Person-detecting sensor and automatic water faucet

Patent metadata

Field	Value
Publication number	US-2016083943-A1
Application number	US-201514952174-A
Country	US
Kind code	A1
Filing date	Nov 25, 2015
Priority date	May 31, 2013
Publication date	Mar 24, 2016
Grant date	—

Abstract

A person-detecting sensor includes: a range-finding unit that decides whether a distance to a detection object falls within a predetermined detection distance range; a received-light quantity decision unit that decides whether a received-light quantity is equal to or greater than a predetermined received-light quantity threshold; and a continuation decision unit that decides whether a state of the detection object being present is ongoing. In the received-light quantity decision unit, after water discharge is started upon the detection determination unit determining a detection object to be under detection state, for a period during which the continuation decision unit decides the state in which the detection object being present is ongoing, the received-light quantity threshold is set to be lower than prior to when the water discharge is started.

First claim

What is claimed is:

1 . A person-detecting sensor for an automatic water faucet provided with an imaging unit that includes an imaging element in which pixels are arranged either one-dimensionally or two-dimensionally, and a light-emitting unit disposed offset from the imaging unit in a predetermined direction, wherein the imaging unit, receiving reflected light generated by light incident from the light-emitting unit, detects a person, as a detection object, located within a predetermined detection distance range, the person-detecting sensor comprising:
an imaging operation control unit that controls an imaging operation carrying out light emission by the light-emitting unit and light receiving by the imaging unit; a readout unit that reads out the respective received-light quantities of pixels constituting the imaging element; a range-finding unit that identifies position where the reflected light is incident in a light-receiving region, which is a region in which pixels constituting the imaging element are arrayed in the predetermined direction, and that decides whether distance to the detection object derivable by the principle of triangulation from the incident position falls within the predetermined detection distance range; a received-light quantity decision unit that performs a determination by a threshold with regard to the received-light quantity read out by the readout unit, and decides whether the received-light quantity is equal to or greater than a predetermined received-light quantity threshold; a detection determination unit that determines a detection object to be under detection state when distance to the detection object is decided by the range-finding unit to fall within the predetermined detection distance range and the received-light quantity is decided by the received-light quantity decision unit to be equal to or greater than the received-light quantity threshold; and a continuation decision unit that decides whether a state of a detection object being present is ongoing; wherein in the received-light quantity decision unit, after water discharge is started upon the detection determination unit determinating a detection object to be under detection state, for a period during which the continuation decision unit decides the state in which the detection object being present is ongoing, the received-light quantity threshold is set to be lower than prior to when the water discharge is started.

2 . A person-detecting sensor as set forth in claim 1 ,
wherein the continuation decision unit detects a temporal change of the reflected light so as to detect the presence of a moving object and decides that the state of the detection object being present is ongoing when the continuation decision unit detects the moving object.

3 . A person-detecting sensor as set forth in claim 2 ,
wherein the continuation decision unit decides that the state of the detection object being present is ongoing during a predetermined period after water discharge is started upon the detection determination unit determinating the detection object to be under the detection state.

4 . An automatic water faucet comprising:
a water faucet that discharges water to the inside of a bowl provided with a drainage port at the bottom of the bowl; a person-detecting sensor according to claim 1 ; and a water supply control unit that performs the switching of discharging and stopping of water from the water faucet by using a sensor signal that is output by the person-detecting sensor depending on whether the current state is a detection state or a non-detection state.

5 . An automatic water faucet comprising:
a water faucet that discharges water to the inside of a bowl provided with a drainage port at the bottom of the bowl; a person-detecting sensor according to claim 2 ; and a water supply control unit that performs the switching of discharging and stopping of water from the water faucet by using a sensor signal that is output by the person-detecting sensor depending on whether the current state is a detection state or a non-detection state.

6 . An automatic water faucet comprising:
a water faucet that discharges water to the inside of a bowl provided with a drainage port at the bottom of the bowl; a person-detecting sensor according to claim 3 ; and a water supply control unit that performs the switching of discharging and stopping of water from the water faucet by using a sensor signal that is output by the person-detecting sensor depending on whether the current state is a detection state or a non-detection state.

Assignees

• Lixil Corp

Inventors

• Shirai Yuki
• Itazu Nobuaki
• Oura Hiroyuki

Classifications

• E03C1/057 Primary

  touchless, i.e. using sensors · CPC title

• G01V8/20

  using multiple transmitters or receivers · CPC title

• G01S17/04

  Systems determining the presence of a target · CPC title