Separate-type detector with redundant synchronization feature
First Claim
1. A separated smoke sensor comprising:
- a light transmitting unit configured to wirelessly transmit detection light to a monitoring area; and
a light receiving unit configured to wirelessly receive detection light transmitted by the light transmitting unit to the monitoring area, determine presence of smoke in the monitoring area based on a detection amount of the received detection light, and output an accident-warning signal to a receiving device that is connected to the light receiving unit via a line when the light receiving unit determines that smoke is present;
wherein the light transmitting unit and the light receiving unit are laid out separately from each other and facing each other, sandwiching the monitoring area;
wherein the light transmitting unit is configured to receive electric power from a local power source connected to the light transmitting unit or from a battery incorporated within the light transmitting unit;
wherein the light receiving unit is configured to receive electric power from the receiving device;
wherein the light transmitting unit having a light source and a light-transmission control unit;
wherein the light source is configured to wirelessly transmit the detection light;
wherein the light-transmission control unit is configured to control transmission of the detection light by the light source by a predetermined transmission time at a predetermined light transmission interval;
wherein the light receiving unit includes;
a light receiving element configured to wirelessly receive the detection light transmitted by the light source and output a voltage or a current corresponding to an amount of the received detection light;
a synchronization-establishment processing unit configured to;
execute a predetermined process establishing synchronization between the light transmitting unit and the light receiving unit based on the detection light received by the light receiving element;
execute a predetermined light reception operation that receives the detection light by a predetermined reception time at a predetermined light reception interval different from the light transmission interval;
determine presence of reception of the detection light during the light reception operation, and when reception is determined; and
specify, as a synchronization timing, a timing that arrives at a same interval as the predetermined light transmission interval, based on a timing at which the detection light is received;
a light-extinction-amount calculation unit configured to calculate a light extinction amount of the detection light received by the light receiving element based on a voltage or current output by the light receiving element at the synchronization timing established by the synchronization-establishment processing unit; and
a smoke determining unit that determines the presence of smoke in the monitoring area based on the light extinction amount calculated by the light-extinction-amount calculation unit and a predetermined threshold value.
1 Assignment
0 Petitions
Accused Products
Abstract
An object is to provide a separated sensor capable of synchronizing a light transmitting unit with a light receiving unit, without using a control line.
There is provided a separated sensor including a light transmitting unit that transmits detection light to a monitoring area, and a light receiving unit that receives detection light transmitted by the light transmitting unit, the light transmitting unit and the light receiving unit laid out separately from each other. On one of the light transmitting unit and the light receiving unit, there is provided a synchronization-light transmitting unit that transmits, by wireless, synchronization light to synchronize the light transmitting unit with the light receiving unit. On the other of the light transmitting unit and the light receiving unit, there are provided a synchronization-light receiving unit that receives the synchronization light transmitted from the synchronization-light transmitting unit, and a synchronization-establishment processing unit that performs a predetermined process to establish the synchronization based on the synchronization light received by the synchronization-light receiving unit.
3 Citations
9 Claims
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1. A separated smoke sensor comprising:
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a light transmitting unit configured to wirelessly transmit detection light to a monitoring area; and a light receiving unit configured to wirelessly receive detection light transmitted by the light transmitting unit to the monitoring area, determine presence of smoke in the monitoring area based on a detection amount of the received detection light, and output an accident-warning signal to a receiving device that is connected to the light receiving unit via a line when the light receiving unit determines that smoke is present; wherein the light transmitting unit and the light receiving unit are laid out separately from each other and facing each other, sandwiching the monitoring area; wherein the light transmitting unit is configured to receive electric power from a local power source connected to the light transmitting unit or from a battery incorporated within the light transmitting unit; wherein the light receiving unit is configured to receive electric power from the receiving device; wherein the light transmitting unit having a light source and a light-transmission control unit; wherein the light source is configured to wirelessly transmit the detection light; wherein the light-transmission control unit is configured to control transmission of the detection light by the light source by a predetermined transmission time at a predetermined light transmission interval; wherein the light receiving unit includes; a light receiving element configured to wirelessly receive the detection light transmitted by the light source and output a voltage or a current corresponding to an amount of the received detection light; a synchronization-establishment processing unit configured to; execute a predetermined process establishing synchronization between the light transmitting unit and the light receiving unit based on the detection light received by the light receiving element; execute a predetermined light reception operation that receives the detection light by a predetermined reception time at a predetermined light reception interval different from the light transmission interval; determine presence of reception of the detection light during the light reception operation, and when reception is determined; and specify, as a synchronization timing, a timing that arrives at a same interval as the predetermined light transmission interval, based on a timing at which the detection light is received; a light-extinction-amount calculation unit configured to calculate a light extinction amount of the detection light received by the light receiving element based on a voltage or current output by the light receiving element at the synchronization timing established by the synchronization-establishment processing unit; and a smoke determining unit that determines the presence of smoke in the monitoring area based on the light extinction amount calculated by the light-extinction-amount calculation unit and a predetermined threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification