Note: Descriptions are shown in the official language in which they were submitted.
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Title: RESIDUAL FLUID DETECTION APPARATUS
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to detection
apparatus and more particularly, is directed to a residual liquid
detection apparatus which detects the remaining liquid such as
the washing liquid or the like at the bottom of bottles such as
transparent bottles made of glass or the like.
Description of the Prior Art
Drinking water or beverages such as beer and the like are
loaded into glass bottles and marketed, but there is the bottle
washing process before filling the bottles with the liquid.
Especially, in the case of recycled bottles such as beer bottles
that are reused after use by the consumer and recovery, a
thorough washing of the bottle is necessary in view of mixtures
of trash or disposals inside the bottle oftenly. In this case,
washing is conducted to the bottles with detergent liquid and
cleanwater, but there are cases where such detergent mixed water
remains in the bottle due to the incomplete water removal from
the bottle thereupon. Needless to say, the contents are for
human consumption and hence it is not desired that such residual
liquid remains in the bottle prior to the filling.
As for the residual liquid detection methods in bottles of
conventional means, there are methods that detect residual liquid
by the absorbance ratios of high frequency waves or supersonic
waves or infrared rays by the residual liquid, or otherwise by
bringing the electrodes near the liquid there are methods that -
detect the residual liquid by the differences in the capacitance
therebetween. The present trend lies mainly with detection
methods by the infrared ray utilizations.
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However, when the volume of the r~sidual liquid is large,the residual liquid detection is relatively easy by any methods
mentioned above, but it is extremely difficult to detect very
small volumes of ]iquid remained, whereas it is de~ired to have
available such apparatus that will provide stable detection of
very small volumes of the residual liquid.
As above cited, while it is possible to detect the residual
liquid of certain volume by the prior art method, the problem
remains with the detection of very small volume of residual
liquid. One reason that makes the detection difficult is the
fact that the smaller the residual liquid volume is the less the
light ray absorption thereby becomes. The secondary reason is
that the containers (mostly glass bottles) to which the liquid is
filled, also absorb the light rays to a certain extent when the
light rays pass through the same and it is often the case that
the received light ray contents at such photoelectric conversion
sensors vary depending upon the container wall thickness as well
as applied colours to the container.
In order to detect the very small volume of the residual
liquid, it is necessary to amplify and magnify the subtle
variations of the photoelectric converted voltage from the
photoelectric conversion sensor. Such amplified magnification of
the variation at the same time magnifies the variation owing to
the passage of lights through the container walls and accordingly
it becomes difficult to detect the true variation of the received
light by the real residual liquid by such influence. Therefore,
there is a limit in the detection of very small volumes of
residual liquid and it is the present practice to accept such
detection only over a certain volume.
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OsJECTS AND SU~MARY OF THE ~NVENTION
Accordingly, it is an object of the present invention to
provide a residual liquid detection apparatus free from the
defects encountered to the prior art.
It is another object of the present invention to provide a
residual liquid detection apparatus which can detect a liquid of
small amount which remains on the bottom of a transparent bottle
positively.
It is a further object of the present invention to provide a
residual liquid detection apparatus which can detect a residual
liquid of small amount on the bottom of a transparent bottle
positively regardless of the thickness of the bottle, its colour
and so on.
According to a first aspect of the present invention there
is provided a residual liquid detection apparatus for detecting
whether or not liquid remains at the bottle bottom of a
transparent bottle, which comprises:
a) a light source for irradiating light that contains
visible light and infrared rays onto the bottle bottom of a
transparent bottle;
b) two photoelectric conversion sensors for receiving light
that has passed said bottle bottom from said light source;
c) an optical filter which only passes the infrared rays
and is placed in front of the light receiving surface of one of
said photoelectric conversion sensors; and
d) a circuit for comparing outputs from said two
photoelectric conversion sensors and delivering a signal when a
difference between the outputs exceeds a predetermined value.
