ALARM DEVICE

• US 20100141436A1
• Filed: 12/02/2009
• Published: 06/10/2010
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Original Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Inventors: Watanabe, Toshimitsu, Masuyama, Makoto, Morita, Hidesato
• Granted Patent: US 8,305,209 B2
• Time in Patent Office: Days
• US Class Current: 340/539.220
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence

Abstract

Provided is an alarm device capable of performing transmission and reception reliably while suppressing an amount of current consumption. An alarm device (100) includes: a fire detection circuit (7); a control circuit (1); and a transmitting/receiving circuit (5). The transmitting/receiving circuit (5) transmits the status signal to the another alarm device (100) with a transmission pattern formed by combining transmission periods and transmission suspension periods a predetermined number of times, and receives the status signal transmitted by the another alarm device (100) in an intermittent reception cycle. A time length of each of the transmission periods and the transmission suspension periods is set so that the another alarm device (100) that has failed to receive the status signal transmitted in a first intermittent reception cycle can receive the status signal in a second intermittent reception cycle and subsequent intermittent reception cycles.

Claims

1. An alarm device, comprising:

a status detection section;

a status judgment section for judging a status based on a signal output from the status detection section;

a control section for causing an alarm to be output based on a result of the judging made by the status judgment section; and

a transmitting/receiving section for transmitting and receiving a status signal to and from another alarm device, wherein;

the transmitting/receiving section transmits the status signal to the another alarm device with a transmission pattern formed by combining transmission periods and transmission suspension periods a predetermined number of times, and receives the status signal transmitted by the another alarm device in an intermittent reception cycle; and

a time length of each of the transmission periods and the transmission suspension periods is set so that the another alarm device that has failed to receive the status signal transmitted in a first intermittent reception cycle can receive the status signal transmitted in a second intermittent reception cycle and subsequent intermittent reception cycles.

2. An alarm device according to claim 1, wherein a total time length of the transmission periods is set to be equal to a time length of the intermittent reception cycle.

3. An alarm device according to claim 1, further comprising an alarm section for issuing the alarm,

wherein, in a case where the status signal that the transmitting/receiving section has received from the another alarm device is an alarm signal, the control section causes the alarm section to operate.

4. An alarm device according to claim 2, further comprising an alarm section for issuing the alarm,

wherein, in a case where the status signal that the transmitting/receiving section has received from the another alarm device is an alarm signal, the control section causes the alarm section to operate.