TW201208899A - Method and apparatus for reliably laser marking articles - Google Patents

Abstract

The invention is a method and apparatus for creating marks on an anodized aluminum specimen with selectable color and optical density. The method includes providing a laser marking system having a laser, laser optics and a controller operatively connected to said laser to control laser pulse parameters. The laser marking system is directed to produce laser pulses having laser pulse parameters associated with the desired color and optical density in the presence of a fluid directed to the surface of the anodized aluminum specimen while marking.

Description

201208899 VI. Description of the Invention: [Technical Field to Which the Invention Is Ascribed] The present invention relates to a laser marking of an anodized article (dized) by a laser processing system. In particular, the use of a laser processing system for an anodized article in a durable and commercially desirable manner. Specifically, it has a unique feature for making the interaction between the visible and infrared wavelength laser pulses of the Zibul ice and the passing articles, "Reliable 丄 = ground in the presence of the flow to establish a predetermined color and optics (4) Density) Persistence mark. [Prior Art] The products on the market are based on commercial, regulatory, decorative or functional purposes, and ten need to have some form of mark on them. The required marking characteristics include one, durability, and ease of application. Appearance refers to the ability to present reliably and reproducibly in a selected shape, color, and optical density. The persistence system is still able to maintain the same quality after the surface is worn out. The quality is still easy to apply. (10) The abiIlty of the abiIlty) has a programmable heart. And the cost of resources. However, the flatness means that the software is changed to a new one, and the hardware is not changed, such as a screen or a grass. The metal objects that have been anodized have a plastic shape and are resistant to sputum, and U is easy to be thrown first. Therefore, it is used in both industrial and commercial goods. Anodizing means any of a variety of electrolytic mirroring processes: where the natural oxide layer is proliferated at a temperature such as aluminum, titanium, zinc, 201208899 magnesium, niobium or tantalum. Above the metal to enhance resistance to corrosion or wear and to achieve decorative purposes. These surface laminates can be placed or dyed in any color to create a permanent, non-fading, durable surface on the metal. Many of these metals can be advantageously labeled using the features of the present invention. In addition, metals such as corrosion-resistant stainless steel can be marked in this manner. Many metal products such as these require permanent, clearly visible, commercially desirable markings. Anodized aluminum is a typical material with this need. Lasers generated by laser processing systems that have been anodized with aluminum lasers can be used to quickly create durable markings at a very low mark cost. Laser color changes have been made on the surface of anodized aluminum by laser pulses for many years. In a paper titled “Dry laser singular plus anodized aluminum” by p. Maja, M. Autric, P. Delaporte, P. Alloncle et al. (COLA, 99 5th International Conference 〇n Laser

Ablation (International Conference on Laser Ablation), July 1999 i9 23曰, G6ttingen 'Germany, published in Appl. Phys. A 69 [Suppl ], S343-S346 (1999), pp S43-S346), description from The surface of the aluminum is removed from the anodization zone, but it should be noted that 'the color change occurs where the laser energy is lower than the laser energy required to remove the anodization from the surface. One of the mechanisms by which k is used to explain the optical density or color change of a metal surface is the generation of laser-induced periodic surface microstructures (laser_in(juced peri〇die surface structures; UPSS). βΑ· γ. Vorobyev and Chunlei 201208899

Guo's paper "Colorizing meta" s with femt〇sec〇nd laser pulses (AppHed physics Letters 92, (〇41914) 2008, page to page 141 9 14 Page 3 Tian Shu can use the femt〇sec〇nd laser pulse to produce a variety of different colors on aluminum or aluminum-like metals. This paper describes the creation of black or gray markings on metals. Create a golden color on the metal. It also mentions some other colors, but not to mention them. LIpss is the only description provided for marking on metal surfaces. In addition, it only teaches or proposes to have 65 femtosecond timing pulses. Laser pulses of width to establish such structures. And, it does not mention whether the aluminum sample has been anodized or the surface has been cleaned prior to laser processing. The paper also does not discuss possible damage to the oxide layer. When discussing the duration of the laser pulse (durati〇n), the method of measuring the pulse duration should be defined. The timing pulse shape can be simple Gaussian pulse to more complex shapes associated with individual operations. Demonstrative non-Gaussian laser pulse mapping for specific type processing

In the U.S. Patent No. 7,126,746, issued to the assignee of the present disclosure, the assignee of the present disclosure is hereby incorporated by reference. Included in this article. This patent discloses a method and apparatus for generating a laser pulse having a typical Gaussian time waveform produced by a temporal profile different from a diode-pumped state (DPSS) laser. These non-Gaussian pulses are called, tailored "pulses, because their temporal pr〇file is generated by combining a pulse on 6 201208899 to produce a single pulse. ^ Pulses and / or first modulated pulses are modified from the typical Shans waveform. This produces a pulse whose pulse energy changes over time, typically containing - or multiple power peaks, wherein the instantaneous power increases from a small fraction of the pulse duration to a value greater than the pulse average power. Such tailored pulses can be useful in high rate processing materials that do not cause debris or overheating problems around the material. The problem is to measure the results of such complex pulses, such as those of complex pulses, which are basically applied to Gaussian pulses. The measurement of the Gaussian pulse duration is usually measured using the full width at _ maximum (FWHM) of the duration. In contrast, the integrator method, such as the US patent L〇NG ufe SILICA ULTRAViOLET OPTICAL ELEMENTS, which is described in No. M58,739, is invented by Memory, allowing complex timing. The shape is measured and compared in a more meaningful way. In this patent, it uses the following formula to measure the pulse duration (J nndif where T(1) is a function of the shape of the laser pulse timing. With regard to reliable and T-repetitively produced on the anodized Another problem with color and optical density marking is that the energy required to make extremely dark marks with a very easy to obtain nanosecond pulse width solid state laser is sufficient to cause damage to the anodization zone. This is an unacceptable result. Black 或 or Ming 7C degrees or color names are relative terms. A standard method of expressing color by quantity is the reference color metric (c〇1〇rimetry). This system is described in 〇hn〇, γ."CIE Fundamentais f〇rc〇i〇r 201208899

