US4230950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-optic smoke detector
Assignee: Honeywell Inc
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Filing: 1979-05-16
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Granted: 1980-10-28
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Expires: 1999-05-16
Abstract
Abstract An electro-optic smoke detector is described which has an improved smoke chamber and detector construction to enhance the detector sensitivity in general and its response to small smoke particles in particular.
Inventors
- 👤 John A. Forss
- 👤 Tzuo-Chang Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:25
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/10; G08B17/103; G08B17/107; G08B17/11; G08B17/113
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
Optical smoke detector apparatus comprising: a smoke sensing chamber having air inlet and outlet means; an optical sensor in said chamber having a face comprising a light receiving portion and a light reflecting portion, said light receiving portion being of a relatively large area with respect to said light reflecting portion; light source means in said apparatus; means directing the light from said source substantially onto said light reflecting portion and minimally onto said light receiving portion, whereby the light directed on said light reflecting portion is reflected generally back towards said source without falling on said light receiving portion; and whereby in the presence of smoke in said chamber light is scattered thereby, and falls on said light receiving portion to indicate the presence of said smoke.
Claim 2
Dependent Claim
128 words
Optical smoke detector apparatus comprising: a smoke sensing chamber having air inlet and outlet means; an optical sensor in said chamber having a face comprising a light receiving portion and a light reflecting portion, said light receiving portion being of a relatively large area with respect to said light reflecting portion; light source means in said apparatus; means directing the light from said source substantially onto said light reflecting portion and minimally onto said light receiving portion, whereby the light directed on said light reflecting portion is reflected generally back towards said source without falling on said light receiving portion; and whereby in the presence of smoke in said chamber light is scattered thereby, and falls on said light receiving portion to indicate the presence of said smoke.
Claim 3
Dependent Claim
35 words
The apparatus in accordance with claim 1 wherein, said optical sensor face is substantially planar, with said light reflecting portion taking the form of a small mirror in the middle of said light receiving portion.
Claim 4
Dependent Claim
28 words
The apparatus in accordance with claim 1 wherein, said light source means is an infrared source and said optical sensor light receiving portion is sensitive to the infrared.
Claim 5
Dependent Claim
17 words
The apparatus in accordance with claim 1 wherein, said means directing the light is a focussing lens.
Claim 6
Dependent Claim
118 words
An improved smoke sensing chamber for an optical smoke detector apparatus comprising: a smoke sensing chamber; light source means in said apparatus; mirror means in said chamber; light detector means surrounding said mirror means in said chamber; means focussing the light from said source onto said mirror means and not onto said surrounding light detector means, whereby the light directed on said mirror means is reflected generally back toward said source without falling on said light detector means; and whereby in the presence of smoke in said chamber the focussed light and the reflected light is scattered by the smoke particles and the scattered light falls on the light detector means to indicate the presence of said smoke.
Claim 7
Dependent Claim
118 words
An improved smoke sensing chamber for an optical smoke detector apparatus comprising: a smoke sensing chamber; light source means in said apparatus; mirror means in said chamber; light detector means surrounding said mirror means in said chamber; means focussing the light from said source onto said mirror means and not onto said surrounding light detector means, whereby the light directed on said mirror means is reflected generally back toward said source without falling on said light detector means; and whereby in the presence of smoke in said chamber the focussed light and the reflected light is scattered by the smoke particles and the scattered light falls on the light detector means to indicate the presence of said smoke.
Claim 8
Dependent Claim
16 words
The apparatus in accordance with claim 5 wherein, said light source means is an infrared source.
Claim 9
Dependent Claim
19 words
The apparatus in accordance with claim 6 wherein, said infrared source is a gallium arsenide light emitting diode (LED).
Claim 10
Dependent Claim
18 words
The apparatus in accordance with claim 6 wherein, said light detector means is sensitive to the infrared source.
References Cited (Backward Citations)
US3524707A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |