METHODE ET DISPOSITIF DE TRI DE LAMPES FLUORESCENTES

METHOD AND APPARATUS FOR SORTING FLUORESCENT LAMPS

Abrégé anglais

The invention relates to a method and a device for sorting
fluorescent lamps in terms of phosphor blends. The lamps
have a cylindrical lamp body (1) with a right-hand and
left-hand end and with a symbol imprint.
The fluorescent lamps are conveyed into an inspection
station (10) which has stop means (11, 12) for defining an
inspection plane (13) against which the lamp body (1)
respectively to be examined bears. A camera (21) is
directed onto the symbol imprint of the lamp body (1)
respectively to be examined. A rotating device (15, 16) in
the inspection station (10) is started up in order to
rotate the lamp body (1) respectively to be examined. The
camera (21) outputs pixel signals to an image processing
system (30), which obtains image data from the pixel
signals. The image processing system (30) contains image
memories with data for recorded symbols, and an
image-comparing device which correlates the image data with the
recorded symbol data. The respectively examined
fluorescent lamp is conveyed out of the inspection station
(10) and directed into one of a plurality of sorting paths
via a switching system (25).

Revendications

7
Claims
1. A method for sorting, in terms of phosphor blends,
fluorescent lamps which have a cylindrical lamp body with
a right-hand and left-hand end and with a symbol imprint
characteristic of a specific manufacturer and type of
lamp,
comprising the steps of:
a) providing an inspection station with an image
processing system having image memory means for
recoding symbol data relating to symbol imprints from
different manufacturers, said image processing system
also having means for converting pixel signals into
actual image data and for comparing said actual image
data with said recorded symbol data;
b) conveying said lamps into said inspection station
having stop means for defining an inspection plane,
each lamp body to be examined engaging said
inspection plane;
c) directing a camera to which said image processing
system is connected onto said symbol imprint of each
lamp body to be examined;
d) rotating each lamp body to be examined in the
inspection station while said camera is directed onto
said symbol imprint;
e) outputing pixel signals from the camera to the image
processing system and obtaining said actual image
data from said pixel signals;
f) correlating said actual image data with said recorded
symbol data for producing a control signal indicative
of the symbol imprint which is present on the lamp

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under inspection; and
g) conveying each inspected lamp out of the inspection
station and directing same into one of a plurality of
sorting paths via a switching system which is
controlled by said control signal.
2. The method set forth in claim 1,
wherein said lamps are conveyed in a horizontal alignment
of their bodies until reaching, in a succession of lamps,
said stop means formed by an angular prism.
3. A sorting apparatus for sorting fluorescent lamps,
each having a cylindrical lamp body with ends on opposite
sides and with a symbol imprint on one of its ends,
the symbol imprints of different lamps may differ from one
another,
the apparatus comprising
conveying means for intaking said lamps in succession,
said conveying means including a stop surface for checking
said lamp bodies, said stop surface defining an inspection
plane and being dimensioned so that the ends of said lamp
bodies remain free from said stop surface;
a rotating device for rotating each lamp body when
engaging said stop surface;
at least one camera having an image plane which is aligned
with said inspection plane including one of the ends of
said lamp body, said camera providing pixel signals from
said lamp body end in said image plane;
an image processing system comprising image memory means
for recording data characteristics of said symbol
imprints, and image comparing means, said image processing
system being connected to said at least one camera so as
to obtain actual image data from said pixel signals and

9
correlate said actual image data with said recorded data
from said symbol imprints; and
outlet conveying means including a switching system for
said lamps which have passed said inspection station, said
image processing systems controlling said switching system
so as to sort said lamps according to their symbol
imprints.
4. The apparatus set forth in claim 3,
wherein one of the cameras is adapted to be moved parallel
to the inspection plane so as to adapt to different
lengths of the lamp bodies under inspection.
5. The apparatus set forth in claim 3,
wherein said conveying means includes an inclined surface
having a lower end with two stop angles which in
connection with one another define a prismatic body which
supports each said lamp body.
6. The apparatus set forth in claim 5,
wherein one stop angle is stationary and the other stop
angle is adapted to be moved along said prismatic body so
as to adapt said prismatic body to support different
lengths of the lamp bodies under inspection.