Measurements (CIE Foundation for Color Measurement)" (IS&T NIpi6

Conf, Vancouver, CN, October 16-20, 2000, pp. 540-545). Among the measurement systems, a black mark that meets commercial requirements is required to have parameters less than or equal to L*=40, a*=5, and b*=l〇. This produces a neutral black with no visible gray or chroma. In the United States number 6,777,〇98

Among the patents MARKING OF AN ANODIZED LAYER OF AN ALUMINIUM OBJECT (Knowledge of the anodized layer of aluminum objects), Keng Kit Yeo describes a method of marking an anodized aluminum article with a black mark. Located in a stack between the anodization zone and aluminum, it is as durable as an anodized surface. The indicia described therein are described as having a dark gray or black chroma and appear slightly less glossy than portions that have not been marked with nanosecond infrared laser pulses. In addition, it must remove all surface particles, for example, particles that remain after anodization after polishing. There are two reasons for making the mark according to the method requested by the patent. The first two steps are to establish a black mark that meets commercial requirements with a nanosecond pulse, which tends to cause damage to the layer; secondly, polishing or other processing The subsequent cleaning of the aluminum adds an extra step in the process to increase the associated costs and may interfere with the surface finish required for other processing. What is required, but not disclosed in the prior art, is a reliable and repeatable method of producing black or gray or colored markings on an anodized 1 'no need - expensive femtosecond laser or in process It is necessary to clean it if it interferes with the oxide layer or after the surface is ready. In addition, it does not provide a reproducible way to establish a variety of different colors for the 201208899 color on the anodized surface, nor does it thoroughly trace the discoloration or damage effects on the anodized layer. Therefore, it is necessary to propose a method for reliably and reproducibly establishing a mark having a predetermined optical density or gray color and color on an anodized film using a lower cost laser, which does not oxidize thereon. The object causes undesirable damage and does not require cleaning prior to anodization. SUMMARY OF THE INVENTION This heart is characterized by the addition of visible marks of various optical densities or gray scales and colors to anodized aluminum articles. These tags should be persistent and have a look that meets the needs of the quotient. This is achieved by the use of laser pulses to establish the marks, which are established at the surface of the aluminum below the oxide layer and thus protected by the oxide. These laser pulses establish a mark that meets commercial requirements without causing significant damage to the oxide layer, thereby rendering the marks durable. It establishes durable and commercially viable markings on anodized aluminum by controlling the laser parameters that generate and direct the laser pulses. In one feature of the invention, the laser processing system is configured to produce a laser pulse with appropriate parameters in a programmable manner. The use of a fluid flow to suppress the "injury" in the oxide layer during the marking of the laser allows the use of higher energy, which produces a greater range of color and optical density and higher throughput.示范Selective laser pulse parameters that select the reliability and repeatability of the 4-injection laser mark through anodization include laser type, wavelength, pulse duration, pulse repetition rate (repetiti〇n to (4), number of pulses , pulse month, pulse timing shape, pulse space shape and focal spot (f〇cal邛 size and shape. Further laser pulse parameters include the specified focal spot relative to the 201208899 ^ button surface and the pilot laser pulse The invention of the present invention is characterized by the use of a specific laser pulse depending on the number of specific laser pulses used to narrowly understand the color of the surface of the aluminum anodic aluminum from the optical density of the black eye. Other features of the demand "=3⁄4 month to create a variety of different optical density colors in brown or golden color 'depending on the specific laser pulse parameters used. Other features of the invention by dyeing or coloring The anodized zone is decolored or partially decolored, while the underlying aluminum is or is not labeled to pass through the anode oxygen A mark on the aluminum that is durable and meets commercial needs. Other features use a fluid flow during laser processing to reduce damage to oxides. To achieve the foregoing and other features in accordance with the purpose of the present invention, it is embodied and broadly stated herein. Form ' reveals a method for establishing a visible marker of color and optical density on an anodized Ilu sample, and a device configured to perform the method. The invention is for use in passing A method and a skirt for establishing a visible mark of color and optical density on an anodized sample, the method comprising providing a laser marking system having a laser, a laser optical module, and an effective connection to the mine a controller for controlling the parameters of the laser pulse and a controller having a parameter for storing the laser pulse, selecting a stored laser pulse parameter associated with a predetermined color and optical density, and guiding the laser marking system to generate an associated predetermined color and optical Laser pulse of density laser pulse parameters, while guiding a fluid flow when the item is marked 201208899 [Embodiment] The present invention features durable, selectively, predictably, and reproducibly labeled anodized aluminum articles with visible marks of various optical densities and colors. In an advantageous manner, it causes the indicia to appear on or near the surface of the aluminum and to keep the anodized layer substantially intact to protect the surface and the indicia. The 'a has been referred to as a mezzanine Institutional mark because it is made at or on the surface of the aluminum below the oxide layer forming the anodization zone. Ideally, the oxide remains intact after the mark is added to protect the mark and provide mechanical Adjacent to the surface between adjacent unmarked and unmarked areas. In addition, the marks should be able to be produced reliably and reproducibly, meaning that if a mark with a specific color and optical density is required, it is known to be a laser processing system. Processing the anodization will produce a set of laser parameters for a predetermined result. It should also be understood that some of the markings produced by laser processing systems are invisible. Among these features, the laser processing system establishes invisible marks under normal viewing conditions, but becomes visible when under other conditions, such as when illuminated by ultraviolet light. It should be understood that such indicia are used to provide anti-theft tags or other special indicia. One embodiment of the present invention uses a structured laser processing system to label anodized aluminum articles. An exemplary laser processing system that can be tuned to mark anodized aluminum articles is the ESI MM5330 