Alarm device
AssigneeHochiki Corporation
InventorTomohiko Shimadzu
Life of this patent
Estimating the term…
Abstract
A detection unit that detects smoke contained in a gas by radiating detection light toward a detection space for detecting smoke, and an inner labyrinth for inhibiting ambient light from entering the detection space, the inner labyrinth being provided to cover an outer edge of the detection space are included, the detection unit includes a light emitting unit that radiates the detection light and a light receiving unit that receives the detection light radiated by the light emitting unit, and at least a part of a side surface of the inner labyrinth on a side of the detection space is formed in a flat shape capable of inhibiting the detection light reflected by the inner labyrinth from entering a field of view RV of the light receiving unit in the detection space.
Claims5
An alarm device comprising:
- a detection unit that detects a substance to be detected contained in a gas by radiating a detection light toward a detection space for detecting the substance to be detected;
- and
- a light shielding unit that inhibits ambient light from entering the detection space, the light shielding unit being provided to cover an outer edge of the detection space, wherein the light shielding unit includes at least two light shielding walls,
- wherein the detection unit includes a light emitting unit that radiates the detection light and a light receiving unit that receives the detection light radiated by the light emitting unit, wherein a first corner is formed by intersecting the at least two light shielding walls so that the light receiving unit is positioned between the corner and the light emitting unit, and
- at least a part of a side surface of the light shielding unit on a side of the detection space is formed in a flat shape capable of inhibiting the detection light reflected by the light shielding unit from entering a field of view of the light receiving unit in the detection space, wherein the light emitting unit radiates the detection light toward the first corner so that the detection light illuminates the first corner.
Dependencies are inferred from the claim text.