Title:
煙感知器
Document Type and Number:
Japanese Patent JP7406356
Kind Code:
B2
Abstract:
To provide a smoke detector capable of issuing warning sound without giving discomfort when ringing means such as a buzzer for generating continuous sound is arranged, and also capable of suppressing a deviation of a measurement value of a smoke density during ringing.SOLUTION: A smoke detector stores a circuit board mounting a measurement circuit for measuring a physical amount related to a smoke density and a control circuit, and includes ringing means (24) for generating continuous sound. The circuit board (13) includes a drive circuit for driving the ringing means and the storage circuit. When controlling the measurement circuit to perform measurement during ringing of the ringing means by controlling the drive circuit, the control circuit gradually changes a ringing sound level of the ringing means so as not to be recognized by a human auditory sense, and allows the measurement circuit to perform density measurement in a period when ringing sound is at the minimum level within a variation range.SELECTED DRAWING: Figure 3
Inventors:
Shinsuke Forest
Satoshi Yanagisawa
Satoshi Yanagisawa
Application Number:
JP2019212807A
Publication Date:
December 27, 2023
Filing Date:
November 26, 2019
Export Citation:
Assignee:
Nittan Co., Ltd.
International Classes:
G08B17/103; G08B17/00; G08B23/00
Domestic Patent References:
| JP2018136808A | ||||
| JP2009146233A | ||||
| JP2009031833A | ||||
| JP2010033235A |
Attorney, Agent or Firm:
Hiroshi Arafune
Yoshio Arafune
Yoshio Arafune