micromachining system manufactured by Electr〇 Scientific, Inc., 97229' OR 'portiand. This system is a micromachined 201208899 system using a diode-excited Q-switched solid state laser with an average power of 5.7 W at 30 KHz pulse repetition rate and second resonance multiplication to 5 32 nm wavelength. Another exemplary laser processing system that can be tuned to mark anodized aluminum articles is also the ESI ML5900 micromachining system manufactured by Electro Scientific Industries, Inc., OR OR Portland, 97229. The solid-state diode-excited laser used in this system can be configured to emit a wavelength from about 355 nanometers (UV) to about 1064 nanometers (IR) at a pulse repetition rate of up to 5 Μ Η z. Any of the above systems can be configured to incorporate an appropriate laser, laser optical module, component handling device, and control software for use on an anodized surface in accordance with the methods disclosed in this specification. The marking is produced reliably and reproducibly. These modifications enable the laser processing system to direct laser pulses with appropriate laser parameters to a suitably positioned and placed anodized aluminum material at a predetermined rate and spacing to create a predetermined color and Marking of optical density. A schematic of one of the configured systems is shown in Figure 1. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of an ESI ΜΜ 5330 micromachining system constructed to mark articles in accordance with an embodiment of the present invention. The configuration includes laser 10'. In one embodiment of the invention, a diode-operated Nd:YV04 solid-state laser operating at a wavelength of i 064 nanometers, a Rapid model manufactured by Lumera laser GmbH of Kaiserslautern, Germany. unit. The laser selectively utilizes a solid-state resonant frequency generator to multiply the frequency to reduce the wavelength to 532 nm or to triple the frequency and reduce the wavelength to 355 nm to produce visible (green) or ultraviolet light, respectively ( Uv) Laser pulse. This laser 10 is rated to produce 6 watts of continuous power and has a maximum pulse repetition rate of 12 08 Hz 12 201208899. This Φ ά ... cooperates with the controller 20 to produce a laser pulse 12 having a duration of 1 picosecond to 1, and a lifetime of a pulse of 12 TV a - for four. These laser pulses I 2 can be applied to a special shape or by laser, and are tailored to allow for pre-existing. The laser depiction 14 cooperates with the controller 20 to actuate the pilot laser pulse 12 to create a laser spot 18 on or near the article 18 to be fixed. It includes a mobile control component 'operating in conjunction with the controller 14 to provide a composite shot - a special mode'. and ^ 0 1〇4 needle beam clamping capability. The composite beam positioning compensates for the relative motion of the flat 22, the laser spot 16, or both by the controller 20 guiding the steering member in the optical module 14 as the article 18 moves relative to the laser spot. Movement, the function of marking the shape above the item 18. "When the laser pulse 12 is piloted to form a laser spot 16 on or near the article 18, it is also laser-assisted by the laser. The laser optical module 14 controls the spatial shape of the laser pulse 12, which may be Gaussian or a special shape. For example, it can be: "top hat" spatial shape, which is delivered A laser pulse 12 having a uniform light shot dose throughout the illuminated spot. The spatial shape of a particular shaped shape such as this can be created using a diffractive optical member. The laser pulse 12 is also laser optical mode, group The photoelectric component, the cymbal control mirror member or the galvanometer member is gated or guided. The laser spot 16 is the focal spot of the laser beam formed by the laser pulse 12. As mentioned above, The laser energy distribution at the laser spot 16 depends on the optical module 14. In addition, the laser optical module 14 controls the depth of focus of the laser spot ^ 201208899, or the measurement plane is far away. The speed at which the spot is out of focus at the focal plane. Controlling the depth of focus, Control Benefit 20 can direct the laser optics module 14 and the platform 22 to repeatedly position the laser spot 16 at or near the surface of the article 8 with high precision. By positioning the focal spot at Marking above or below the surface of the article allows the laser beam to be out of focus to a certain extent, thereby increasing the area illuminated by the laser pulse and reducing the radiance of the laser at the surface. e Due to the geometry of the beam waist diameter is known Determining the focal spot above or below the actual surface of the article will provide further precise control over spot size and energy density. Figure 2 is a photomicrograph showing prior art Rays using no more than nanosecond pulses without fluid flow The shot is created on the anodized aluminum 3 。 mark. The anodized area shows a clear crack trace 32 ' in the marked area 34. A bad result. _ 3 shows the use of picosecond lasers in the same form: The same color and optical density mark 38' made on the anodized aluminum 36 shows no cracks. The picosecond laser strikes the anodized article. Add a black mark that meets commercial requirements without causing damage to the oxide layer. A commercially acceptable black material is a mark having (10) chromaticity L*=40, a* = 5j_b* = 1〇 or less. Another advantage of using a picosecond laser is that it is cheaper, requires less maintenance, and generally has a much longer operational life than prior art femtosecond lasers. Furthermore, the features of the present invention do not require anodization. The surface of the aluminum is cleaned prior to establishing the markings in accordance with commercial requirements. An embodiment of the invention performs the application of the marking on the anodizing under the anodizing zone. For the interlayer marking to be produced, the laser energy 14 201208899 The quantity density is defined as: F = E/s where E is the laser pulse energy and s is the laser spot area, which must satisfy fu<f<fs where the Fii substrate/coating interface is laser modified threshold value. In the case of aluminum/alumina, the Fs is the damage threshold of the surface layer or the anodization zone. Fu and Fs have been experimentally obtained and represent the energy density at which the selected lasers begin to damage the substrate and surface layer. For a 1 〇 picosecond (ps) pulse, the experiment shows that A1 (aluminum) Fu is ~12 joules/cm 2 for picosecond green light and ~0.2 joules/cm 2 for picosecond IR, while Fs is for picoseconds The green light system is ~0·18 joules/cm 2 and for picosecond IR it is ~丨 joules/cm 2 . Changing the laser energy density between these values produces markers of different colors and optical densities. Different pulse durations and laser wavelengths will each have a corresponding Fu and Fs value. The actual threshold for a particular set of laser parameters and the anodized material is determined experimentally. The advantage of using a fluid flow when marking is that the fluid flow increases the damage threshold Fs, thereby allowing the use of a higher capacity marker, which allows for higher throughput and a wider range of marker densities.

