Smoke detector capable of distinguishing smoke and particles
AssigneePixart Imaging Inc.
InventorsCheng-Nan Tsai, Guo-Zhen Wang, Ching-Kun Chen, Yen-Chang Chu, Chih-Ming Sun
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Abstract
There is provided a smoke detector including a first light source, a second light source surface, a light sensor and a processor. The light sensor receives reflected light when the first light source and the second light source emit light, and generates a first detection signal corresponding to light emission of the first light source and a second detection signal corresponding to light emission of the second light source. The processor distinguishes smoke and floating particles according to a similarity between the first detection signal and the second detection signal.
Claims14
A smoke detector, comprising:
- a light sensor, configured to generate a detection signal;
- and
- a processor, configured to
- select one set of condition thresholds from multiple sets of predetermined condition thresholds according to a profile of the detection signal, wherein the one set of condition thresholds is configured to be compared with the detection signal to determine whether to give an alarm, and
- change a sensing frequency of the smoke detector according to a normalized intensity of the detection signal.
A smoke detector, comprising:
- a light sensor, configured to respectively generate a detection signal corresponding to light of different wavelengths;
- and
- a processor, configured to select one set of condition thresholds from multiple sets of predetermined condition thresholds according to a profile of the detection signal, wherein
- the one set of condition thresholds comprises a normalized intensity threshold corresponding to light of a single wavelength, and a signal ratio of detection signals corresponding to light of two different wavelengths, and
- the processor is configured to firstly categorize the profile according to a normalized intensity of the detection signal and the normalized intensity threshold, and then select the one set of condition thresholds from the multiple sets of predetermined condition thresholds corresponding to the categorized profile.
Dependencies are inferred from the claim text.