WO2000061301A1

WO2000061301A1 - Encoding symbologies and graphics on nonporous materials

Info

Publication number: WO2000061301A1
Application number: PCT/US2000/009500
Authority: WO
Inventors: Larry Donald Reed; Arnold Davis Knott
Original assignee: Tec-Masters, Inc.
Priority date: 1999-04-09
Filing date: 2000-04-07
Publication date: 2000-10-19
Also published as: AU4222900A; WO2000061301A9

Abstract

The method and apparatus particularly adapted for use with articles (12) comprised of nonporous hardened materials such as glass. The method includes the step of applying ink to a portion of a surface (16) of each article (12) in the inventory of articles (12). The method further includes the step of directing a laser (18) towards the portion of the surface (16) to which the ink has been applied to cure the ink and to bond the ink with, and embed the ink in the surface (16) of the article (12). The laser (18) is directed by a computer (20) in a plurality of predetermined patterns to impart unique, serialized graphics to each article (12), for example, a data matrix symbol, a manufacture's logo, and other identifiers. The method also includes the step of recording information corresponding to the graphic and may be recorded using a charged coupled device (24).

Description

ENCODING SYMBOLOGIES AND GRAPHICS ON NONPOROUS MATERIALS

This application claims the benefit of U.S. Provisional Patent Application No. 60/128,619 filed April 9, 1999. The entire disclosure of U.S. Provisional Patent Application No. 60/128,619 is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to manufacturing and inventory control systems and, in particular, to a method and apparatus for encoding serialized graphics on each article of manufacture in an inventory of such articles wherein the articles are comprised of hardened nonporous materials. 2. Disclosure of Related Art

It is a common practice in many industries to place serial numbers or other unique identifiers on various articles of manufacture. The use of these identifiers can serve a variety of purposes. For example, the identifiers allow coordination of the manufactured articles with raw material lot numbers, quality inspection results, or other technical information useful to the manufacturer both during the manufacturing process and after the articles have left the manufacturing facility. The identifiers can also be useful in theft deterrence and resolution and in coordinating product recalls.

The placement of unique identifiers on articles comprised of hardened nonporous materials, however, can be difficult to implement. For example, in the glass industry, manual or semi- automated silk screening has been used to impart graphics such as a manufacturer's logo onto the surface of the glass. Silk screening is not a commercially viable process for imparting a unique identifier to each glass article, however, because any change in the graphic requires hard tooling changes and the process is inefficient for high volume production. An attempt has been made to place a unique identifier on a ceramic-based carrier member that is attached to the glass surface m the manner of a label. Labels, however, often fail to maintain their adhesive properties over time and are a relatively inefficient means of imparting unique identifiers to the articles Further, the ink graphic on the carrier often degrades at certain temperature levels. Finally, several obstacles must be overcome in forming the glass articles. For example, the resulting mark or label must be able to withstand tempering oven temperatures exceeding 1400 degrees Fahrenheit. The mark or label must also be pliable or otherwise able to adapt to the forming of curvatures m the glass articles after application of the marking or label. Finally, the marking or label must not significantly deform or compromise the physical integrity of the glass component .

It is known in some manufacturing and inventory control systems to etch a unique, decodeable identifier into an article of manufacture using a laser. For example, lasers have been used to etch serial numbers m components for internal combustion engines. A computer-controlled laser generates a relatively high- intensity, short exposure beam that heats and deforms the metallic surfaces of the engine components to permanently imprint the serial number. For articles comprised of certain materials such as glass, however, this process may compromise the structural integrity of the article. Moreover, it is difficult to provide sufficient resolution for some graphics (e.g., manufacturing logos and various data matrix symbols) on such materials using the laser-etching process.

There is thus a need for a method and apparatus for inventory control of manufactured articles- -and particularly those comprised of nonporous hardened materials- -that will minimize or eliminate one or more of the above-mentioned deficiencies. SUMMARY OF THE INVENTION

The present invention provides an apparatus and a method of inventory control for articles of manufacture.

An apparatus in accordance with the present invention includes means, such as a conventional spray applicator, for applying an ink to at least a portion of a surface of each article of manufacture in the inventory of articles. The apparatus also includes a laser and means, such as a computer operating under the control of a set of programming instructions (i.e., software), for directing the laser towards the portion of the surface of each of the articles to which the ink has been applied in order to cure the ink and to bond the ink with, and embed the ink in, the surface of each article. The laser may be directed in a plurality of predetermined patterns to form a unique, serialized, and decodeable graphic on each article within the inventory of articles. The graphic may include a decodeable data matrix symbol for uniquely identifying the article, a manufacturer's logo, and other information (e.g., a patent number for the article). An apparatus in accordance with the present invention may also include means, such as a charge coupled device (CCD) , for recording information corresponding to the graphic on each article.

