TW201208897A - Method and apparatus for reliably laser marking articles - Google Patents

Abstract

Disclosed is a method for creating a mark desired properties on an anodized specimen and the mark itself. The method includes providing a laser marking system having a controllable laser pulse parameters, determining the laser pulse parameters associated with the desired properties and directing the laser marking system to mark the article using the selected laser pulse parameters. Laser marks so made have optical density that ranges from transparent to opaque, white color, texture indistinguishable from the surrounding article and durable, substantially intact anodization. The anodization may also be dyed and optionally bleached to create other colors.

Description

201208897 VI. Description of the Invention: [Technical Field to Which the Invention Is Ascribed] The present invention relates to laser marking of an anodized article. In particular, it relates to the use of a laser processing system to mark an anodized article in a manner that is durable and commercially desirable. Specifically, it has a unique feature of making the interaction between ultraviolet, visible, and infrared wavelength lasers and anodized articles' features to reliably and reproducibly build on anodized articles. A white mark that is persistent and meets commercial needs. [Prior Art] Products on the market are often based on commercial, regulatory, decorative or functional purposes and often require some form of marking on them. The desired marking characteristics include the external % of the crucible and the ease of application. Appearance refers to the ability to reliably and reproducibly select the shape, color, and optical density (_eai exhibits the mark. Persistence is the wear of the marked surface.) Refers to the cost of material, time, and f-sources that are marked with programmability. Programmability refers to programming a marking device with a new pattern to be marked by changing the software, rather than changing such as a screen or A hardened body such as a mask. The anodized metal object is light, strong, easy to shape, and has a durable surface finish. Therefore, there is a midnight application of anodizing in industrial and commercial goods. Any of the processes in which - the natural oxide layer is proliferated on a metal such as aluminum, titanium (ti - 201208897 zinc, magnesium, niobium or tantalum) to enhance the corrosion or wear Resistance and the purpose of decoration. These surface laminates can in fact be colored or dyed to create a permanent, non-fading color on the metal. Long-lasting surfaces. Many of these metals can be marked efficiently using the features of the present invention. In addition, metals such as corrosion-resistant stainless steel can be labeled in this manner. Many metal products such as these require A permanent, clearly visible mark that meets commercial needs. Aluminized aluminum has a typical material for this requirement. Laser color changes have been made on the surface of anodized aluminum articles. For many years, in a paper titled “Dry laser cleaning of anodized aluminum” by p. Maja, M. Autric, P. Delaporte'P. Alloncle et al. (COLA'99 -5th International Conference on Laser

Ablation (International Conference on Laser Ablation), July 19-23, 1999, GSttingen, Germany, published in Appl. Phys. A 69 [Suppl·], S343-S346 (1999), pp S43-S346), Describe the removal of the anodization from the surface of the aluminum 'but it should be noted that its 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 proposed to explain the optical density or color change of the metal surface is the generation of laser-induced periodic surface structures (LIPSS). Α_ Υ·Vorobyev and Chunlei Guo's paper "Colorizing metals with femtosecond laser pulses” (AppUed physics 201208897)

