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US006288647B1
(12) United States Patent ao) Patent No.: us 6,288,647 Bi
Yamano (45) Date of Patent: Sep. 11,2001
(54) PHOTOELECTRIC SMOKE DETECTOR, AND SMOKE DETECTION SECTION ASSEMBLY
(75) Inventor: Naoto Yamano, Tokyo (JP)
(73) Assignee: Hochiki Corporation, Tokyo (JP)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/699,420
(22) Filed: Oct. 31, 2000
(30) Foreign Application Priority Data
Nov. 1, 1999 (JP) 11-310585
(51) Int. C I. G08B 17 10
(52) U.S. CI 340/630; 340/628; 250/574
(58) Field of Search 340/628, 630;
253/573, 574
(56) References Cited
U.S. PATENT DOCUMENTS
4,851,819 * 7/1989 Kawai et al 340/630
A photoelectric smoke detector includes a smoke detecting section defining a smoke detecting space, a light emission section holder having a light-emission element disposed in the smoke detecting section, and a light receiving section holder having a light-receiving element disposed in the smoke detecting section. The light-receiving element receives light which has been emitted Irom the lightemission element and is scattered by smoke flowing in the smoke detecting space. A hybrid circuit board has an integrated circuit mounted thereon and is housed in the light receiving section holder. The integrated circuit including the light-receiving element and at least a received-light signal amplifying circuit. The hybrid circuit board is arranged so that the light-receiving surface of the light-receiving element is directed toward the smoke detecting space.
44 Claims, 23 Drawing Sheets