A method in accordance with the present invention for inventory control of a plurality of articles of manufacture includes the step of applying an ink to at least a portion of a surface of a first article of the inventory of articles. The method also includes the step of directing a laser towards the portion of the surface of the first article to which the ink has been applied to cure the ink and to bond the ink with, and embed the ink in, the surface of article. The laser is directed in a first predetermined pattern to form a first graphic on the surface of the first article. As set forth above, the graphic may include a decodeable data matrix symbol, a manufacturer's logo, and other information (e.g., a patent number for the article). The method may further include the steps of applying the ink to at least a portion of a surface of a second article of the inventory of articles and directing the laser m a second predetermined pattern to form a second graphic on the second article that is different from the first graphic previously formed on the first article The inventive method may finally include the step of recording information corresponding to the first and second graphics.

An apparatus and method m accordance with the present invention represent a significant improvement as compared to conventional manufacturing and inventory control systems. First, the inventive apparatus and method allow application of a permanent, encoded identifier to articles of manufacture comprised of hardened nonporous materials without compromising the structural integrity of the articles. Second, the inventive apparatus and method are more efficient and economical than known manufacturing and inventory control systems. In particular, the use of a computer-controlled laser to generate unique patterns allows high-volume, repetitive operation without the necessity for tooling changes. Further, the computer- controlled laser provides consistent marking and relatively high levels of resolution to the graphics formed on the articles. Finally, the use of a charge coupled device or other recording means enables the inventive apparatus and method to both decode and decipher the data within the graphics while allowing transmission and storage of the data for improved inventory control .

These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagrammatic view illustrating an inventory control apparatus m accordance with one embodiment of the present invention. Figure 2 is a plan view of a portion cf an article of manufacture produced in accordance with the present invention.

Figure 3 is a diagrammatic view illustrating an inventory control apparatus in accordance with another embodiment of the present invention.

Figure 4 is a flow chart diagram illustrating a method of inventory control in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views, Figure 1 illustrates an apparatus 10 for controlling an inventory of articles 12-...12_n of manufacture in accordance with one embodiment of the present invention. In the illustrated embodiment, articles 12₁...12_n comprise vehicle windows and, particularly, vehicle windshields. It should be understood, however, that the inventive apparatus and method disclosed herein could be applied in a similar fashion to a wide variety of articles of manufacture. The inventive apparatus and method are preferably provided for use in controlling inventories of manufacturing articles comprised of hardened nonporous materials. It should be understood, however, that the inventive apparatus and method may find application with respect to manufacturing articles comprised of other materials. Furthermore, although the illustrated articles 12₁...12_n are comprised of glass, it should be understood that the inventive apparatus and method may be used with a variety of hardened nonporous materials including, for example, ceramics and porcelain.

Apparatus 10 may include means, such as a spray applicator 14, for applying an ink to at least a portion of a surface 16 of each article 12. Apparatus 10 may also include a laser 18 and means, such as a computer 20 operating under the control of a set of programming instructions (i.e., software), for directing laser 18 in a predetermined pattern across the portion of surface to which the ink has been applied. Referring to Figure 2, this action cures the ink and bonds the ink with, and embeds the ink in, surface 16 of article 12 to form a graphic 22 on article 12. Referring again to Figure 1, apparatus 10 may also include means, such as charge coupled device

(CCD) 24, for recording information corresponding to graphic 22.

Referring again to Figure 2, graphic 22 may include a wide variety of information including, for example, a manufacturer's logo

24 and a patent number 26. Preferably, however, graphic 22 also includes an identifier that uniquely identifies each article 12 with respect to other articles 12 within the inventory of articles

12₁...12_n. In a preferred embodiment, this identifier is encoded within a data matrix symbol 28 (also known commercially as an ID matrix or 2-D code matrix symbol among other names) . It should be understood, however, that the identifier may be encoded in other data symbologies such as a bar code or may simply be expressly disclosed within graphic

22 (e.g., in the form of a number) . It should also be understood that symbol 28 may include information in addition to the unique identifier.