Letters 92, (041914) 2008, pages 41914-1 through 141914-3) descriptions can be fabricated on aluminum or aluminum-like metals using femt〇sec〇nd laser pulses Out of a variety of different colors. This paper describes the creation of black or gray markings on metal and the creation of a golden color on the metal. It also mentions some other colors, but it is not mentioned. Lipss is the only description provided for marking on metal surfaces. Moreover, it only teaches or suggests laser pulses having a pulse width of 65 femtoseconds to establish such structures. And it does not mention whether the sample is anodized or the surface has been cleaned before laser treatment. Nor does the discussion discuss possible damage to the oxide layer. Continued When discussing the duration of a laser pulse (durati〇n), the method of measuring the pulse duration should be defined. Timing pulse shapes can range from simple Gaussian pulses to more complex shapes associated with individual operations. An exemplary exemplary non-Gaussian laser pulse for a particular type of processing is described in US Patent GENERATIN No. 7,126,746 (3 sets 〇f TAIL0RED LASER PULSES (in the production of a tailored laser pulse group) inventor Sun The patent is assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety in its entirety in its entirety in the the the the the the the the the the ; DPSS) methods and apparatus for laser pulses of typical Gaussian time waveforms produced by lasers. These non-Gaussian modes of pulses are called, (4) tailored "pulses' because their time waveforms are combined by More than one pulse is generated to produce a single pulse and/or a photoelectrically modulated pulse that changes from a typical Gaussian waveform. This produces a pulse whose pulse energy changes over time 'usually containing a 201208897 or multiple power peaks,婵加到—where the instantaneous power is rushed in a small part of the pulse duration. The value of the fan == average power The problem is that the srr/35 heat problem is around. The problem is that the metrics such as the duration of the complex pulses can be measured using the indicia t, ± _ Θ ^ γ which are basically applied to the high pulse. The measurement of the duration of the Muse pulse is usually the use of the duration of the half-peak full-scale θ value of the width at half maximum; FWHM), 'J relative to this, using the integral flat method, as described in the number ό, 058, 739: The US patent L〇NG LIFE FUSED SILICA ULTRAVIOLET CAL· ELEMENTS (the long-life fused silica optical component) Mao Mingren M〇rton et al. 'allow complex timing shapes to be measured and compared in a more meaningful way. In this patent, it measures the pulse duration using the following formula where T(t) is a function of the shape of the laser pulse timing. About the reliable and reproducible generation of eight on the anodized aluminum Another problem with the marking of color and optical density is that the energy required to make very dark marks with a nanosecond pulse width solid state laser that is readily available is sufficient to cause damage to the anodization zone. An unacceptable result., Darkness or "brightness" or color name is a relative term. A standard method of measuring the color of a quantity is a reference color measurement (c〇1〇rimetry) cIE system. This system is described in 〇hn〇, .Y·MCIE Fundamentals f〇rc〇1〇r 201208897