The consistent target of the present invention precisely controls the thunder at the surface of the aluminum article by adjusting the position of the laser spot from a surface located at the surface of the aluminum article to a clear distance above or below the surface of the aluminum article. Shooting energy density. Figure 4 shows a schematic of one of the beam waists of the laser pulse focal spot 40 and its vicinity. The beam waist diameter is represented by surface 42 which is the diameter of the spatial energy distribution measured by the fwHM 15 201208899 method on the optical axis 44 along which the laser pulse travels. The diameter 48 represents the laser pulse spot size on the surface of the surface when the laser processing system focuses the laser pulse at a distance above the s-surface (A-Ο). The diameter 46 represents when the laser processing system focuses the laser pulse. The size of the laser pulse spot on the surface of the aluminum at a distance (B-0) below the surface. In addition to the black color that meets commercial needs, it is also effective to apply a mark having a grayscale value to the article. Figures 5 and 6 show a series of gray scale marks applied to an anodized process by an embodiment of the present invention. The optical density of the mark ranges from almost indistinguishable to the background to all black. In accordance with one feature of the present invention, each grayscale marker can be represented as a unique ternary array of dE color metric values, L*, a*, and b*. One feature of the present invention combines each predetermined gray scale value with a set of laser parameters that reliably and reproducibly produce predetermined gray scale value marks on the anodized aluminum in accordance with the command. It should also be noted that indicia that may appear undetectable to the naked eye, when illuminated at frequencies other than broad-spectrum visible light, such as ultraviolet light, may become visible. Figure 5 shows black indicia 6, 62, 64, and 66 made on anodized aluminum 7 crucibles in accordance with one embodiment of the present invention. These marks 6(), 62, 64' and 66 have a range from less than L*=4〇, a*=5 and b*=i〇 to full moon-transparent CIE chromaticity' making it a mark of commercial need . The standard. Another feature is that 'because they are located under anodic oxidation without damage', they have a consistent appearance over a wide viewing angle range. The mark made by the prior art method tends to have a large difference in appearance with a change in the viewing angle due to damage to the anodized layer. 16 201208899 In particular, when marking with a prior art nanosecond pulse, apply sufficient laser pulse energy to the surface to make a dark mark to the yang+ damage, which causes the appearance of the mark to change with the viewing angle. % According to the present invention, no matter the color of the mark is 9, it does not damage the anodization angle of view and changes in appearance. These improved S are caused by the following laser parameters: Laser type