For example, symbol 28 may include information such as the raw material lot number and the date of manufacture for article 12. Symbol 28 may be derived from a proprietary marking system of a manufacturer or may be drawn from a conventional data matrix symbology. In one successful test of the inventive apparatus and method, a data matrix symbol having the following characteristics was formed on article 12 as part of graphic 22:

CHARACTERISTIC VALUE

Symbology ANSI #BC11-1997

Size 0.4375 sq . inches

Cell Size 0.025-0.050 sq. inches

Lines Per Cell 8

Rows/Columns Variable

ECC level 200

Referring again to Figure 1, spray applicator 14 is provided to apply an ink to at least a portion of surface 16 of each article 12.

Applicator 14 is conventional in the art. Applicator 14 may be controlled in response to control signals generated by computer 20 and may be used to apply a plurality of coatings of the ink to surface 16. Alternatively, a plurality of applicators 14 may be used with each applicator 14 applying a single coat of ink to surface 16 responsive to control signals generated by computer 20. The ink may comprise any of a number of inks presently used in manual or semi -automated silk- screening processes, such as the ink sold by Cerdec Corporation- - Drakenfeld Products of Washington, Pennsylvania under the designation DRK-220-116 Black Glass Marking Ink. In one constructed embodiment, two or three coats of the ink were applied to surface 16 of article 12 in a manner such that the ink was sufficiently thick to present a uniform, opaque appearance to the naked eye.

Referring to Figure 3, in an alternate embodiment of the inventive inventory control apparatus 10' the means for applying the ink to surface 16 of article 12 includes an ink carrier 30 mounted to a feed reel 32 and a takeup reel 34 on either side of laser 18. Carrier 30 is provided to carry the ink and may comprise a vinyl-type film or another film similar to a typewriter ribbon that allows the ink to be released from carrier 30 in the presence of heat. Reels 32, 34 are provided to position carrier 30 and the ink over surface 16 of article 12 and in front of the beam produced by laser 18 and to intermittently advance carrier 30 as each article 12 is moved into position with respect to laser 18. Reels 32, 34 are conventional and may be mounted to laser 18 or another structure. Reels 32, 34 may be controlled through a conventional electromechanical control system operating in response to control signals from computer 20. One advantage of an apparatus 10' in accordance with the present invention is that no excess uncured and unbonded ink remains on surface 16 of article 12 after forming graphic 22. As a result, surface 16 does not need to be cleaned and less ink is required.

Laser 18 is provided to generate a relatively low-intensity, short exposure beam that heats the ink and surface 16 of article 12. This action cures the ink and slightly deforms surface 16 by melting surface 16, thereby allowing the ink to become embedded in and bonded to surface 16. Laser 18 may comprise the 75 , diode-pumped YAG laser manufactured by Control Micro Systems, Inc. of Winter Park, Florida.

In one successful test of the inventive apparatus, a laser 18 having the following characteristics was used to impart graphics 22 consisting of (i) a data matrix symbol 28 and (ii) a data matrix symbol 28 and a manufacturer's logo 24 to a glass vehicle windshield:

CHARACTERISTIC VALUE

Aperture 1.2-2.4 mm

Current 9.5 Amps

Power 0.3 Watts

Speed 50.0 mm/s

Frequency 0 (constant wave) Line Orientation (Horizontal) Scale 1.0

Lens Size 160 mm

Beam Width 0.15 mm

Beam Expansion 5X

The graphic consisting of the data matrix symbol 28 alone was about

0.4375 square inches in size while the graphic consisting of the data matrix symbol 28 and manufacturer's logo 24 was about 1.25 square inches in size. Each graphic was of medium (50%) density. The time required to impart the graphic to the article was about 3-4 seconds for the data matrix symbol 28 alone and about 18-22 seconds for both the data matrix symbol 28 and manufacturer's logo 24. It should be understood that the characteristics of laser 18 will vary depending upon the application.

Computer 20 is provided to control laser 18. Computer 20 may also be provided to control the ink applying means, such as applicator 14, and the information recording means, such as charge coupled device 24. Computer 20 may comprise any of a variety of commercially available personal computers sold by Dell Corporation of

Austin, Texas, having a microprocessor manufactured by Intel Corp. of

Phoneix, Arizona, and sold under the tradename "PENTIUM III" . Computer

20 operates under the control of a plurality of programming instructions (i.e., software). The programming instructions for computer 20 will vary depending upon the application of apparatus 10

(e.g., different control signals for laser 18 will need to be generated depending upon the composition of article 12 and the type of graphic 22 to be formed on article 12) . Such programming, however, is considered to be within the knowledge of one of ordinary skill in the art. Computer 20 generates a plurality of control signals used to control applicator 14 (or reels 32, 34), laser 18, and device 24.

