US4682030A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infrared radiation detector with integral fresnel lens window
Assignee: US Philips Corp
•
Filing: 1985-08-19
•
Granted: 1987-07-21
•
Expires: 2005-08-19
Abstract
Abstract An infrared radiation detector comprises a pyroelectric detector element in a hermetically sealed housing. The housing comprises a base and cover with an aperture. A Fresnel lens, for example made of polyethylene transmissive in the 8-14 μm wavelength range, is fastened over the aperture on the inside of the cover for condensing the radiation to be detected onto the detector element. In one example the Fresnel lens is held against a flange surrounding the aperture by a press-fit ring. Alternatively, the Fresnel lens is glued to a silicon window which in turn is fastened to the flange surrounding the aperture. The Fresnel lens thus forms an integral part of the detector housing avoiding the need for external mirrors or lenses.
Inventors
- 👤 Michael A. Rose
- 👤 Martin Renals
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:40
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/04; G01J5/041; G01J5/045; G01J5/046; G01J5/08; G01J5/0801; G01J5/0806; G01J5/0875; G01J5/10; G01J5/34; Y; Y10; Y10S; Y10S250/00; Y10S250/01
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
54 words
An infrared radiation detector comprising: a hermetically sealed housing; and a pyroelectric detector element arranged in the hermetically sealed housing; characterized in that the hermetically sealed housing comprises: a canister having an aperture therein; and a Fresnel lens arranged in the hermetically sealed housing over the aperture to condense radiation onto the detector element.
Claim 2
Dependent Claim
54 words
An infrared radiation detector comprising: a hermetically sealed housing; and a pyroelectric detector element arranged in the hermetically sealed housing; characterized in that the hermetically sealed housing comprises: a canister having an aperture therein; and a Fresnel lens arranged in the hermetically sealed housing over the aperture to condense radiation onto the detector element.
Claim 3
Dependent Claim
26 words
An infrared radiation detector as claimed in claim 1, characterized in that the Fresnel lens comprises a central condensing portion and a peripheral noncondensing frame portion.
Claim 4
Dependent Claim
23 words
An infrared radiation detector as claimed in claim 2, characterized in that the condensing portion has a diameter not greater than 10 mm.
Claim 5
Dependent Claim
23 words
An infrared radiation detector as claimed in claim 3, characterized in that the condensing portion has a diameter approximately equal to 5 mm.
Claim 6
Dependent Claim
24 words
An infrared radiation detector as claimed in claim 1, characterized in that the Fresnel lens has a focal length not greater than 10 mm.
Claim 7
Dependent Claim
24 words
An infrared radiation detector as claimed in claim 5, characterized in that the Fresnel lens has a focal length approximately equal to 5 mm.
Claim 8
Dependent Claim
41 words
An infrared radiation detector as claimed in claim 1, characterized in that: the canister has a bore; the detector has an optical axis; and the bore and the lens have approximately equal cross-sectional shapes and sizes transverse to the optical axis.
Claim 9
Dependent Claim
39 words
An infrared radiation detector as claimed in claim 1, characterized in that: the canister has an inwardly extending flange arranged around the aperture; and the lens is held against the flange by an annular press-fit member inside the canister.
Claim 10
Dependent Claim
23 words
An infrared radiation detector as claimed in claim 8, characterized in that the annular member has a projection which bites into the lens.
Claim 11
Dependent Claim
32 words
An infrared radiation detector as claimed in claim 1, characterized in that the housing further comprises a window arranged in the canister over the aperture, the lens being fastened to the window.
Claim 12
Dependent Claim
40 words
An infrared radiation detector as claimed in claim 1, characterized in that: the canister has an inwardly extending flange arranged around the aperture; and the window is fastened to the flange and the Fresnel lens is fastened to the window.
Claim 13
Dependent Claim
22 words
An infrared radiation detector as claimed in claim 11, characterized in that the Fresnel lens is fastened to the window with adhesive.
Claim 14
Dependent Claim
35 words
An infrared radiation detector as claimed in claim 12, characterized in that the Fresnel lens is made of a plastic material which is transparent to infrared radiation in the 8 to 14 micron wavelength range.
Claim 15
Dependent Claim
19 words
An infrared radiation detector as claimed in claim 13, characterized in that the Fresnel lens is made of polyethylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |