US3661258A - Ultraviolet light label monitoring system - Google Patents

Abstract

A three-stage ultraviolet light label detection unit is provided for monitoring articles to detect and separate articles having luminescent, i.e., fluorescent or phosphorescent, imprints located thereon. The first detection stage uses ultraviolet light to sense the presence of luminescent imprints; the second control stage uses white light sensing to control the movement of articles passing thereby; the third reset stage also uses white light sensing to reset the control stage. Each stage acts through a logic circuit adapted to provide the desired detection and separation of luminescent from non-luminescent articles.

Description

United States Patent Madalo et al. [4 1 May 9, 1972 154] ULTRAVIOLET LIGHT LABEL 3,348,049 l0/l967 Stacey.....-. ..209/111.5 x

MONITORING SYSTEM 3,512,637 5/1970 Littlefield ..209/74 [72] Inventors: Michael Madalo, Whitehouse Station, Primary Examiner kichard A schacher N.J.; William H. Marlow, Nanuet, N.Y.

[73] Assignee: American Cyanamld Company, Stamford,

Conn.

221 Filed: Mar. 12, 1970 [21] Appl. No.: 18,945

[52] U.S. Cl. ..209/1 11.7 [51] Int. Cl. ..B07c 5/342 [58] Field of Search ..209/74, 1 i 1.5, ML?

[56] References Cited UNITED STATES PATENTS 3,l42,383 7/1964 Boyer ..209/11 L? X AMPLIFIER Attorney-Bryan, Parmelee, Johnson & Bollinger [57] ABSTRACT A three-stage ultraviolet light label detection unit is provided for monitoring articles to detect and separate articles having luminescent, i.e., fluorescent or phosphorescent, imprints located thereon. The first detection stage uses ultraviolet light to sense the presence of luminescent imprints; the second control stage uses white light sensing to control the movement of articles passing thereby; the third reset stage also uses white light sensing to reset the control stage. Each stage acts through a logic circuit adapted to provide the desired detection and separation of luminescent from non-luminescent articles.

5 Claims, 3 Drawing Figures LOGIC 36 AMPLIFIER 4o [AMPLIFIER 42 1 l l l 1 l l l l I 1 1 l l I l l I l l l 1 2s 32 I 30 1 ii RC. 501. 12. 1 14 25 WHITE 1 29 uv LIGHT LIGHT 1o SOURCES N SOURCESI 1 L w- ..1...AM J 1 18 J J H n/ FIRST STAG ssc'owo STAGE T(RPED5EJ1T L (DETECTION (CONTROL) ULTRAVIOLET LIGHT LABEL MONITORING SYSTEM SUMMARY OF THE INVENTION Our label monitoring system can most readily be described as a three-stage system. EAch stage performs a systematic function cooperating with the other two stages. The first is a detection stage; the second, a control stage; and, the third, a reset stage. The detection stage has a source of ultraviolet light arranged to illuminate an article passing by it. The article may be bottle, box, carton, or other container normally having a label on it.

The label contains a luminescent mark or imprint, so that, when the article bearing the label passes into the ultraviolet light zone and is illuminated, the luminescent material, if present, will fluoresce or phosphoresce, emitting radiation, usually of visible light. The emitted light activates a photocell included in the detection stage which in turn energizes a logic circuit electrically connected to the control stage.

The control stage is normally set to reject all articles passing through it, using a source of white light and a photocell detector to determine the presence of the articles. However, if the photocell in the detection stage senses luminescent material, the control stage is directed by the logic circuit not to reject the article, and so it is permitted to pass.

The reset stage includes another source of white light and another photocell to detect passing articles. This stage resets the control stage to its normal operating, i.e., automatic reject, state when the reset stage photocell is activated.

The monitoring system thus provides a three-stage detection and separation unit, controlled by the presence or absence of luminescent material on a label, for detecting and separating articles.

For a better understanding of the features and advantages of the present invention, the detailed description should be read in conjunction with the following figures.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view generally showing the arrangement of the articles and sequence of operation of the monitor- DETAILED DESCRIPTION STRUCTURE This invention discloses a label monitoring system using a pluralityof sequentially arranged stages, each stage performing a specific function in the detection and separation of labelled from non-labelled articles. Each label contains a luminescent material capable of activating a photocell when the luminescent material is exposed to ultraviolet light. The first stage inspects passing articles to detect the presence of luminescent imprints. The second stage, having a white light detector, controls the path of an article passing thereby. (It is nonnally set to reject the article unless a signal is received from the first stage). The third stage, also sensitive to white light, resets the control stage to its normal reject state.

The preferred form of our invention is shown in FIGS. 1, 2, and 3. FIGS. 1 and 2 show the structural layout, and FIG. 3 shows the logic circuitry.

