Claims
- 1. A system for detecting the presence of a human in a compartment of a vehicle comprising:a thermal sensor assembly mounted in the compartment of the vehicle and adapted to sense a thermal characteristic of the compartment, said thermal sensor assembly comprising a pyroelectric sensor and a control coupled to said pyroelectric sensor, said control generating a signal as a function of a change in the thermal characteristic of the compartment as sensed by the pyroelectric sensor, wherein a filter element comprising a multiple film interference filter is disposed in said thermal sensor assembly in front of said pyroelectric sensor, said filter element adapted to filter radiation of a particular wavelength incident on said thermal sensor assembly, wherein said filter element comprises at least one of filter material selected from the group consisting of: Ge, Si, ZnS, CdS and Polyolefin, and wherein said filter element principally transmits radiation in the 8-14 micron wavelength range, and wherein said control comprises an electronic band-pass filter, said electronic band-pass filter passing frequencies greater than 0.01 Hz and less than 100 Hz.
- 2. A system according to claim 1, wherein said filter material comprises Ge.
- 3. A system according to claim 1, wherein said filter material comprises Si.
- 4. A system according to claim 1, wherein said filter material comprises ZnS.
- 5. A system according to claim 1, wherein said filter material comprises CdS.
- 6. A system according to claim 1, wherein said filter material comprises Polyolefin.
- 7. A system according to claim 1, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz and less than 10 Hz.
- 8. A system according to claim 1, wherein said electronic band-pass filter passes frequencies greater than 0.5 Hz and less than 10 Hz.
- 9. A system according to claim 1, wherein said electronic band-pass filter passes frequencies greater than 1 Hz and less than 5 Hz.
Parent Case Info
This application is a continuation of application Ser. No. 08/901,929, filed Jul. 29, 1997, now U.S. Pat. No. 6,166,625, which is a continuation-in-part of application Ser. No. 08/720,237, filed on Sep. 26, 1996, now abandoned, and entitled Automotive Pyroelectric Intrusion Detection.
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Continuations (1)
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Number |
Date |
Country |
Parent |
08/901929 |
Jul 1997 |
US |
Child |
09/663998 |
|
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08/720237 |
Sep 1996 |
US |
Child |
08/901929 |
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US |