Spot size focus tfj deg. 0-5 mm, 4^: spacing 雷 for laser parameters of color and gray scale markings δ The optical density range of δ, 60, 62, 64, 66 is almost undetectable from unlabeled aluminum 60 to all black 66. The gray-white optical mobility 64, 66 between the two extremes is closer to the item by moving the focal spot: the raw @plus energy density produces a darker mark. The change in the directionality of the focal spot above the aluminum surface starts from zero, that is, the darkest optical density standard 6 2, j$, j^i increases from right to left by 64, 66 per mark 64, 66 increments, Gentleman φ 士士, ·, ° I is the lightest color mark 6 于 at 5 mm above the surface. 17 201208899 It is intended that the mark 64 produced by the focal spot of 4.5 to 1 _5 mm above the surface of the aluminum appears brown or golden yellow, while the marks 62 and 66 produced by the focal spot of one millimeter or less appear. Gray or black. Maintaining this precise control of the distance from the laser focal spot to the working surface plus maintaining other laser parameters within the tolerances of normal laser processing allows it to be fabricated on anodized aluminum to have a predetermined color and optical density Laser mark. In addition, the deepest color scale δ has shown a CIE chromaticity less than L*=40, a* = 5 and b* = 10, making it a black mark that meets commercial needs. Another feature of the invention determines the relationship between the indicia of the color outside the grayscale and the picosecond laser pulse parameters. Colors outside the grayscale can be produced in an anodized manner in two different ways. First, it can produce a golden hue in the range of optical density. This color is produced by making changes at the interface between the aluminum and oxide coatings. Careful selection of the laser pulse parameters will produce a predetermined golden color without damaging the oxide coating. Figure 5 also shows various colors of golden or brown produced by the features of the present invention. The laser marking of the anodized aluminum can also be achieved by the use of an IR wave laser pulse to mark the aluminum. This feature produces a mark of different gray scale densities by varying the laser energy density at the surface of the aluminum in a different manner. As described above, it is possible to create a gray scale by changing the energy density at the surface by placing the focal spot above or below the surface of the aluminum. The second way to control the gray scale is to change the total dose at the surface of the aluminum by changing the bite size or line spacing when marking the predetermined pattern. ...the spot distance refers to adjusting the rate of surface movement of the laser pulse beam relative to 18 201208899 or changing the pulse repetition rate or both: this results in a change in the distance between successive laser pulse impact locations. Changing the line spacing means adjusting the distance between the marked lines to achieve a variety of degrees of overlap. Figure 6 shows one of the arrays having a mark 72. Port 74. These indicia 72 are arranged in an array of six rows and four columns. : Six rows represent the upper surface of the aluminum range from 〇 (top column) to 5 mm (bottom column). Six: focal spot Z-direction height. The four columns represent the distance between the top, bottom 5, ι, and 〇 micrometers. It should be seen from Figure 6 that changing the 2-point height of the focal spot and changing the distance between the laser pulses can be produced in a predictable manner from less than -40, a* = 5, and b* = 1 〇 to nearly transparent. The gray scale ' between any predetermined optical density' thus produces an indication of compliance with the anodized. , 'rt & ----- — DPSS Nd: YV〇4 / anti-long T〇64nm-- version 1 knows the duration of time | 1 0 picoseconds 1SJ Ά — Shangs _., speech power 2.5 W -— Direct rate BQ Οτ- ----- ^00 KHz —— 50 mm/sec ~ this~II ------ 5 ' 10, 20, 50 μm Special spot size 5 5 -1 3 0 micron spot size ------ Gauss--- spread point ~~ two--- 〇- 5 mm' interval 1 mm per step Table 2: Laser pulse parameters for gray-scale IR marking can Applying a picosecond laser pulse to the anodized aluminum 19 201208899 - The second type of mark is a change in color contrast caused by the discoloration of the dyed anodized zone. On a microscopic scale, the anodization zone is porous and will readily accept many dyes. Referring again to Figure 3, this photomicrograph of anodized aluminum shows the porous nature of the surface. The laser pulse for marking the dyed anodized aluminum can be: depending on the wavelength and the pulse energy-producing region becomes transparent, the amount is removed, and the anodic oxygen is used to lower the aluminum underneath. The mark on it appears. Using a lighter density in the south, it is possible to simultaneously perform dye removal as well as aluminum under the anodized layer marked with black, grayscale or color as described in the previous paragraph. The lower energy pulse can partially remove the dyeing of the anodization zone, making it translucent, thereby locally coloring the underlying aluminum mark. Finally, longer wavelength pulses can be applied to the aluminum with a black or grayscale color that meets commercial requirements without causing discoloration of the anodization zone. Figure 7 shows the anodized aluminum article after dyeing, which is marked with visible (532 nm) laser pulses. Note that the dyeing in the anodization zone is removed in the region of the incoming laser pulse. Figure 8 shows that the same dyed anodized aluminum article has a mark made by IR (1〇64 nm) laser pulse. Note that the anodization zone is not discolored by the IR laser pulse, so it does not appear to cause the underlying aluminum color to cross the translucent state of the original oxide. Another feature of the invention relates to the application of a laser marking to anodized aluminum using a picosecond laser to pass a colored anodization zone. Since anodic oxidation usually forms a porous surface, it is possible to introduce a dye which changes its appearance. These dyes can be opaque or translucent, allowing a different amount of incident light to arrive at the mark and reflected back through the anodization zone. Figure 2 shows an anodized (4) article 8G having an array of indicia 82 having a pink coloration in the anodization zone in accordance with the present invention. The color is produced by removing the dye from the oxide layer, while the underlying aluminum exhibits a color from the original (silver) color to a series of laser-marked colors from brown to gray to black. These colors are produced by varying the energy density of the laser pulses at the surface. The four columns in the figure represent the change in the distance between the laser pulses from ίο. to 50 μm, while the line represents the change in the focal spot distance from the surface from 0.0 mm to 5.0 mm. These laser parameters in all cases result in the removal of the dye in the oxide covering the aluminum, allowing the markings on the inscription to be revealed. The laser marker optical density ranges from transparent to CIE chromaticity less than L*=40, a* = 5, b* = l〇. The laser parameters used to generate these markers are shown in Table 3. Laser type DPSS Nd: YOV4 — Wavelength 532 nm Pulse duration 10 picosecond pulse timing Shangsi laser power 4W repetition rate — 500 KHz — faint 50 mm / sec pitch 10. Micron spot size 10-400 μm spot size Suns focus height 0-5 mm Table 3: Laser parameters for visible oxide decolorization 21 201208899 Anodic oxidation zone dye removal is frequency dependent. As shown in Figure 7•, the 532 nm laser pulse removes the dyeing of the anodic oxidation zone even at the lowest energy density. On the other hand, the IR laser wavelength establishes a mark on the anodized after dyeing and does not remove the dye for most translucent dye colors. Figure 8 shows an anodized aluminum article 1 with a pink stain and a mark 102 made with IR laser pulses. The marks are made from translucent to black' and are modified by varying the distance from the focal spot to the surface and by varying the pitch to modify the laser energy density. The six rows in the figure represent the change in the distance between the laser pulse focal spot and the surface of the aluminum from 5.5 mm (right side) to zero (left side). The four columns in the figure represent the variation of the laser pulse spacing from 10 microns to 5 microns. The laser parameters used to generate these marks are shown in Table 4. Laser type DPSS Nd: YOV4 Wavelength 1064 nm Pulse duration 10 Saint seconds pulse timing Nanss laser power 4W Repeat rate 500 KHz Speed 5 〇 mm / sec pitch 1 〇 Micrometer spot size 10-400 μm Spot size 13⁄4 斯 focus Height 〇-5 mm Table 4: Laser parameters for ir-colored anodized zone markings for 532 nm (green) laser wavelengths of anodizing zone dyeing off 22 201208899 In addition, marking aluminum and ablating the surface The relationship between them is shown in Figure 9. For the 5 3 2 nanometer (green) laser pulse with the parameters given in Tables i and 3, Figure 9 shows the anodization decolorization (Fb) in joules per square centimeter (J〇ules/cm2). Mark the energy density threshold of aluminum (Fu) and surface ablation (Fs) under the anodization zone. In one aspect of the invention, the value of the 532 nm laser pulse is Fb = 〇1 joules/cm 2 , Fu = 〇13 joules per square centimeter, and Fs = 〇18 joules per square centimeter. The energy density threshold in joules per square centimeter of the 1 〇 64 nm (IR) laser pulse given the parameters given in Tables 2 and 4. In one aspect of the invention, the energy density threshold of Joules per square centimeter for a 1064 nanometer (lR) laser pulse is Fu = 〇 2 joules per square centimeter and Η 1.0 joules per square centimeter. Note that there is no threshold for the decolorization of the anodization zone because the IR wavelength laser pulse cannot begin to decolorize the anodization zone until the laser energy density is large enough to damage the covered anodization zone. It should also be noted that the exact values of Fb, Fu & Fs will depend on the particular laser and optical module used. For the specific processing configuration and the item to be marked, it should be determined experimentally and stored in the controller for later use. In still other embodiments of the invention, the programmable nature of the conditioned laser processing system allows the anodized aluminum article to be labeled with commercially desirable marking patterns. As shown in Figure u, in this feature, the two patterns are converted into a digital representation ι ΐ 2, which is decomposed into a number Λ 114 each of which contains a position or