Turning first to FIGS. 1 and 2, our system includes means for conveying an article, the three stages mentioned above, the logic control circuitry, and article rejection means.

For purposes of illustration,.we have shown bottles having labels 12 on them. Also shown is one bottle 11 without a label. The bottles are carried on a conveyor belt 18 which is shown moving to the right in the figures.

Each label should have a mark 14 of fluorescent material on it. It is this mark 14 which is detected in our system, thereby detecting the presence or absence of a label.

Positioned adjacent to belt 18 and preferably to one side of it, are detection, control and reset stages, in that order, identified by numerals 20, 24 and 28, respectively.

The first (detection) stage 20 includes source of ultraviolet light 21 and photocell detector 22. The second (control) stage 24 includes a source of visible light 25 and a photocell detector 26; and also includes a rejector 27. The third (reset) stage includes a source of visible light 29 and photocell detector 30.

The rejector 27 in the second stage may be of any desired type. A reject plunger, actuated by a solenoid 32, adjacent belt 18 and positioned to push bottles transversely off belt 18, is satisfactory. When actuated, the plunger pushes the bottle 10 onto a reject station 34, as shown by the arrows in FIG. 1.

The three stages and rejector are interconnected through logic circuit 36 and, if necessary, amplifiers 38, 40 and 42. That is, the output of first stage photocell 22 passes through amplifier 38 to logic circuit 36; and that of the third stage photocell 30, through amplifier 42, to logic circuit 36. The output from logic circuit 36 goes to solenoid 32 to control the reject plunger.

In our preferred form, logic circuit 36 is adapted to reject every bottle passing through control stage 24, unless it receives a signal from detection stage 20 indicating that luminescent material is present. Normally, logic circuit 36 actuates solenoid 32 each time a bottle 10 is detected in the second stage. Thus, the system is fail-safe. If, however, a signal is received from detection stage 20, indicating the presence of luminescent material, control stage 24 is deactivated, preventing rejection. When that bottle passes photocell 30 of the third stage, logic circuit 36 then reactivates, i.e., resets, control stage 24.

It should be realized that other types of logic programs could be used, if desired, in our three-stage system. For example, the second stage could be set to reject" when a signal is received indicating the presence of marking on the label. In such a case, the reset stage 28 would be positioned over the reject station 34.

A form of logic circuit which may be used is shown in FIG. 3. In essence, this circuit is designed to have solenoid 32 actu ated each time a bottle reaches the second stage, thus rejecting the bottle. This actuation is accomplished by having the second stage photocell 26 close the circuit to solenoid 32 each time it detects the presence of a bottle. If, however, a luminescent label on the bottle has been previously detected by photocell 22 at the first stage, solenoid 32 is deactivated and cannot reject.

The circuit itself includes solenoid coil 32 and resistor 33 in series with normally-open relay 46 controlled by second-stage photocell 26 and normallyclosed relay 48 controlled by first stage photocell 22. The coil and two relays are across a power supply 44, so solenoid 32 will operate when relays 46 and 48 are closed.

Closure of normallyopen relay 46 occurs when its photocell 26 detects a bottle. Thus, every bottle entering the second stage is rejected unless solenoid 32 is deactivated.

Deactivation occurs by short-circuiting solenoid 32. Relay coil 50, having normally-open contacts 54, is in series across the power supply with normally-open relay contacts 56 controlled by first-stage photocell 22. Thus, when a bottle with a luminescent label is detected by photocell 22, the circuit of contacts 56 and coil 50 is closed, shorting out solenoid 32 (since they are in parallel with it across the power supply.)

Energization of coil 50 also closes its associated relay contacts 54. Contacts 54 are in series with coil 50 and normallyclosed relay contacts 58 controlled by third stage photocell 30. This series circuit is in parallel with that of coil 50 and contacts 56, so solenoid 32 remains short-circuited even after the bottle leaves the first stage and contacts 56 again open.

Thus it can be seen that solenoid 32 will be deactivated, and so not reject a bottle entering the second stage, if a signal is received from the first stage.

Under these latter circumstances, however, the logic circuit must be reset to "reject" before the next bottle reaches the second stage. This happens because the then "passed" bottle moves to the third stage and is detected by photocell 30. This opens relay contact 58 and deenergizes coil 50. Solenoid 32 is thereby reset" since it is no longer shorted out. The cycle may then be repeated.

In summary, solenoid 32 rejects every bottle passing under photocell 26 unless prevented. It is prevented whenever photocell 22 detects a luminescent sample and so, through contact 56 and coil 50 shorts out and deactivates solenoid 32. Solenoid 32 will thereafter remain deactivated until a bottle, not rejected goes under photocell 30.

