IP Library Granted Patent US 12,424,070
Granted Patent B2
US 12,424,070 · App. 18/221,377 · Granted Sep 23, 2025

Smoke detector and optical sensing system

Inventors: Ching-Kun Chen (Hsin-Chu, TW); Guo-Zhen Wang (Hsin-Chu, TW)
Assignee: PixArt Imaging Inc.
G08B17/107G01N21/4738
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Quick Facts
Patent No.
US 12,424,070
App. No.
18/221,377
Granted
Sep 23, 2025
Kind
B2
Abstract

A smoke detector comprises a light source, an optical sensor, a first, and a second processing circuit. The optical sensor senses optical data and comprises; a first oscillator, generating a first oscillating signal; and a second oscillator, generating a second oscillating signal. The first processing circuit generates a first command to instruct the first oscillator to oscillate for a first expected oscillating time, and acquires a first real oscillating time, wherein the first processing circuit further computes a time relation between the first expected oscillating time and the first real oscillating time. 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. The second processing circuit controls the smoke detector to generate a first alarm according to the time relation. The optical sensor can also be applied to other electronic devices.

Claims (26)

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.

2. The smoke detector of claim 1 , wherein the second processing circuit controls the smoke detector to generate the first alarm according to the time relation before controls the smoke detector to generate a second alarm according to the optical data.

3. The smoke detector of claim 1 , wherein the second processing circuit controls the smoke detector to generate the first alarm simultaneously according to the optical data and the time relation.

4. The smoke detector of claim 1 ,

wherein first processing circuit further generates a third command to instruct the second oscillator to oscillate for a third expected oscillating time before acquires the time relation;

wherein the first processing circuit generates the second command to instruct the second oscillator to oscillate for the second expected oscillating time according to the time relation, thereby a second real oscillating time in which the second oscillator really oscillates responding to the second command is equal to the third expected oscillating time.

5. The smoke detector of claim 1 , wherein the optical sensor computes an exposure time according to one of the first oscillating signal and the second oscillating signal, and computes a frame interval time according to the other one of the first oscillating signal and the second oscillating signal.

6. The smoke detector of claim 1 , wherein the first oscillating frequency is higher than the second oscillating frequency.

7. The smoke detector of claim 6 , wherein the optical sensor computes an exposure time according to the first oscillating signal and computes a frame interval time according to the second oscillating signal.

8. The smoke detector of claim 1 , wherein the first oscillating frequency is lower than the second oscillating frequency.

9. The smoke detector of claim 8 , wherein the optical sensor computes a frame interval time according to the first oscillating signal and computes an exposure time according to the second oscillating signal.

10. The smoke detector of claim 1 ,

wherein first processing circuit further generates a fourth command to instruct the first oscillator to oscillate for a fourth expected oscillating time according to the time relation, thereby a third real oscillating time in which the first oscillator really oscillates responding to the second command is equal to the first expected oscillating time.

11. The smoke detector of claim 1 , wherein the time relation is a time ratio between the first expected oscillating time and the first real oscillating time.

12. 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 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; and

a second processing circuit, configured to control the smoke detector to generate a first alarm according to the time relation.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 12, 2023
From: CHEN, CHING-KUN; WANG, GUO-ZHEN
To: PIXART IMAGING INC.
Reel/Frame 064234/0140 →
Continuity (1)
Related Publication 20250022357A1 · Jan 16, 2025
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