Description

CA 02344307 2001-06-26
99HB 1492CAP
Herborn Paul
Method and apparatus for sorting_fluorescent lamps
Field of the Inventio~a
The invention x~elat.es to a method and an apparatus
for sorting fluoresc:e:nt lamps or tubes in terms of
phosphor blends.
Background of the Invention
It is important: to recover the phosphor when
recycling fluorescent lamps. However, the various
manufacturers of fluorescent lamps use different additives
to the basic phosphor, and this renders the recovery of
the basic phosphor E=xtremely difficult.
Summary of the Invention
In order to avoid these difficulties, the inventor
has developed a concept of desiring to recover not the
phosphor as such, but the phosphor blends as they occur in
the various types of lamps of the various manufacturers.
It is therefore the object of the invention to create
a method and an apparatus for sorting fluorescent lamps
which are such as to permit sorting in terms of phosphor
blends.
In an embodiment of the invention, the fluorescent
lamps to be sorted are fed to an inspection station such
that they are at a predetermined distance from at least
one camera. Each fluorescent lamp is rotated in order to
read the imprint lo~~a.ted in the vicinity of the lamp foot
and feed it to an image processing system. The imprint
generally contains a

CA 02344307 2001-06-26
2
company logo with a type identification composed of
letters and numerals. 'The image processing system contains
a memory for data recordal from such company logos and
type identification., so that the respectively examined
fluorescent tube care be assigned to a specific
manufacturer and the:1=ype of lamp by means of comparison.
This renders it possible to sort the fluorescent lamps
with regard to their phosphor blends.
In the case of f:Luorescent lamps, the imprint is
1.o always located only at one end thereof in a region of
approximately 80 mm width from the en.d of the lamp body.
When used fluorescent lamps are delivered into the
inspection station, the distribution of the ends with an
imprint or without an imprint relative to the station is
arbitrary. In order to tackle this problem, it is possible
to provide a double pass through the inspection station, a
previously undetected fluorescent lamp being rotated by
180° before the second pass, such that its correct end
passes by the camera.
ao However, it is also possible to provide two cameras
which are each direc:t~ed onto an assigned end of the lamp
body. In this configuration of the invention, one of the
cameras is of movable design in order to be able to adapt
to the different lengths of fluarescent tubes, which can
:?5 be of length in the region of between 350 and 1800 mm.
Use may be made for the purpose of supporting the
lamps in the inspection station of two angles which are
arranged at a distaruce from one another and whose
connecting lines together produce an aligning prism. The
3o supporting angles are to be arranged at a predetermined
distance from the ends of the fluorescent lamps, in order
not to disturb the tube end inspection by the cameras. One
of the supporting angles is of movable configuration in

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3
order to be able to adapt to the specified length range of
from 350 to 1800 mm of the fluorescent lamps.
Brief Description of the Drawings
Details of the invention are explained with the aid
of the drawing, in which:
Figure 1 shows a schematic overall view, and
Figure 2 shows an en:Larged detail from Figure 1.
Lo Detailed Description of the Embodiment
Fluorescent lamps 1 are transported individually by a
bucket conveyor 2 to a:n intake conveying path 3 which
comprises an inclined raceway. A guiding top surface 4
ensures that the fluorescent tubes 1 arrive in an
inspection station 1.0 in a horizontally aligned fashion.
Provided in the inspe~~tion station 10 are stops 11 and 12
which are designed i.n the present case as stop angles and
define a prism in conjunction with one another in order to
hold the lamp body of the fluorescent tube 1 at a defined
2o distance from a right-hand camera 21 or a left-hand camera
22. The prism defined by the angle stops 11 and 12
includes two mutualJ.y perpendicular faces of which each
can be used as an inspection plane assigned to the cameras
21 or 22, respectivEaly. In the illustrated exemplary
<?5 embodiment, the stop surface 13 at a steeper angle to the
roll surface 3 is to be used as inspection plane.
Consequently, the viewing directions of the cameras 21 and
22 are aligned perpendicularly to this plane 13, and the
distance of the cameras is selected such that the plane 13
:3o is sharply imaged in the camera.
Assigned to each stop angle 11 or 12 are pairs of
rolls 15 and 16, re:~pectively, which are arranged at a
tangent to the stop plane 13, as is best illustrated in