According to a second aspect of the present invention there
is provided a residual liquid detection apparatus for detecting
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~hether or not liquid remains at the bottle bottom of a
transparent bottle, which comprises:
a) a light source located under the bottle bottom of a
transparent bottle and for irradiating light that contains
visible light and infrared rays onko the bottle bottom of said
transparent bottle;
b) a light diffusing plate located between said light
source and said bottle bottom;
c) two photoelectric conversion sensors located above the
bottle mouth of said transparent bottle and for receiving light
that has passed said bottle bottom from said light source;
d) a condenser lens located between said two photoelectric
conversion sensors and said bottle mouth;
e) an optical filter which only passes the infrared rays
and is placed in front of the light receiving surface of one of
said photoelectric conversion sensors; and
f) a circuit for comparing outputs from said two
photoelectric conversion sensors and delivering a signal when a
difference between the outputs exceeds a predetermined value.
~ ccording to a third aspect of the present invention there
is provided a residual liquid detection apparatus for detecting
whether or not liquid remains at the bottle bottom of a
transparent bottle, which comprises:
a) a light source located under the bottle bottom of-a
transparent bottle and for irradiating light that contains
visible light and infrared rays onto the bottle bottom of said
transparent bottle;
b) a light diffusing plate located between said light
source and said bottle bottom;
c) two photoelectric conversion sensors located above the
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,ottle mouth of said transparent bottle and for receiviny light
that has passed said bottle bottom from said light source;
d) a condenser lens located be-tween said two photoelectric
conversion sensors and said bottle mouth;
e) an optical ~ilter which only passes the infrared rays
and is placed in front of the light receiving surface of one of
said photoelectric conversion sensors;
f) a light splitter located between said condenser lens and
said two photoelectric conversion sensors; and
g) a circuit for comparing outputs from said two
photoelectric conversion sensors and delivering a signal when a
difference between the outputs e~ceeds a predetermined value,
wherein an optical axis of said condenser lens is made coincident
to a center axis of said bottle, said photoelectric conversion
sensor with no optical filter is located to receive the light
which propagates along said optical axis and passes said light
splitter, and the other photoelectric conversion sensor is
located to receive the light which propagates along said optical
axis and is reflected by said light splitter.
According to a fourth aspect of the present invention there
is provided a residual liquid detection apparatus for detecting
whether or not liquid remains at the bottle bottom of a
transparent bottle, which comprises:
a) a light source located under the bottle bottom of a
transparent bottle and for irradiating light that contains
visible light and infrared rays onto the bottle bottom of said
transparent bottle;
b) a light diffusing plate located between said light
source and said bottle bottom;
c) two photoelectric conversion sensors located above the
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~ottle mouth o~ said transparent bottle and for receiving light
that has passed said bottle bottom from said light source;
d) a condenser lens located between said two photoelectric
conversion sensors and said bottle mouth;
e) an optical filter which only passes the infrared rays
and is placèd in front of the light receiving surface of one of
said photoelectric conversion sensors; and
f) a circuit for comparing outputs from said two
photoelectric conversion sensors and delivering a signal when a
difference between the outputs exceeds a predetermined value,
wherein an optical axis of said condenser lens is made coincident
to a center axis of said bottle, said two photoelectric
conversion sensors are concentrically located with respect to
said optical axis on the same plane.
The above, and other objects, features and advantages of the
present invention will become apparent from the following
detailed description taken in conjunction with the accompanying
drawings through which like reference numerals designate the same
and similar elements.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a block diagram showing an embodiment of the
present invention;
Fig. 2 is a schematic diagram that is used to explain the
functions of the same;
Fig. 3 is a block diagram showing a second embodiment of the
present invention;
Figs. 4A and 4B are schematic diagrams used to explain a
third embodiment of the present invention;
Fig. 5 is a schematic diagram showing a main part of the
third embodiment of the present invention;
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Fig. 6 is a block dia~ram showing a fourth embodiment of the
present invention; and
Figs. 7A and 7B are schematic diagrams showing a main part
of a fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A residual liquid detection apparatus according to the
present invention will now be described with referehce to the
drawings attached.
Fig. 1 shows a partial cross section schematic diagram of an
embodiment of the residual liquid delection apparatus according
to the present invention. In Fig. 1, 1 is, for example, a glass
bottle or the like in which residual liquid 2 exists at the
bottom 11, 3 is a light source which is located under the bottle
bottom 11 and irradiates light that includes visible light as well
as infrared rays on the bottom 11 from underneath the bottle 1; 4
is a light diffusion plate that is placed between the bottle
bottom 11 and the light source 3 in order to cause an even
irradiation of the light from light source 3 onto the bottle
bottom 11; and 5 is a condenser lens that is placed above the
bottle mouth in order to converge the light that has passed the
bottle bottom 11, whereas the optical axis of the condenser lens
5 is arranged to match the center axis of the bottle 1 as
indicated as OA. 61, 62 are two photoelectric conversion sensors
that are placed above the condenser lens 5 in a parallel manner
each other to grip the optical axis OA; 7 is an optical filter
that only passes therethrough infrared rays and is located in
front of the light receiving face of one photoelectric conversion
sensor 62; 81, 82 are two amplifiers that respectively boost the
photoelectric converted outputs from photoelectric conversion
sensors 61, 62; 9 is a zero adjuster such as a potentiometer that
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~djusts and zeros the voltage differences between the two
amplifiers 81, 82; and 10 is a power amplifier which is connected
to an intermediate tap 91 of the zero adjuster g in order to
generate a detection output signal as atermentioned.
Photoelectric conversion sensors 61, 62 are located close to
each other so that the optical image of bottle bottom 11, which
is formed by focussing the light passed through the bottle bottom
11 by means of condenser lens 5, occupies both the photoelectric
conversion sensors 61, 62 by similar areas (which will be
described later in connection with Fig. 2). The electrical
outputs from photoelectric conversion sensors 61, 62 are
respectively amplified at amplifiers 81, 82 and supplied to zero
adjuster 9. If a positive phase amplifier is used as amplifier
81, while a negative phase amplifier is used as amplifier 82 and
the outputs from both the amplifiers 81, 82 are supplied to zero
adjuster 9, the voltages at the both ends of the zero adjuster or
potentiometer 9 will be reversed in phase to each other.
Therefore, when there is no existence of residual liquid 2 at
bottle bottom 11, both photoelectric conversion sensors 61, 62
and so on are adjusted to make the voltage at intermediate tap 91
of zero adjuster or potentiometer 9 as zero. Then, when the
irradiated light is received by the sensors 61, 62 under the
condition without any residual liquid 2 at bottle bottom 11, if
there is a slight voltage difference at the intermediate tap 91
of potentiometer 9, the potentiometer 9 can be adjusted to make
the voltage difference at its intermediate tap 91 to be zero.
The light source which emits both of visible lights as well
as infrared rays is used as the light source 3, while one
photoelectric conversion sensor 61 receives the light that has
passed the bottle bottom 11 as well as the residual liquid 2 at
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_he bottle bottom 11 as it i.s. On the other hand, since there is
the optical filter 7 which only passes the infrared rays placed
in front of the light receiving surface of photoelectric
conversion sensor 62, it only receives the in~rared rays o~ the
passed light.
Generally speaking, in the case of infrared rays with long
wave length in the range of 1 to 2 microns, the attenuation
coefficient of infrared rays passed through liquid becomes
extremely large and accordingly, in the case that there is
residual liquid 2 at the bottle bottom 11 the photoelectric
converted output from the photoelectric conversion sensor 62 that
only receives the infrared rays becomes extremely smaller as
compared with that from photoelectric conversion sensor 61. As
for the optical filter 7, any proper type that has a cutoff
frequency range of the above mentioned range will suffice.
Photoelectric conversion sensor 61 also receives the lights
in the visible zone, whereas the attenuation amount of the lights
in the visual zone when passing through the liquid is small so
that the amount of light received by photoelectric conversion
sensor 61 does not show large variations by the existence or not
of residual liquid 2. From the above reason, by the existence or
not of residual liquid 2, there will be a large difference
generated between the electrical outputs from the amplifier 81
that is connected to photoelectric conversion sensor 61 and the
amplifier 82 that is connected to photoelectric conversion sensor
62. Therefore, if the zero adjuster 9 is so adjusted that the
voltage difference at the output terminal 91 of zero adjuster 9
that is connected to amplifiers 81, 82 is nil, when there is no
residual liquid 2 at the bottle bottom 11, a voltage difference
will appear at the output terminal 91 of zero adjuster 9 only
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~hen there is residual liquid 2 existing on the bottom 11 of
bottle 1.
