US 7,002,480 B2 · Deposit detector and control device using it

Abstract

A deposit detector in which deposit on a detection surface has a surface shape effect, and generation of a flashing phenomenon caused by irregular reflection of the light incident on the deposit from the outside is estimated. In a deposit detection mode, light emitted from a light source (10) for total reflection and total-reflected from the detection surface is received by a light-receiving element unit (50). Each element is disposed at such an angle that the light undergoes total reflection when no deposit is present or the condition of total reflection is not satisfied when deposit is present. Further, in a light-scattering deposit detection mode, light emitted from a scattering light source (20) and scattered by the detection surface is received by the light-receiving element unit (50). In an extraneous light quantity increase detection mode, extraneous light is received by the light-receiving element unit (50). Light detection signal generated while changing the mode is analyzed by a deposit estimation unit (60), and deposition of rain drops and increase in incident extraneous light quantity are detected to estimate generation of irregular reflection (flashing phenomenon) caused by the shape effect of deposit.

Claims19

Dependent claims

An object sensor having a light source for total reflection, wherein a sensing surface is an outer surface of a transparent substrate from which incident light emitted from the light source for total reflection and led in the transparent substrate is reflected,

the object sensor comprising:
a light-receiving unit for detecting extraneous light incident from the outside through the sensing surface and reflected light reflected from the sensing surface of the light source for total reflection;
an object sensing unit for detecting a reduction change in signal level due to the change of the reflection condition on the sensing surface by an object in a light detection signal detected by the light-receiving unit so as to detect the presence of the object;
and
an extraneous light quantity increase detection unit for detecting the presence or absence of the increase, due to a raindrop deposited on the detection surface, of the amount of extraneous light received by the light-receiving unit,
wherein when the presence of an object is detected by the object sensing unit and the increase in the light quantity is detected by the extraneous light quantity increase detection unit, the object sensor estimates the occurrence of a flashing phenomenon.

3 more elements

An object sensor having a light source for total reflection and a scattering light source, wherein a sensing surface is an outer surface of a transparent substrate from which incident light emitted from the light source for total reflection and led in the transparent substrate is reflected and onto which incident light emitted from the scattering light source and led in the transparent substrate is emitted,

the object sensor comprising:
a light-receiving unit for detecting extraneous light incident from the outside through the sensing surface, reflected light reflected from the sensing surface of the light source for total reflection, and a scattered light scattered from the sensing surface of the scattering light source;
an object sensing unit for detecting the change in signal level by an object from the light source of total reflection in a light detection signal detected by the light-receiving unit so as to detect the presence of an object;
a light-scattering object sensing unit for detecting the change in signal level by an object from the scattering light source in a light detection signal detected by the light-receiving unit so as to detect whether or not the object has a light-scattering property;
and
an extraneous light quantity increase detection unit for detecting the presence or absence of the increase of signals by extraneous light received by the light-receiving unit.

3 more elements

the object sensor comprising:
an image-formation system lens for forming an image of the sensing surface emitted by the light source for total reflection;
and
a light-receiving element array comprising a plurality of micro light-receiving elements, receiving light from the image formation-system lens and outputting the light detection signal from the micro light-receiving elements as a signal pattern in which the light detection signals are arranged in accordance with the arrangement of the micro light-receiving elements, wherein
when a portion having a signal pattern that is relatively lower than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by the emitted light from the light source for total reflection, the presence of an object is detected on the sensing surface corresponding to the pattern portion, and
when a portion having a signal pattern that is relatively higher than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by the extraneous light by turning off the light source for total reflection, the object sensor estimates the occurrence of flashing.

3 more elements

An object sensor having a light source for total reflection and a scattering light source, wherein a sensing surface is an outer surface of a transparent substrate from which incident light emitted from the light source for total reflection and led in the transparent substrate is reflected and incident light emitted from the scattering light source and led in the transparent substrate is scattered,

the object sensor comprising:
an image-formation system lens for forming an image of the sensing surface emitted by the light source for total reflection and scattering light source, and
a light-receiving element array comprising a plurality of micro light-receiving elements, receiving light from the image formation-system lens and outputting the light detection signal from the micro light-receiving elements as a signal pattern in which the light-detection signals are arranged in accordance with the arrangement of the micro light-receiving elements, wherein
when a portion having a signal pattern that is relatively lower than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by the emitted light from the light source for total reflection, the presence of an object is detected on the sensing surface corresponding to the pattern portion,
when a portion having a signal pattern that is relatively higher than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by a scattered light from the scattering light source, the presence of a light scattering type object is detected on the sensing surface corresponding to the pattern portion, and,
when a portion having a signal pattern that is relatively higher than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by an extraneous light by turning off the light source for total reflection and scattering light source, the object sensor estimates the occurrence of flashing.

3 more elements

A method for detecting an object, wherein a light source for total reflection and a scattering light source are used, and a sensing surface is an outer surface of a transparent substrate from which incident light emitted from the light source for total reflection and led in the transparent substrate is reflected and incident light emitted from the scattering light source and led in the transparent substrate is scattered, and,

an image-formation system lens for forming an image of the sensing surface emitted by the light source for total reflection and the scattering light source and a light-receiving element array comprising a plurality of micro light-receiving elements for receiving the image formed by the image-formation lens are used,
the method comprising:
producing a signal pattern in which light detection signals from the micro light-receiving elements of the light-receiving element array are arranged in accordance with the arrangement of the micro light-receiving elements;
detecting the presence of an object on the sensing surface corresponding to the pattern portion when a portion having a signal pattern that is relatively lower than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by the emitted light from the light source for total reflection;
detecting the presence of the light scattering type object on the sensing surface corresponding to the pattern portion when a portion having a signal pattern that is relatively higher than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by the emitted light from the scattering light source;
and
estimating the occurrence of a flashing when a portion having a signal pattern that is relatively higher than the surrounding signal level is detected in the signal pattern obtained by the light-receiving element array by extraneous light by turning off the light source for total reflection and the scattering light source.

4 more elements

Dependencies are inferred from the claim text.

Deposit detector and control device using it

Life of this patent

Deposit detector and control device using it

Life of this patent

Abstract

Claims19