Use of optical reflectance proximity detector for nuisance mitigation in smoke alarms

• US 8,754,775 B2
• Filed: 03/19/2010
• Issued: 06/17/2014
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Nest Labs Incorporated (Alphabet Inc.)
• Inventors: Holcombe, Wayne T.
• Primary Examiner(s): Lim, Steven
• Assistant Examiner(s): Yacob, Sisay
• Application Number:
  US12/727,983
• Publication Number:
  US 20100238036A1
• Time in Patent Office: 1,551 Days
• Field of Search: 340628-630, 340577-584, 340/587, 340/309.16, 340/527, 73/233.3, 73/233.5, 73/530.1, 250/554, 250/200, 356/441, 116/101, 116/216, 116/67.R
• US Class Current: 340/629
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 17/103 using a light emitting and receiving device
• CPC Class Codes: G08B 17/11 using an ionisation chamber for detecting smoke or gas
• CPC Class Codes: G08B 29/145 of fire detection circuits
• CPC Class Codes: G08B 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system
• CPC Class Codes: G08B 3/10 using electric transmission; using electromagnetic transmission

Abstract

A smoke alarm comprises smoke detection circuitry for detecting smoke and generating a detection signal responsive thereto. Proximity detection circuitry generates a proximity detection signal responsive to detection of an object within in a selected distance of the smoke alarm. Alarm generation circuitry generates an audible alarm responsive to the detection signal. The audible alarm may be deactivated for a predetermined period of time responsive to at least one proximity detection signal.

Claims

1. A smoke alarm, comprising:

smoke detection circuitry for detecting smoke and generating a smoke detection signal responsive thereto;

proximity detection circuitry for generating a proximity detection signal when the proximity detection circuitry detects a movement of an object within a selected distance of the smoke alarm; and

alarm generation circuitry for generating an audible alarm responsive to the smoke detection signal, wherein the audible alarm is temporarily deactivated when at least two proximity detection signals are generated within a predetermined period of time and while the smoke detection signal is received.

2. The smoke alarm of claim 1, further comprising:

battery charge test circuitry for determining a charge level of a battery associated with the smoke alarm; and

wherein the alarm generation circuitry generates a first audible indication when the charge level of the battery exceeds a predetermined level and generates a second audible indication when the charge level of the battery falls below the predetermined level.

3. The smoke alarm of claim 1, wherein the alarm generation circuitry generates the audible alarm at a first level responsive to a first proximity detection signal and generates the audible alarm at a second level responsive to a second proximity detection signal when the audible alarm is at the first level.

4. The smoke alarm of claim 1, wherein the smoke detection circuit comprises an optical detection circuit.

5. The smoke alarm of claim 1, wherein the smoke detection circuit comprises an ionization detection circuit.

6. A method for controlling operation of a smoke alarm, comprising:

detecting smoke with the smoke alarm;

generating an audible alarm responsive to detection of the smoke;

detecting movement of an object within a selected distance of the smoke alarm, wherein the movement is detected using a proximity detection circuit; and

temporarily deactivating the audible alarm when at least two movements of the object are detected within a predetermined period of time and within the selected distance of the smoke detector and while detecting the smoke.

7. The method of claim 6, further comprising:

reactivating the audible alarm after another predetermined period of time when the smoke is still detected by the smoke alarm.

8. The method of claim 6, further comprising:

detecting movement of the object within the selected distance when an audible alarm is not being generated;

determining a charge level of a battery associated with the smoke alarm responsive to the detected movement;

generating a first audible indication when the charge level of the battery exceeds a predetermined level; and

generating a second audible indication when the charge level of the battery falls below the predetermined level.

9. The method of claim 6, wherein the step of generating the audible alarm further includes:

generating the audible alarm at a first level responsive to a first detected movement of the object; and

generating the audible alarm at a second level responsive to a second detected movement when the audible alarm is at the first level.

10. A method for controlling operation of a smoke alarm, comprising:

detecting smoke with the smoke alarm;

generating an audible alarm responsive to detection of the smoke;

detecting movement of an object within a selected distance of the smoke alarm, wherein the movement is detected using a proximity detection circuit; and

controlling operation of the smoke alarm when at least two movements of the object are detected within a predetermined period of time and within the selected distance of the smoke alarm and while the smoke is detected.

11. The method of claim 10, wherein controlling operation of the smoke alarm further includes temporarily deactivating the audible alarm.

12. The method of claim 11, further comprising:

reactivating the audible alarm after another predetermined period of time when the smoke is still detected by the smoke alarm.

13. The method of claim 10, wherein controlling operation of the smoke detector further includes:

detecting movement of the object within the selected distance when an audible alarm is not being generated;

determining a charge level of a battery associated with the smoke alarm responsive to the detected movement;

generating a first audible indication when the charge level of the battery exceeds a predetermined level; and

generating a second audible indication when the charge level of the battery falls below the predetermined level.

14. The method of claim 10, wherein generating the audible alarm further includes:

generating the audible alarm at a first level responsive to a first detected movement of the object; and

generating the audible alarm at a second level responsive to a second detected movement when the audible alarm is at the first level.