The output from zexo adjuster 9 is supplied to power
amplifier 10. This power amplifier 10 will be adjuste~ to
generate an electrical output that indicates the detection o~
residual liquid 2 at the bottle bottom 11 when the voltage from
the zero adjuster 9 exceeds a predetermined constant value.
Needless to say, by utilizing the electrical output from this
power amplifier 10, although not shown on Fig. 1, alarming means
by light or sound may be driven, or a bottle rejection system may
be activated to remove the bottles that have residual liquid 2
existence detected.
Fig. 2 is a plane diagram that shows magnified light
receiving areas of photoelectric conversion sensors 61 and 62,
respectively. In Fig. 2, llA is an inner diameter area of bottle
bottom 11, and 121, 122 are the light received areas of the
photoelectric conversion sensors 61, 62 corresponding to the inner
diameter area llA. The two photoelectric conversion sensors 61,
62 are installed close together, but are only slightly displaced
from the optical axis OA of the condenser lens 5 so that there
will be a slight difference between the light received areas 121,
122. However, although there is a slight difference in the light
receiving areas, from the purpose of residual liquid 2 detection,
this in fact does not create any problem. Even in the case that
the photoelectric conversion sensors 61, 62 are setup so that the
lights from different portions of the bottle bottom 11 are
received by the photoelectric sensors 61, 62, respectively,
according to the functional principles of the present invention
as described above, it is apparent that the purpose o~ the
present invention can be accomplished.
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Fig. 3 shows a second embodiment of the prèsent invention.
In this case, such above described difference in the light
receiving areas of photoelectric convexsion sensors 61, 62 will
not occur. In other words, as shown in Fig. 3, on the optical
axis OA of the condenser lens 5, a light splitter 13 such as a
half mirror, a prism or the like is placed between the condenser
lens 5 and photoelectric conversion sensors 61, 62 so that one
photoelectric conversion sensors such as 61 will receive the
light that has passed the bottle bottom 11, the condenser lens 5
and then the half mirror 13 along the optical axis OA, while the
other photoelectric conversion sensor 62 will receive the light
refracted by half mirror 13. By such arrangement the light
receiving areas of photoelectric conversion sensors 61, 62 can be
made to match. The other parts of the second embodiment will be
exactly the same to those of the embodiment of Fig. 1.
Fig. 4 and Fig. 5 are schematic diagrams showing the main
part of a third embodiment of the present invention. Of the
bottles 1, there is such one in which a central portion at the
bottom 11 of bottle 1 is protruded upwards as shown in Fig. 4A,
which is a sectional side view of the bottom portion. In this
case, when the amount of the residual liquid 2 is small, such
residual liquid 2 will be spread in a doughnut like shape at the
outer circumference area of the center portion of the bottle
bottom 11 and shall not exist at the center protruded portion of
the bottom 11.
In order to effectively detect the existence of residual
liquid 2 at such bottle, the third embodiment of the present
invention shall be explained in reference with Fig. 4B that shows
a proiection diagram of bottle bottom 11 and Fig. 5 that show the
main part of the third embodiment. In other words, as shown on
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. ig. 4B, it is arranged so that one photoelectric conversion
sensor 61 will only receive the light that passes the central
protruded portion 141 of bottle bottom 11, while the other
photoelectric conversion sensor 62 will only receive the light
that passes the doughnut like portion 142 around the center
protruded portion 141 of bottle bottom 11. By such arrangement,
the photoelectric conversion sensor 62 will largely be affected
by the attenuation degree of the passed light dependent on the
existence or not of the residual liquid 2, so that an effective
detection of a small amount of residual liquid 2 is possible.
That is to say that, as shown on Fig. 5, an optical mask 151
is placed in front of the light receiving surface of
photoelectric conversion sensor 61 and an optical mask 152 is
placed in front of the light receiving surface of photoelectric
conversion sensor 62. As shown on the plane diagram and
indicated by arrow A in Fig. 5, optical mask 151 is formed of,
for example, a disc-shaped transparent portion 15A at the center
portion thereof and an opaque portion 15B surrounding the same.