OPERATION The operation of our label monitoring system is as follows:

Normally, as bottle proceeds along the conveyor belt 18, the second stage photocell 26 will detect its presence, closing relay 46. This action closes the circuit to the reject solenoid 32, actuating the reject plunger 27 to push the bottle 10 off the belt 18 onto the reject station 34. Thus, the logic circuit is programmed to reject every bottle 10 unless prevented in some manner.

The prevention occurs through actuation of photocell 22 in the first stage 20 whenever the presence of luminescent material is detected on the bottle 10. Such actuation of the photocell 22 closes the normally-open relay 56 thereby shortcircuiting the reject solenoid 32, de-activating it.

Further, the activation of the relay coil 50 closes normallyopen contacts 54. This action of the relay coil 50 holds the circuit through the relay coil 50 closed even after the bottle 10 passes the photocell detector 22 opening relay 56. Thus, the action of the relay coil 50 prevents the rejection of a bottle 10 until it is deactivated.

Deactivation occurs when an accepted bottle 10 is detected by photocell 30. When such detection occurs the normallyclosed relay 58 is opened, deactivating the relay coil 50 and returning the circuit to its original setting as described above and as shown in FIG. 3.

It should be understood that the various arrangements of the stages or modification in the construction thereof may be made by one skilled in the art without departing from the spirit or scope of the invention as set forth in the specification and claims.

We claim:

1. Apparatus for sorting articles in accordance with the presence or absence of luminescent material thereon, said ap paratus including a detection stage, a control stage, and a reset stage, a detector in each said stage, said detection stage detector being adapted to detect radiations from activated luminescent material, a logic circuit interconnecting said detectors to receive information therefrom, a conveyor to carry said articles sequentially through said stages, a rejector in said control stage controlled by said logic circuit, said logic circuit activating and deactivating said rejector in accordance with whether or not said detection stage detector finds luminescent material present on said articles as they pass through said detection stage.

2. Apparatus as set forth in claim 1, in which said logic circuit is adapted to actuate said rejector each time one of said articles passes through said control stage unless said detection stage detector has found luminescent material present on said article when it passed through said detection stage.

3. Apparatus as set forth in claim 2, in which said logic circuit is reset to cause said rejector to thereafter reject each time one of said articles is detected by said reset stage detector.

4. Apparatus for sorting articles including a detection stage including a detector therein sensitive to radiations from activated luminescent material, a following control stage including a visible light detector and a rejector therein, and a following reset stage including a visible light detector, said detectors and said rejector being interconnected through a logic circuit,

said logic circuit beinig programmed to actuate said rejector to re ect each said artic e as it passes through said control stage and is detected by said control stage detector unless said detection stage detector has found luminescent material on said article, said reset stage detector resetting said logic circuit to again cause rejection of articles as soon as a non-rejected article leaves said control stage and is detected by said reset stage detector.

5. Apparatus for sorting articles as set forth in claim 4, in which said logic circuit controls said rejector by deactivating same each time said detection stage detector finds the presence of said luminescent material and by reactivating same every time said reset stage detector detects the presence of one of said articles.

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Claims (5)

1. Apparatus for sorting articles in accordance with the presence or absence of luminescent material thereon, said apparatus including a detection stage, a control stage, and a reset stage, a detector in each said stage, said detection stage detector being adapted to detect radiations from activated luminescent material, a logic circuit interconnecting said detectors to receive information therefrom, a conveyor to carry said articles sequentially through said stages, a rejector in said cOntrol stage controlled by said logic circuit, said logic circuit activating and deactivating said rejector in accordance with whether or not said detection stage detector finds luminescent material present on said articles as they pass through said detection stage.

2. Apparatus as set forth in claim 1, in which said logic circuit is adapted to actuate said rejector each time one of said articles passes through said control stage unless said detection stage detector has found luminescent material present on said article when it passed through said detection stage.

3. Apparatus as set forth in claim 2, in which said logic circuit is reset to cause said rejector to thereafter reject each time one of said articles is detected by said reset stage detector.

4. Apparatus for sorting articles including a detection stage including a detector therein sensitive to radiations from activated luminescent material, a following control stage including a visible light detector and a rejector therein, and a following reset stage including a visible light detector, said detectors and said rejector being interconnected through a logic circuit, said logic circuit being programmed to actuate said rejector to reject each said article as it passes through said control stage and is detected by said control stage detector unless said detection stage detector has found luminescent material on said article, said reset stage detector resetting said logic circuit to again cause rejection of articles as soon as a non-rejected article leaves said control stage and is detected by said reset stage detector.

5. Apparatus for sorting articles as set forth in claim 4, in which said logic circuit controls said rejector by deactivating same each time said detection stage detector finds the presence of said luminescent material and by reactivating same every time said reset stage detector detects the presence of one of said articles.

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