Computer 20 may also receive signals generated by applicator 14, laser

18, and device 24, including informational signals from device 24 with respect to graphics 22 formed on articles 12 (discussed in greater detail hereinbelow) . Computer 20 may also include software for decoding the information signals as well as a memory 36 for storing information corresponding to graphic 22 such as the decoded information and an image of graphic 22.

Device 24 is provided to record an image of graphic 22 and to generate informational signals used to decode the information contained in graphic 22. Device 24 is conventional in the art and may comprise the charge coupled device manufactured by RVSI Acuity CiMatrix of Canton, Massachusetts, and distributed under the model number

CM4000. Device 24 captures a digital image of graphic 22 and may include a microprocessor operating under the control of software to interpret light/dark contrast areas and to generate informational signals responsive thereto. In one successful test of the inventive apparatus 10, device 24 operated in accordance with the following characteristics to capture an image of, and transmit information corresponding to, graphics 22 consisting of (i) a data matrix symbol

28 (measuring about 0.4375 square inches in size) and (ii) a data matrix symbol 28 and manufacturer's logo 24 (measuring about 1.25 square inches in size) on a glass vehicle windshield:

CHARACTERISTIC VALUE

Processor MX-500, HT-100

Camera Gain DEFAULT

Lens Type 701176 (RVSI)

Aperture 6.0 mm

Camera RSVI CM4000

Gamma 1.0, MGC , FRM

Focus Setting .06

Camera to Target Range 4-20 inches

It should be understood that a variety of other commercially available devices could be used to record information corresponding to graphic 22. For example, if graphic 22 includes a bar code, a conventional barcode reader could be uses that emits a laser and decodes the reflected portion of the beam to identify light and dark areas of the bar code .

Referring now to Figure 4, a method for inventory control of articles of manufacture will now be described. A method in accordance with the present invention may include the step 38 of applying an ink to at least a portion of a surface 16 of one of articles 12 As set forth hereinabove, the ink may be applied to surface 16 of article 12 in several ways. In a first embodiment of the present invention, step 38 includes the substep of spraying one or more coats of the ink onto surface 16 using a conventional spray applicator 14 (see Figure 1) . In a second embodiment of the present invention, step 38 includes the substep of positioning a carrier 30 on which the ink is disposed over at least a portion of surface 16 using reels 32, 34 (see Figure 2) .

A method in accordance with the present invention also includes the step 40 of directing laser 18 towards the portion of surface 16 of article 12 to which the ink has been applied. This action cures the ink and bonds the ink with, and embeds the ink in, surface 16 to form graphic 22 on article 12. Step 40 may be performed a predetermined period of time after step 38 has taken place to allow the ink to dry.

As set forth hereinabove, laser 18 may be directed m a predetermined pattern by computer 20 operating under the control of a plurality of programming instructions . The predetermined pattern m which laser 18 is directed is designed to impart a preselected graphic 22 on article 12. In a preferred embodiment, laser 18 is directed in a plurality of predetermined patterns with respect to an inventory of articles 12₁...12_n to impart unique, serialized graphics 22 on each article 12 within the inventory It should be understood, however, that laser 18 could be repetitively directed in the same predetermined pattern with respect to each of articles 12₁...12_n in order to impart the same graphic 22, such as a manufacturer's logo 24 and/or a patent number 26, on each article 12 (see Figure 3) .

The use of a computer-controlled laser 18 to cure the ink and to impart unique graphics 22 represents a significant improvement over conventional manufacturing and inventory control systems. In particular, the inventive apparatus and method enable unique identifiers to be imparted to each article 12 within an inventory of articles 12₁...12_n of manufacture in a high-volume, repetitive operation without the necessity for tooling changes. As a result, the inventive apparatus and method are more efficient and economical than known manufacturing and inventory control systems. The computer- controlled laser 18 also provides consistent marking and relatively high levels of resolution to the graphics 22 formed on the articles 12₁...12_n. Finally, the inventive apparatus and method allow application of a permanent, encoded identifier to articles of manufacture comprised of hardened nonporous materials without compromising the structural integrity of the articles.

A method in accordance with the present invention may also include the step 42 of cleaning the portion of surface 16 of article 12 to which the ink has been applied. The step may involve the use of a conventional solvent to remove all uncured and unbonded ink from surface 16 of article 12. Such solvents are conventional in the art and the particular solvent used will depend upon several factors including the type of ink used in the inventive apparatus and method. In some instances, the solvent used may even comprise water.