The other optical mask 152, as shown by arrow B on the plane
diagram of Fig. 5, is formed of a disc-shaped opaque central
circular portion l5C, a doughnut-shaped transparent portion 15D
surrounding the same and another ring-shaped opaque section 15E
surrounding the portion 15D. Therefore, the respective optical
masks 151 and 152 are limited to the light receiving areas
corresponding to the portions 141, 142 as explained with Fig. 4B.
Also it is needless to say that even if the entire passing light
through bottle bottom 11 is received by the photoelectric
conversion sensor 61 while omitting optical mask 151 therefor, it
will not become an obstacle to the function of the above
described functions of the present invention. Also although not
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shown on Fig. 5, the other structure and functions of this
embodiment are exactly the same as those of the embodiment on
Fig. 3.
Fig. 6 is a schematic diagram showing a fourth embodiment of
the present invention whereas the structures of the photoelectric
conversion sensors 61, 62 are special so that without the use of
the half mirror 13, the light passed through bottle bottom 11 is
received by the photoelectric sensors 61, 62 at one place on the
optical axis OA to perform the purpose of the present invention.
In other words, the shape of photoelectric conversivn sensor 61
is made in a small disc like shape while the photoelectric
conversion sensor 62 is made into a doughnut like shape to
surround the former as shown on the projection diagram of the
same in Fig. 6 and both the photoelectric conversion sensors 61,
62 are placed to be on the same plane and concentric to the
optical axis OA. By this arrangement, photoelectric conversion
sensor 61 will only receive the light passed through the center
portion of the bottle bottom 11 while photoelectric conversion
sensor 62 will receive the light only passed through the outer
circumference doughnut-shaped portion of bottle bottom 11, which
in effect will provide the same function to that of the
embodiment of Fig. 5. It is needless to say that it will
be necessary to install the same doughnut like-shaped infrared ray
filter 7 in front of the light receiving surface of photoelectric
conversion sensor 62 which is also doughnut-shaped.
The above explained various embodiments of the present
invention were equ~lly in reference with a structured arrangement
where the bottle bottom 11 is irradiated from under the bottom 11
and the light passed through the bottom 11 is received above the
bottle mouth, but in order to practice the present invention, it
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.s not necessary to be limited to the above structures and many
other constructions may be considered.
Fig. 7A and 7B are a partial cross sectional diagram showing
the side view and plane views of a fith embodiment of the
present invention. As shown on Figs. 7A and 7B, the
photoelectric conversion sensors 61 and 62 are placed at the
outside of the bottle 1 near the bottle bottom 11. In this case,
the light source 3 is split into two projection type light
sources 31, 32 which are placed outside the bottle bottom 11, so
that the light sources 31 and 32 are in countering positions to
the photoelectric conversion sensors 61, 62 at the outside in
relation to the diameter of bottle bottom 11. The locations of
the light sources 31 and 32 will be arranged so that such
respective light beams shall pass the residual liquid 2 and be
received by the photoelectric conversion sensors 61, 62
respectively in order that the detection of the residual liquid 2
will be effective. The other structures and functions of this
embodiment are the same to those of the previously explained
embodiments and such drawings and explanations shall not be
cited.
F7~rther, explanations were made on these embodiments in the
cases of convenient photoelectric conversion sensor utilizations,
but with the use of video cameras and CPU or the like, it will be
easy for anyone skilled in the art to enable commencement of the
main functions and effects of the present invention by logics.
According to the present invention, the prior difficulty to
detect small amounts of residual li~uid becomes easy, with the
additional merit to remove such hazardous causes to the
improvement of detection precision stability by the container
(glass bottles or the like) thickness or variations in the colour
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:hereof.
It should be understood that the above descripkion is
presented by way of example on the preferred embodiments of the
invention and it will be apparent that many modifications and
variations thereof could be effected by one with ordinary skill
in the art without departing from the spirit and scope of the
novel concepts of the invention so that the scope of the
invention should be determined only by the appended claims.
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