Measurements (CIE basis for color measurement)·' in the article (is&t NIP 1 6 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, &*=5, and b*=l〇. This produces a neutral black 8 with no visible grayscale or chroma. In the US patent MARKING OF AN ANODIZED LAYER OF AN ALUMINIUM OBJECT No. 6,777,098, the inventor Keng Kit Yeo describes a The black mark marks the anodized aluminum article, which is located in the stack between the anodization zone and the aluminum, and thus is as durable as the 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 of aluminum, for example, particles that remain after anodization after polishing. There are two reasons for the disadvantages of marking according to the method sought by the patent: First, the creation of a black mark that meets commercial requirements with a nanosecond pulse tends to cause damage to the oxide layer; secondly, polishing or other processing The subsequent aluminum/moon cleaning adds additional steps to the process, adding to the associated costs and possibly interfering with the surface finishes required for other processing. What is required, but not disclosed in the foregoing, is a reliable and repeatable method of producing black, white or gray or colored markings between the anodized aluminum, which does not require expensive femtosecond lasers. Or it may interfere with the oxide layer during the process or after the surface is ready. In addition, it does not provide information on how to reproducibly create various colors on the surface of anodized aluminum 201208897, nor does it thoroughly trace the discoloration or damage effects on anodized sheets. Therefore, it is necessary to propose a method for reliably and reproducibly establishing a mark having a predetermined optical density or gray scale and color on anodized aluminum using a lower cost laser, which does not cause oxides thereon. Poor damage and no cleaning required before anodizing. SUMMARY OF THE INVENTION One feature of the present invention is the addition of visible white markings of various optical densities to anodized aluminum articles. These markings are durable and have an appearance that meets commercial needs. This is achieved by establishing the markers using a laser marking system. These marks are built into or under the oxide layer and are therefore protected by oxides. These laser pulses establish a mark that conforms to the quotient = demand and do not cause substantial damage to the oxide layer, so that: the standard: remembers durability. It establishes durability and meets commercial requirements by controlling the generation and guidance of the laser parameters of the laser pulse. In one feature of the invention, the laser processing system is configured to produce laser pulses with appropriate parameters in a programmable manner. Optional to improve the reliability of laser marking through anodization and: = two exemplary laser pulse parameters including laser type, wavelength, pulse only, B pulse repetition rate (repetition me), number of pulses, pulse = pulse timing shape, pulse space shape, and focal spot size and shape. Into the cow is not 6 丄 The surface of the object, the parameter contains the specified focal spot relative to and the relative motion of the guided laser pulse relative to the object I. 9 201208897 The present invention is characterized by the use of a specific laser pulse parameter depending on the specific laser pulse parameters used to make the oxide layer of the upper layer of the metal article white from an optical density that is almost imperceptible to the naked eye, thereby establishing durability and meeting commercial needs. . Other features of the present invention are achieved by dyeing or tinting the anodizing zone: de-coloring or partial discoloration, while adding or not labeling the underlying aluminum to establish durability and commercial requirements on the anodizing process. Marked. Another feature of the present invention is to establish a slight change in the size of the anodized layer of the scattered light 'and to create a slight "creamy" or diffuse appearance to the appearance without completely removing the anodized region Opaque, bright, different from the & appearance. In order to achieve the foregoing and other features in accordance with the purpose of the present invention, a method for establishing a color and optical density selectable visible mark on an anodized aluminum sample is disclosed in the form embodied and broadly recited herein. The configuration to perform the method [the feature of the present invention is to create visible indicia of selectable color and optical density on the anodized article. The method includes providing a laser marking system having a laser, a laser optics, a controller operatively coupled to the Xiaolei shot to control laser pulse parameters, and a controller having stored laser pulse parameters Selecting a stored laser pulse parameter associated with a predetermined color and optical density, and directing the laser marking system to generate a laser pulse having a laser pulse parameter associated with a predetermined color and optical density, the method comprising greater than about 丨 picoseconds and less than The large I spoon has a timing pulse width of 1000 nanoseconds, or a continuous wave (CW), to illuminate the anodized aluminum. 10 201208897 [Embodiment] Embodiments of the present invention are durable, selectively, predictably, and reproducibly visible in various optical densities and colors: anodized aluminum article. In an advantageous manner, it is such that the marks appear on or near the surface of the aluminum or in the anodization zone and maintain the anodized layer substantially intact to protect the surface and the indicia. The mark made by this method is called a sandwich mark because it is formed at or on the surface of the aluminum under the oxide layer forming the anodization region, or within the oxide layer itself. The T embodiment of the present invention maintains the surface of the oxide substantially intact after labeling to protect the target: a mechanically contiguous surface between adjacent labeled and non-marked regions. The tactile sensation of the human body is substantially indistinguishable from the anodized area of the surrounding mark for the texture of such marks. In addition, the marking of the material should be sinful and reproducible, meaning that if a marking of a particular color and optical density is desired, it is known that when the anodized aluminum is treated by a laser processing system, a predetermined result will be produced. A set of laser parameters. It should also be understood that, in some cases, the white mark created by modifying the anodized layer by laser treatment may be further processed by adding a fluorescent or phosphorescent dye to the anodized region, possibly before laser processing. Or afterwards. One embodiment of the present invention uses a structured laser 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 (micromachining syStem) manufactured by Electro Scientific Industries, Inc., 97229 'OR, Portland 〇201208897 This system is written in ESI's "Model 5330ns Service"

Guide (5 3 30ns Model Service Guide), ESI P/N 178987a, 2009, 1 month, which is incorporated by reference in its entirety. This system uses a diode-excited Q-switch solid-state laser. A micromachining system having an average power of 5.7 W at a pulse repetition rate of 3 kHz and a second resonance doubling to a wavelength of 532 nm. The other can be tuned to represent an exemplary mine for anodized aluminum articles. The ESI ML5900 micromachining system is also manufactured by Electro Scientific Industries, Inc., 97229, 〇R, p〇rtland. This system is written in ESI"Model 5900