A method in accordance with the present invention may finally include the step 44 of recording information corresponding to graphic 22. As set forth hereinabove, a charge coupled device 24 may be used to capture an image of graphic 22 and to decode information regarding any unique serialized marking within graphic 22. Device 24 may then provide informational signals to computer 20 which stores the information obtained from the informational signals in memory 36. The use of a charge coupled device or other recording means in the inventive apparatus and method represents another significant improvement over conventional manufacturing and inventory control systems . Device 24 enables the inventive apparatus and method to both decode and decipher the data within graphic 22 while allowing transmission and storage of the data for improved inventory control. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it is well understood by those skilled in the art that various changes and modifications can be made in the invention without departing from the spirit and scope of the invention.

Claims

CLAIMSWe claim:

1. A method of inventory control for a plurality of articles of manufacture, comprising the steps of: applying an ink to at least a portion of a surface of a first article of said plurality of articles; and, directing a laser towards said portion of said surface of said first article in a first predetermined pattern to cure said ink and to bond said ink with, and embed said ink m, said surface and thereby form a first graphic on said first article.

2. The method of claim 1, further comprising the steps of: applying said ink to at least a portion of a surface of a second article of said plurality of articles; directing a laser towards said portion of said surface of said second article in a second predetermined pattern to cure said ink and to bond said ink with, and embed said ink in, said surface of said second article and thereby form a second graphic on said article, said second graphic different from said first graphic.

3. The method of claim 1, further comprising the step of applying a solvent to said portion of said surface to remove any uncured and unbonded ink .

4. The method of claim 1 wherein said article is comprised of a nonporous hardened material .

5. The method of claim 4 wherein said material comprises glass .

6. The method of claim 1 wherein said first graphic includes an identifier, said identifier unique among said plurality of articles.

7. The method of claim 1 wherein said article comprises a vehicle window.

8. A method of inventory control for a plurality of articles of manufacture, comprising the steps of: applying an ink to at least a portion of a surface of a first article of said plurality of articles; directing a laser towards said portion of said surface of said first article in a first predetermined pattern to cure said ink and to bond said ink with, and embed said ink in, said surface and thereby form a first graphic on said article; and, recording information corresponding to said first graphic.

9. The method of claim 8, further comprising the steps of: applying said ink to at least a portion of a surface of a second article of said plurality of articles; directing a laser towards said portion of said surface of said second article in a second predetermined pattern to cure said ink and to bond said ink with, and embed said ink in, said surface of said second article and thereby form a second graphic on said article, said second graphic different from said first graphic.

10. The method of claim 8, further comprising the step of applying a solvent to said portion of said surface to remove any uncured and unbonded ink.

11. The method of claim 8 wherein said article is comprised of a nonporous hardened material .

12. The method of claim 11 wherein said nonporous hardened material comprises glass.

13. The method of claim 8 wherein said first graphic includes an identifier, said identifier unique among said plurality of articles.

14. The method of claim 8 wherein said first article comprises a vehicle window.

15. The method of claim 8 wherein said recording step includes the substep of capturing an image of said first graphic using a charge coupled device.

16. An apparatus for inventory control of a plurality of articles of manufacture, said apparatus comprising: means for applying an ink to at least a portion of a surface of a first article of said plurality of articles and at least a portion of a surface of a second article of said plurality of articles; a laser; and, means for directing said laser towards said portion of said surface of said first article in a first predetermined pattern and towards said portion of said surface of said second article in a second predetermined pattern to cure said ink and to bond said ink with, and embed said ink in, said surface of said first article and said surface of said second article to thereby form a first graphic on said first article and a second graphic on said second article wherein said first graphic is different than said second graphic.

17. The apparatus of claim 16 wherein said first article is comprised of a nonporous hardened material.

18. The apparatus of claim 17 wherein said material comprises glass .

19. The apparatus of claim 16 wherein said first graphic includes an identifier, said identifier unique among said plurality of articles .

20. The apparatus of claim 16 wherein said first article comprises a vehicle window.

21. The apparatus of claim 16, further comprising means for recording information corresponding to said first and second graphics.

22. The apparatus of claim 21 wherein said recording means comprises a charge coupled device.

23. An article of manufacture, comprising: a substrate comprised of a nonporous hardened material, said substrate having a first surface; and, an ink graphic formed on said first surface by directing a laser towards a portion of said first surface to which an ink has been applied, said laser directed in a predetermined pattern to cure said ink and to bond said ink with, and embed said ink in, said surface and form said graphic.

24. The article of claim 23 wherein said material comprises glass .

25. The article of claim 23 wherein said graphic includes an identifier.