The ^4's table does not have a color and optical density associated with each L 23 201208899 location. The list Π4 is stored in the controller 2〇. The controller 2 〇 connects each item 116 in the laser parameter linkage list 114 when the laser parameters are transmitted as commands to the laser 1 , optical module 14 and the mobile control platform 22 The laser emits one or more laser pulses that illuminate the surface 16 of the aluminum article 18 or its vicinity. These pulses will create a mark with a predetermined color and optical density. When the mark is being created, the laser beam 12 is moved relative to the aluminum article 18 in accordance with the position stored in the list such that the predetermined range of color and optical density marks are made in a predetermined pattern for anodization. Above the surface. In another embodiment of the invention, the colored anodized regions are patterned over previously patterned indicia to exhibit additional color and optical density. Among these features, the grayscale pattern is built on an anodized aluminum article. The article is then coated with a photoresist coating that can be developed by exposure to a laser pulse. After grayscale patterning and photoresist coating. The port is placed in the laser processing system and aligned for alignment so that the system can accurately apply a laser pulse to the map that has been applied to the item. The photoresist system used is called "negative" "resist, where the area exposed to the laser radiation will be removed' and the unexposed areas will remain on the item and continue to follow. The residual "protectively protects the surface of the article from being dyed, the anodized area where the towel has been exposed and then removed will be dyed with a predetermined color. (4) The polar oxide layer is designed to be translucent to allow light to pass through. The anodization zone reaches the underlying pattern and is reflected back through the anodization zone '(9) to produce a colored pattern having a selected color and optical density. This colored anodization zone can also utilize other features of the invention if desired 24 201208899 The technique is decolorized, and the product 4 has a predetermined color with a transparent transparency. This color can be applied to the entire area of the lower pattern, or in a point-by-point manner, which is limited only by the resolution of the laser system, usually Within ig to _ micrometer (4). This action can be repeated to produce the primaries of multiple colors. In the feature of the present invention, it is anodized in the form of multiple color overlapping grids. Color overlays, such as the Bell pattern (Β^_咖). By designing the grayscale pattern to match the color overlay grid, a durable, commercially available full-color image can be built on anodized aluminum. Above the article. Figures 12a through 12i show a series of steps for establishing such a color overlay using two colors. In Figure 12a, an aluminum article 118 has a permeation: anodized layer 120 and previously in accordance with the present invention. Other features are applied to the mark 122. A negative photoresist 124 is applied to the surface of the transparent anodized layer 12A. In Figure 12b, the laser pulse 126 exposes the regions 128, 13 of the photoresist 124. In Figure 12c, the unexposed photoresist 134 remains after the photoresist treatment, but the exposed photoresist is removed leaving the vacancies 132 in the treated photoresist layer 134. Figure 12d shows the underlying anodized layer The anodization region in the region 136 below the vacancy 132 in the treated photoresist layer 134 is colored in color. The intact photoresist layer 134 prevents the anodization region from being colored, except after treatment. Photoresist layer 134 Out of the region 132 that has been removed. Figure 12e shows the article 丨丨8 comprising a base anodization region 12 of the anodization region 136 having a color portion after removal of the treated photoresist layer and the previously applied indicia 122 Figure 12f shows an article 118 having a base anodization zone 12, comprising 25 201208899 color portion 136 and a second photoresist layer i 38. Figure 2g shows the second stack 1 38 of the photoresist being The laser pulse 142 is illuminated such that the region 140 is exposed. Figure 12h shows the article 1 丨 8 having the underlying anodization region 进行8 after the removal of the anodization region under the photoresist 140 and the removal of the residual photoresist 138 Happening. This causes the intact underlying anodized layer to contain colored regions 136, 144 overlying the previously marked regions 122. Figure 12i shows that subsequent laser pulses 146 are used to selectively decolorize the previously anodized and dyed portions of the aluminum article to produce an additional predetermined color or optical density. The process described in this feature of the present invention causes a color pattern to be overlaid on a gray scale pattern to produce a wide range of markers of durable and commercially desirable color and optical density in a programmable pattern. In another embodiment of the invention, a colored pattern of anodized regions can be created on the anodized aluminum article using a particular pattern to produce a full color image for viewing. Within this feature, a pattern representation of an image is applied to the surface using the techniques described herein. The colorants are introduced in the manner illustrated in Figures 12a through 12i, but the pattern in which the dyes are introduced into the anodized base layer is designed to convert the gray scale representation to full color. An example of this pattern is a Bell filter (Β _ 仙 ", not shown), which aligns the red, green and blue 遽 mirror elements in the - pattern so that the eyes are red, green and The perception of the blue element merges into a single-color associated with the gray-scale mark beneath the anodic oxidation zone of the colored anodized area, resulting in the appearance of a full-color image or pattern. The first resistance may be a negative or positive photoresist, and the pattern exposing the photoresist may be generated by a mask, such as in a circuit or semiconductor application, or directly written by an electronic device, or Direct deposition by techniques such as inkjet or direct burning of insects by laser. In another embodiment of the invention, a structured laser marking system 148 is shown in FIG. 13 and includes a nozzle 164 and a fluid supply 166. Figure 13 shows a modulated laser marking system ι 48 that includes a laser 150' laser 150 that emits a laser pulse traveling along a laser beam path 152, traversing the beam steering optics module (beamsteering() ptics) 154 Here, it is guided to illuminate an item 158 fixed to a mobile platform 162, all of which are controlled by a controller 16A. The nozzle 164 is supplied with fluid by the fluid supply ι 66 and is controlled to be located when the laser 丨 5 〇 is excited and pulsed along the laser beam path i 52 or a pulse is applied. The laser beam 152 illuminates an item 158 at or near the location. In some embodiments, the nozzle 164 is mounted to the mobile control device 170's control of the incineration controller 160 to move the nozzle i 64 relative to the article J 58 and thereby move the fluid flow 168 to direct the fluid flow 168 to Laser beam 152 is illuminated near the location on article 158. In other embodiments, the surface of the article 158 may be flooded by the fluid during laser processing, eliminating the need to cooperate with the laser beam 152 to move the nozzle 