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4
Figure 2. The rolls 15 or 16 is respectively assigned a
friction roll drive 1; or 18, in order to drive the
respective roll 15 or 16, and thus to rotate the lamp body
1 located in the inspection station.
The stop angle 17. and the assigned rolls 15 are
arranged in a stationary fashion, while the stop angle 12,
together with its rolls 16, can be moved in the direction
in which the inspection station 10 extends, as is
indicated by the double arrow 19. The displacement of the
to stop angle 12 together with the rolls 16 can be performed
by means of a spindle and a guide, this not being
illustrated for reasons of clarity.
In the same way as the stop angle 12 can be
displaced, the camera 22 can also be displaced parallel to
the longitudinal extent of the inspection station 10, as
is indicated by the arrow 23. A spindle and guide can be
used for this purpose; other means of displacement can
also be used. The displacement of the stop angle 12 and
the camera 22 allows t:he device to be adapted to changing
lengths of the lamp bodies 1. When the device is designed
for a maximum length of the lamp bodies 1 of 1800 mm, the
stop angle 11 is located at a distance of approximately
150 mm from the end of. the lamp body 1. The movable stop
angle 12 can be moved up to a distance of 150 mm from the
end of the lamp body 7... If shorter lamps are present for
checking, the movable stop angle is moved to the right in
the drawing, in order to leave free approximately 150 mm
to the end of the lamp body. The camera 21 is arranged in
a stationary fashion and aligned with an end region of the
lamp body 1 which is of_ width 80 mm and on which the
manufacturer's imprint: with manufacturer's symbol and type
identification is to be expected. The movable camera 22 is
directed onto the respective end of the lamp body 1,

CA 02344307 2001-06-26
specifically onto a region of likewise 80 mm width.
The two camera~s:zl and 22 are connected to an image
processing system 30 which can pick up digital image
information coming from the cameras as pixel signals and
5 compare it to stored image information. This stored image
information relates to the imprints to be expected at the
end of the lamp body, specifically as regards manufacturer
and type of lamp. In general, company symbols or logos and
letter/numeral combinations are imprinted, the size of the
_!.0 imprint depending on the type of lamp. When the lamp body
1 is rotated during checking, and the imprint moves
through the visual f:ielc~ of the camera 21, the company
logo and the type identification are read off in the
sequence to which we are accustomed. If, by contrast, the
:~5 symbol imprint is located at the left-hand end of the lamp
body, the camera 22 reads the symbol imprint backwards.
This is taken into account during processing in the image
processing system. I:f the image processing system has a
monitor 31 for monitoring purposes, then said monitor is
2o fed such that the imprint appears in the correct reading
direction for a person.
Connected to the image processing system 30 is a
switching controller 32 which ensures that the lamp body
respectively checked is correctly sorted. This is
25 performed in an out=Let conveying path 24, which can be
designed as an inclined raceway with a row of flaps 25. By
reversing the rolls 15 and 16, the lamp body respectively
located in the inspection station 10 is raised above the
height of the stop <~n.gle 11 and 12 and then reaches the
3o raceway 24 and rolls downward thereupon. Each flap 25 has
a flap drive which is respectively connected to the
switching controller 32. The switching controller 32 has
as many outputs as there are phosphor blends plus a

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further output for r~on-identified phosphor blends. The
flaps 25 are assigned to the respective outputs of the
switching controller :32, such that upon the detection of a
specific class of fluorescent tubes by manufacturer and
type of lamp or types of lamp, to which a specific
phosphor blend is a~ss:igned, an assigned flap 25 is opened
and the downward rolling fluorescent tube lands in a
container located the:rebelow.
The new sorting method permits relatively quick
1o detection of the class of the fluorescent tube under
examination. It is possible to contemplate cycle times
from 2 seconds to 0.5 seconds. The selectivity of the
detection of the symbol imprint is very high, "symbol
imprint" being understood both as the company logo and as
u5 the type identificat:.ion. Lamps whose classification cannot
be unambiguously detected are processed in the previously
customary way. In this way, the phosphor blends recovered
from the fluorescent:. tubes are recovered with a quality
which is extremely high since it is not impaired by
:?0 admixtures. The phosphor blends are obtained from the
fluorescent tubes in the usual manner by opening the
fluorescent tubes and blowing out the coating with
compressed air.

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