Service Guide (5900 model service guide, ESI p/N! 78472A, October 2009, which is incorporated by reference in its entirety. The solid-state diode-excited laser used in this system can be grouped up. A wavelength of from about 355 nanometers (uv) to about 1 〇64 nanometers (IR) is emitted at a pulse repetition rate of 5 MHz. Any of the above systems can be added by adding appropriate laser and laser optical modules. The component handling device and the control software are configured to reliably and reproducibly produce markings on the surface of the anodized aluminum in accordance with the method disclosed in this specification. These modifications enable the laser processing system to be predetermined The laser pulse with appropriate laser parameters is guided to a properly positioned and placed anodized aluminum article at a rate and spacing to create a mark having a predetermined color and optical density. A schematic diagram of an ESI MM5330 micromachining system configured to mark an article in accordance with an embodiment of the present invention. The configuration includes a laser, which operates in an embodiment of the present invention. 064 nm wavelength dipole excited Nd: YV04 solid state laser, by German 仏 (four) coffee (10) 12 201208897

He is the owner of the Lumera laser GmbH, the J Kapid type. The laser selectively multiplies the material by a solid-state (four) frequency generator to reduce the wavelength to 532 nm or to triple the frequency and reduce the wavelength to 3 55 nm. ) or ultraviolet (uv) laser pulses. This laser 10 is rated to produce 6 watts of continuous power with a maximum pulse repetition rate of ι〇〇〇 κΗζ. This laser 1G cooperates with the control (4) 2G to produce a laser pulse 12 having a duration of 1 picosecond to 1, GGG nanosecond. These laser pulses 12 may be Gaussian or specially shaped or tailored via the laser optics module 14 to allow predetermined marking of the force applied. The laser optical module cooperates with the controller 2G to guide the mine. The squirt 12 forms a laser spot 16 on or near the article 18. The article 18 is secured to the platform 22 'which contains the mobile control member' with the controller 2 and the laser optics: Group 14 operates in conjunction To provide a composite beam position. The composite beam positioning system compensates the platform by causing the controller 2 to guide the steering members in the laser optical module 14 when the article i" moves toward the laser spot 16 22. The relative motion induced by the laser spot 16 or both to mark the shape above the item 18. When the laser pulse 12 is controlled to A 0 0 t. When the laser spot 16 is formed in the vicinity thereof, the laser optical module 14 is also matched with the controller core to shape the space. The laser optical module 14 controls the spatial shape of the laser pulse 12, and the seal is S-shaped or special-shaped. Shape of the plastic. For example, it can use the " == formula (top hat ): The topography 'delivers a laser pulse 12 with a uniform (four) dose in the entire spot that illuminates the marked object. The morphological shape of a special shaped shape such as this can be made using a diffractive optical component 13 201208897 The laser pulse 12 can also be gated or controlled by a photoelectric component, an steerable mirror component or a galvanometer component in the laser optics module 14. The laser spot 16 is a laser pulse 12 The focal spot of the formed laser beam. As previously mentioned, the laser energy distribution at the laser spot 16 is dependent on the laser optics module 14 ^ In addition, the laser optics module 14 controls the depth of focus of the laser spot 16 (depth of focus) 'Or the speed at which the spot is out of focus when the measurement plane is away from the focal plane. By controlling the depth of focus, the controller 20 can guide the laser optical module 14 and the platform 22 to be repeatedly Highly accurate positioning of the laser spot 16 at or near the surface of the article 18. By placing the focal