164. This fluid flow 168 cools the surface of the article and increases the amount of energy density that can be applied to the location on the item 158. This increases the Fs of the particular anodized aluminum article that is marked, thus allowing more energy density to be used to modify the surface of the aluminum at the interface of aluminum and oxide, while also allowing for greater energy density and thus Achieved greater production. Water is used as the fluid described above in this embodiment, however it is also possible to use air or other gases such as nitrogen or argon or other fluids. The purpose of the fluid flow on the surface is to prevent the temperature of the anodized zone from reaching the temperature at which the apparent damage begins. The rate of fluid flow that substantially lowers the temperature for a particular laser parameter is empirically determined and will vary with the fluid used and the associated heat transfer characteristics of the anodized and metallic articles. The manner in which fluid is delivered to the surface of the article as it proceeds is dependent on the fluid being used. If the fluid flow is a small stream of relatively high velocity fluid, such as air or inert gas, the nozzle 164 may have to be mechanically consuming to the beam steering optics module 154 to maintain the fluid flow 168 and the laser beam path 152. The cooperation between. In the case of a fluid such as water, the surface of the article can be flooded to provide thermal protection to a large area, in which case it is not necessary to move the nozzle 1 在 when the item i 58 is laser marked. This cooling effect allows for changes in the laser parameters used to establish the mark to allow for more intense color marking, greater anodic oxidation zone decolorization, and increased production' while limiting thermal damage to the anodized zone. Figure Ua shows an anodized article 18 crucible having a dyed anodization zone 182. A portion of the anodization zone has been subjected to laser decolorization 1 84 ' and results in a crack i % of the anodization zone. The laser parameters used are listed in Table 5. 28 201208899 Laser type DPSS Nd: YOV4 Wavelength 532 nm pulse #Continuation time 10 picosecond pulse timing Nansi laser power 2W repetition rate 200 KHz ~ speed 100 mm / sec pitch 10 micron - spot size 10-400 micron - spot Dimensions to S-focus South 0-5 mm Table 5: Laser thief color parameters in Figure 14a, which uses the laser parameters listed in Table 5 to decolorize the dyed anodization zone. In this embodiment, it selects the laser parameters to achieve high power, stable laser operation, and a marker rate that provides good system throughput. The focus height is then adjusted to provide fine control over the laser energy density. In this case, 〇.38 joules/cm 2 of winter laser energy is used to decolorize the anodized zone, which also produces cracks 1 86, which is unacceptable. For this particular sample, all energy densities in excess of 〇 u joules per square centimeter resulted in cracking of the anodization zone. Therefore, the anodized region of the sample of (4) cannot be efficiently decolored and does not cause cracks in the anodization region. Figure 14b shows the results of decolorization of the anodization zone using an embodiment of the invention, which also uses the laser parameters listed in Table 5. The anodized article 190 has been dyed 1 92 and a portion of 1 94 has been bleached in the presence of a fluid. Note 29 201208899 In this sample, although 〇2 S隹Ή· / τ is used能量·25 joules/cm 2 of energy density for decolorization treatment' but does not cause visible cracks. It avoids cracks by flooding the article with 2-3 mm of water during laser bleaching. DETAILED DESCRIPTION OF THE INVENTION The well-used laser parameters include the use of lasers having wavelengths ranging from 汛 to uv, particularly from about 106 microns to about 3^5 nm. The laser operates at 2%, basically at i The preferred embodiment among the ranges of _w is from ^ to i2w. The pulse duration ranges from ! picoseconds to daiseconds (four), or the preferred embodiment is from i picoseconds to nanoseconds. The laser repetition rate is in the range from kHz to 100 kHz, and preferred embodiments are from ι〇KHz to 1 MHz. The laser energy density ranges from approximately χ1 χ1〇.6 joules/ Square centimeters to 100.0 joules per square centimeter, or especially from 1〇χ 1 • 2 joules per square centimeter to 10.0 joules per square centimeter. The speed at which the laser beam moves relative to the marked item ranges from 丨 mm/sec to 1 〇 m/sec, or a preferred embodiment is from 100 mm/sec. Up to i m/s. The spacing or spacing between adjacent columns of laser pulses on the surface of the article ranges from 1 micron to 1 micron, or preferably from 10 micron to 1 micron. The measured laser pulse spot size ranges from 1 〇 micron to 1 〇〇〇 micron, or preferably from 50 micron to 500 micron. The laser pulse focal spot position relative to the surface of the article ranges from _ 10 Mm to + i 0 mm, or in particular from 〇 to + 5 mm. The details of the foregoing embodiments can be modified without departing from the basic principles of the invention, which should be apparent to those skilled in the art. The scope shall therefore be defined by the scope of the following patent application. 201208899 [Simple description of the diagram] Figure 1. Laser processing system. Figure 2, Marked by the prior art nanosecond pulse system. Figure 3, Marked by the second pulse. Figure 4. Beam waist diameter. Figure 5. Gray scale mark on anodized aluminum. Circle 6, on the anodized aluminum. Figure 7 'Dyeed Adding the anodized aluminum to the visible mark, Figure 8, and the anodized aluminum with the IR mark, Figure 9, shows the relationship between the threshold of the visible laser pulse. Figure 10 shows the IR laser pulse. The relationship between the threshold values, that is, the image data converted into laser parameters. Fig. 12a - i ' applied to the colored anodized area of an aluminum article. Figure 13. Laser processing system with fluid flow. Figure 14a 'Decoloration of the anodized zone shows cracks. Figure 14b Decolorization of the extreme gasification zone shows no cracks when using fluid. [Main component symbol description] 10 Laser 12 Laser pulse 14 Laser optical module 16 Laser spot 18 Item 20 Controller. 22 Platform 31 201208899 30 Anodized aluminum 32 Crack 34 Marked area 36 Aluminized aluminum 38 Mark 40 Focal spot 42 Beam waist surface 44 Shaft 46 Diameter 48 Diameter 60-66 Mark 70 by 'anodized aluminum 72 Mark 74 in Lu goods 80 Selected items 82 Marked 100 Anodized aluminum Item 102 Mark 110 Pattern 112 Digital representation 114 List 116 Item 118 in the list Transparent material 120 transparent anodized layer 32 201208899 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 152 154 158 160 162 164 166 168 Marking photoresist layer Laser pulse resisting area Photoresist area Photoresist layer in the photoresist layer under the vacancy layer Second resist layer Second area in the second photoresist layer Laser pulse colored area Colored area laser Marking system laser laser beam path beam steering optical module item controller mobile platform nozzle Fluid supply fluid flow movement control 33 170 201208899 180 Anodized article 182 Abatted anodized zone 184 Laser decolored zone 186 Crack 190 Anodized article 192 Stained zone 194 Fluid is present Decolorization zone Fb Anodization zone energy density threshold value · value Fu Marked the energy density of aluminum under the anodization zone Threshold value Fs Surface energy density threshold of burnt exposure 34

