US 12,424,070 B2
Smoke detector and optical sensing system
Ching-Kun Chen, Hsin-Chu (TW); and Guo-Zhen Wang, Hsin-Chu (TW)
Assigned to PixArt Imaging Inc., Hsin-Chu (TW)
Filed by PixArt Imaging Inc., Hsin-Chu (TW)
Filed on Jul. 12, 2023, as Appl. No. 18/221,377.
Prior Publication US 2025/0022357 A1, Jan. 16, 2025
Int. Cl. G08B 17/107 (2006.01); G01N 21/47 (2006.01)
CPC G08B 17/107 (2013.01) [G01N 21/4738 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A smoke detector, comprising:
a light source, configured to emit light;
an optical sensor, configured to sense optical data generated according to the light, comprising;
a first oscillator, configured to generate a first oscillating signal with a first oscillating frequency; and
a second oscillator, configured to generate a second oscillating signal with a second oscillating frequency different from the first oscillating frequency;
a first processing circuit, configured to generate a first command to instruct the first oscillator to oscillate for a first expected oscillating time, and configured to receive the first oscillating signal and then acquire a first real oscillating time in which the first oscillator really oscillates responding to the first command, wherein the first processing circuit further computes a time relation between the first expected oscillating time and the first real oscillating time, wherein the first processing circuit generates a second command to instruct the second oscillator to oscillate for a second expected oscillating time according to the time relation; and
a second processing circuit, configured to control the smoke detector to generate a first alarm according to the time relation.