spot above or below the surface of the article to make a mark allows the laser beam to be out of focus to a certain extent, thereby increasing the laser Pulsed irradiation The domain also reduces the laser energy density at the surface. Since the geometry of the beam waist diameter is known, determining the focal spot above or below the actual surface of the article provides further precise control of spot size and energy density. Figure 2 is a photomicrograph showing the creation of a mark on anodized aluminum 30 using a prior art laser having a pulse of greater than one nanosecond. The anodization zone shows a clear crack trace 32 in the marked area 34, A poor result. Figure 3 shows the same color and optical density mark 38 made by the picosecond laser on the same form of anodized aluminum 36, with no cracks. The picosecond laser has a black mark on the anodized aluminum article's commercial requirements and has not caused damage to the oxide layer. A commercially acceptable black color is defined as a mark having a CIE chromaticity L*=4〇, 3 and bH!==10 or less. Another advantage of using picosecond lasers in 201208897 is that it is cheaper, requires less maintenance, and generally has a much longer operating life than prior art femtosecond lasers. The surface of the aluminum is cleaned prior to oxidation to create a marking that meets commercial needs. μ An embodiment of the invention performs the application of a mark on the anodized aluminum under the anodization zone. For the generation of the interlayer mark without harming the anodization zone, the laser energy density is defined as: F = E / s where E is the laser pulse energy and s is the laser spot area, must be full F < Fs, where the Fu substrate The laser modifies the threshold value. In this example, the substrate is aluminum, and the Fs is the damage threshold of the surface layer or the anodized region. Fu and Fs have been experimentally obtained and represent the measured imperfections of the selected laser to cause the substrate and the surface to begin to lose. For the i 〇 picosecond (ps) pulse, the experiment shows that Al (|g) of Fu is for picosecond green light ~ 〇 13 joules / cm ^ 2 (j / cm 2 ) and for picosecond IR is ~ 〇 · 2 joules / square centimeter, while Fs is ~0.18 joules / square centimeter for picosecond green light and ~丨 joules per square = cent for picosecond IR. 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 homing values for a particular set of laser parameters are determined experimentally. An embodiment of the present invention precisely controls the position of the laser spot by changing the position of the laser spot from a surface located at the surface of the article to a position above or below the surface of the aluminum at a distance of 15 201208897 The laser energy density at the surface. Figure 4 shows a schematic representation of the beam waist diameter of the laser pulse focal spot 4 〇 and its vicinity. The beam waist diameter is represented by a surface 42 which is the diameter of the spatial distribution of the laser pulse measured by the FWHM method on the optical axis 44 along which the laser pulse travels. Diameter 48 represents the size of the laser pulse spot on the surface of the aluminum when the laser processing system focuses the laser pulse at a distance (A_〇) above the surface. Diameter 46 represents the size of the laser pulse spot on the surface of the aluminum when the laser processing system focuses the laser pulse at a distance (Β·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 anodized aluminum by the present invention - examples. Mark to all black. According to the present invention, the optical density range of the CIE color metric is indistinguishable from the background, and each gray scale mark can be characterized by one of the features of the present invention, each of which is reliable according to the command and unique to the numerical value. a set of elements, L*, a*, and b*, - a predetermined grayscale value that links a set of laser parameters,

