Human body detection sensor and automatic faucet

Patent metadata

Field	Value
Publication number	US-9758952-B2
Application number	US-201514753472-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Dec 28, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A human body detection sensor includes: a detection decision unit that decides whether a state is a detection state or a non-detection state of a detection target; a specular reflection decision unit that decides whether or not reflected light that is incident onto a line sensor is specularly-reflected light; and a continuation decision unit that decides whether or not a state in which the detection target exists is ongoing, wherein, when specularly-reflected light is detected while a determination is made indicating the detection state, the detection decision unit keeps the result of a determination indicating the detection state without change if the result of the decision by the continuation decision unit indicates that the state is ongoing and changes the determination to a determination indicating the non-detection state if the result of the decision shows any other states.

First claim

What is claimed is:

1. A human body detection sensor for detecting a detection target provided with: an imaging unit that includes an imaging element in which pixels are arranged in a one-dimensional manner or in a two-dimensional manner; and a light-emitting unit disposed with an offset from this imaging unit, in which the imaging unit receives reflected light generated by light projected by this light-emitting unit, comprising:
a specular reflection decision unit that decides whether or not the reflected light is specularly-reflected light; and
a continuation decision unit that decides whether or not a state in which the detection target exists is ongoing,
wherein, when the reflected light is decided to be specularly-reflected light during the detection of the detection target, a determination indicating detection is kept if the result of the decision by the continuation decision unit indicates that the state is ongoing, and a determination indicating non-detection is made if the result of the decision by the continuation decision unit indicates that the state is not ongoing,
wherein the continuation decision unit is configured to detect a temporal change of the reflected light so as to decide the presence of a moving object and decide that the state in which the detection target exists is ongoing when the continuation decision unit decides that the moving object is present.

2. An automatic faucet for use with a detection target and a bowl, the automatic faucet comprising:
a faucet that discharges water into the bowl provided with a drainage port at the bottom of the bowl;
a human body detection sensor for detecting the detection target provided with: an imaging unit that includes an imaging element in which pixels are arranged in a one-dimensional manner or in a two-dimensional manner; and a light-emitting unit disposed with an offset from this imaging unit, in which the imaging unit receives reflected light generated by light projected by this light-emitting unit, comprising:
a specular reflection decision unit that decides whether or not the reflected light is specularly-reflected light; and
a continuation decision unit that decides whether or not a state in which the detection target exists is ongoing,
wherein, when the reflected light is decided to be specularly-reflected light during the detection of the detection target, a determination indicating detection is kept if the result of the decision by the continuation decision unit indicates that the state is ongoning, and a determination indicating non-detection is made if the result of the decision by the continuation decision unit indicates that the state is not ongoing,
wherein continuation decision unit is configured to detect a temporal change of the reflected light so as to decide the presence of a moving object and decide that the state in which the detection target exists is ongoing when the continuation decision unit decides that the moving object is present; and

a water supply control unit that performs the switching of discharging and stopping of water from the faucet by using a sensor signal that is output depending on whether this human body detection sensor is in a detection state or in non-detection state.

3. The human body detection sensor according to claim 1 ,
wherein the continuation decision unit decides that there is the moving object when a temporal difference of a center of gravity of the reflected light is more than a predetermined threshold value, and
wherein the predetermined threshold is a value of sub-pixel numbers.

4. The human body detection sensor according to claim 3 , wherein ten sub-pixels correspond to one pixel of the imaging element.

5. The human body detection sensor according to claim 4 , wherein the predetermined threshold value is five sub-pixels.

Assignees

• Lixil Corp

Inventors

• Shirai Yuki
• Itazu Nobuaki
• Oura Hiroyuki
• Tanaka Kenta

Classifications

• G01S17/04

  Systems determining the presence of a target · CPC title

• G01V8/20

  using multiple transmitters or receivers · CPC title

• E03D5/105

  touchless, e.g. using sensors · CPC title

• G01S17/48

  Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves · CPC title

• E03C1/057 Primary

  touchless, i.e. using sensors · CPC title