battery saving circuit which reduces battery usage by powering the radio section and the waveform shaping circuitry only during intervals which include address codewords specific to the given receiver group. Power is not supplied during intervals containing synchronization code signals other than during the first such interval directly following the preamble code. Upon detecting a preamble code during said intervals, power is supplied continuously for a time period sufficient to encompass the synchronization code interval.
8 Claims, 8 Drawing Sheets