Claims (1)

201208899 VII. Patent Application Range: 1' A method for establishing a mark having a predetermined property on an anodized article, comprising: providing a laser marking system with programmable laser pulse parameters and anodizing the same Providing a fluid on the treated article; determining a characteristic laser pulse parameter associated with establishing the mark having the predetermined property in the presence of the fluid; and directing the laser marking system to locate the fluid at the passage Determining the anodized article by using the determined specific laser pulse parameter on the anodized article, thereby establishing a method having the predetermined property of the mark i terminology of the mark The anodized article is anodized aluminum. 3. The method of claiming a "page, wherein the predetermined property comprises a size 'shape, position, color, and optical density. 4. The method of claiming a pulse width, a wavelength energy density, a spot size, and a first term, wherein the laser pulse parameter, the number of pulses, the pulse timing shape, the pulse spot shape, and the focal spot. 5. The method of claim 1, wherein the system water. 6. The method of claim 1, wherein the fluid is provided in a flow-through manner. The method of claim 6, wherein the fluid flow is relative to the beta metaphys. Mouth movement to maintain a relationship between the fluid and the laser pulse. 0 35 201208899 8. The method of claim 2, wherein the marking is by dyeing and selectively decolorizing the anodized article The method of claim 4, wherein the pulse width ranges from about 1 picosecond to about 〇〇〇 nanosecond. 10. The method of claim 4, wherein the wavelength ranges from about 10.6 microns to about 355 nm. 11. The method of claim 4, wherein the number of pulses ranges from 1 to about 1 〇 〇 〇 pulses. 12. The method of claim 4, wherein the pulse timing shape is Gaussian. 13. The method of claim 4, wherein the pulse timing shape is tailored. 14. The method of claim 4, wherein the pulse energy density ranges from U x 1G, ear/square centimeter to ι joule/square centimeter. The method of claim 4, wherein the circumference of the range is from about 10 micrometers to about 丨〇〇〇, wherein the spot size is micrometers. The method wherein the spot shape is one of a Gaussian or shaped shape as in claim 4 of the patent application. The method of claim 4, wherein the focal spot is focused on one of the surface of the anodized article, above or below the surface. 18. The method of claim 3, wherein the predetermined optical density 36 201208899 degrees is equal to or less than about L*=4〇, a*=5, and b*=i〇. 19. The method of claim 3, wherein the color is white, black, transparent, gray, and AA~1 is not brown (tan) or gold (gold). a device for producing a laser mark having a predetermined property on an anodized article, comprising: a laser 'for generating a laser pulse; a laser optical module for modifying and guiding Controlling the laser pulse; a platform 'for carrying and positioning the anodized article; a fluid for absorbing heat from the anodized article; and a controller for accessing the specific laser The pulse parameter is coordinated with the laser, the laser optical module, and the platform, and the laser pulse is generated and guided according to the specific laser pulse parameter to illuminate the anodized article, and the fluid is from the raft Vortex ▲ The anodized article absorbs the heat generated by the laser pulse to produce the mark having the predetermined property. &A device as claimed in claim 20, wherein the anodized article is anodized aluminum. 22. The apparatus of claim 2, wherein the predetermined property comprises a size, a shape, a position, a color, and an optical density. 23_ The device of claim 2, wherein the laser pulse width, wavelength, number of pulses, pulse timing shape, pulse radiance, spot size, spot shape, and focal spot. A device of the second aspect of the patent, wherein the system water is used. 37 201208899 25. The device of claim 2, wherein the fluid is provided in a flowing form. 26. The rupture of claim 25, wherein the fluid flow is moved relative to the article to maintain a relationship between the fluid and the laser pulse. 2' The device of claim 20, wherein the marking is produced by dyeing and selectively decolorizing the anodized article. 28. The scope of the device of claim 23 is Approximately 1 picosecond to about 1 nanosecond. 29. The seismic perimeter of claim 23 is from about 10.6 microns to about 35 5 nm. 30. The device as claimed in item 23 of the patent scope ranges from 1 to about 1 pulse. 31. The device shape as in claim 23 is Gaussian. 32. The shape of the device as claimed in item 23 of the patent application is tailored. 33. If you apply for the patent scope of item 23, and set the I ee邙 team 1SJ month & J density of IlL enclosure from I.0 X 1 〇·6 隹 ear / gentleman \ ,,,, bucket / thousand Centimeters to 1 〇. 〇 joules / flat ^ cm. 34. As claimed in claim 23, wherein the spot size τ ranges from about 10 microns to about 1 inch. 35. The method according to claim 23, wherein the spot shape method is wherein the pulse width is a range of the wavelength of the pulse number, wherein the pulse timing is the pulse time period, wherein the pulse time piece of the pulse energy can be j 38 201208899 One of the shapes of the shape or shape of the β 3 6 female Q patent, wherein the focal spot is focused on the surface of the article in the anode gas, above or below the surface. one. Device, wherein the predetermined optics #=5 and b*=10. If the density of the 22nd item of the patent application is equal to or less than about L*=40, a ^ * claim 22, the predetermined color is white black, transparent, gray, tan or golden yellow. One of them. 39. For a device having a patent range of 帛20 g, the mark is produced by dyeing and selectively decolorizing the anodized article. The apparatus of claim 20, wherein the laser parameter is selected to produce the indicia on the anodized article in a predetermined pattern having a different optical density to form an image. 41. The device of claim 40, wherein the anodized region is exposed by selective removal of a photoresist layer and dyed, and the exposed, dyed anodized region is selectively decolored And applying the colored anodized region to the image to produce a color image. Eight, the pattern: (such as the next page) 39