The predetermined gray scale value mark can be repeatedly produced on the anodized aluminum emulsified aluminum. It should also be noted that the mark, which may appear undetectable to the naked eye, becomes ultraviolet light when it is illuminated at a frequency other than wide-area visible light to become visible. The black marks 60, 62, 64 from the anodizing & υ / υ are taken as β a 4 · and 66. These indicia 60, 62, 64, and 66 have CIE chromaticities ranging from less than a = a 5 and b * = 10 to full transmissive, making them a mark consistent with the τ port. The mark 16 201208897 % of the extreme oxidation zone appearance. The damage of the polar oxide layer is very different. When an anodic oxidation zone is applied, the anodic oxidation is altered in accordance with the present invention. Another feature of these changes is that 'because they are located below the damage-free, they have a wide range of viewing angles. - Marks made by prior art methods, tend to follow The change in viewing angle is particularly ambiguous in appearance, when the prior art nanosecond pulse is used to calibrate enough laser pulse energy to the surface to make a dark mark pair damage, which causes the appearance of the mark to vary with viewing angle. The characteristics of the mark made, no matter how deep the mark color, are not zoned, and will not be marked by the difference in the angle of view with the following laser parameters:

Table 1 'Laser parameters for color and grayscale markings Marks 60, 62, the imperceptible almost 6:6: The optical density range is optically dense relative to the unmarked grayscale 纟 all black #66. Between these two extremes (4) (4) is generated by moving the focal spot closer to the item 17 201208897 by increasing the energy density to create a darker mark. The change in height of the focal spot above the surface of the aluminum starts from zero, i.e., the darkest optical density mark 62, which is incremented by 5 〇〇 micron increments from right to left for each mark 64, 66 in Fig. 5, ending The lightest color mark at 5 mm above the surface 6〇^ Note that the mark 64 produced by the focal spot of 4.5 to 15 mm above the surface of the aluminum shows a brown or golden yellow color with a focal spot of one millimeter or less. The marks 62 and 66 produced by the person appear gray or black. Maintaining this precise control of the distance from the laser focal spot to the working surface and maintaining other laser parameters within the tolerances of normal laser processing, allowing it to be made of a predetermined color and optical density on the anodized aluminum. Laser marker. In addition, the darkest mark shows a CIE chromaticity less than L* = 40, a* = 5, and b* = l 0, 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 other than the gray scale can be produced on the anodized aluminum 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 oxide coatings. Careful selection of the laser pulse parameters will produce a predetermined golden color without damaging the oxide coating. Figure 5 also shows the various colors of golden or tan produced by one of the features of the present invention. The laser marking of the anodized aluminum can also be achieved by the use of IR waves + laser pulses to mark the aluminum. This feature produces markers of different gray scale densities by varying the laser energy density at the surface of the aluminum in two different ways. As described above, the gray scale can be created by changing the energy density at the surface by placing the focal spot 18 201208897 above or below the surface of the mark. One mode of controlling the gray scale is to change the total distance of the irradiation spot distance (bite 丨, v ) to change the total dose at the surface of the aluminum by marking the predetermined pattern. Changing the illumination point distance means adjusting the rate at which the laser pulse beam moves relative to the (4) surface or changing the pulse repetition rate or both of which results in a change in the distance between the aluminum-L continuous laser off-shoot and the impact position. Changing the line spacing means adjusting the distance between the marked lines to achieve a different degree of overlap. Figure 6 shows an aluminum article 74 having an array of -tags 72. These specifications have been arranged in an array of six rows and four columns. These six rows represent the z-direction height of the six focal spots above the surface of the aluminum range from 〇 (top column) to 5 mm (bottom column). The four columns represent the distance between 5, 1〇, 2〇 and 5〇 microns from left to right. It should be seen from Figure 6 that changing the z-direction height of the focal spot and changing the distance between the laser pulses can be produced in a predictable manner from less than

·:) and any reservation between D and almost transparent

CIE L learns the gray scale of density, which produces a mark on the anodized aluminum that meets the requirements of the business. Laser type DPSS Nd: YV04 Wavelength 1064 nm Pulse duration 10 picosecond pulse timing _ Gaussian laser power 2.5 W Repeat rate 500 KHz Speed 5 〇 mm / sec pitch 5, 10, 20, 50 μm spot size 55-130 Micron spot shape to s 201208897

Table 2: Laser pulse parameters for gray scale IR markers can be applied to the anodized aluminum by a picosecond or nanosecond laser pulse. The second type of label is used by the dyed anodization zone. The change in color contrast caused by discoloration. In general, 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 anodized aluminum after dyeing can, depending on the wavelength and the pulse energy, remove the dye when marking aluminum, so that the anodization zone becomes transparent, thereby revealing the mark on the underlying aluminum. come out. With a higher energy density, it is possible to perform both dye removal and the aluminum under the anodized layer marked with black, gray scale, or color as previously described. The lower energy pulse partially removes the dye from 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 marking that meets commercial requirements without causing discoloration of the anodized region. Figure 7 shows the dyed anodized aluminum article with a mark made from visible (532 nm) laser pulses. Note that the dye in the anodization zone is removed in the region where the pulse is received. Item 8 shows the same dyed anodized aluminum article with a mark made from IR (1〇64 nm) laser pulses. Note that the anodic oxygen zone is not decolored 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 an anodized tip using an anodized zone colored by a picosecond or nanosecond laser. Since % pole oxidation generally forms a porous surface, it is possible to introduce a dye which changes the appearance of aluminum. These dyes may be opaque or translucent, allowing a different amount of incident light to reach the aluminum' and being reflected back through the anodization zone. Figure 7 shows an anodized aluminum article 8 which, in accordance with one feature of the invention, has a pink tint in the anodization zone and is formed into an array of indicia 82. The color is produced by removing the dye from the oxide layer, and the underlying color shows the color from the original (silver) color to a series of laser-marked colors from brown to gray and finally to black. These colors are produced by varying the energy density of the laser pulses at the surface. The four columns in the figure change the distance between the laser pulses from 10 microns to 5 microns, while the line represents the change in the focal spot distance from the surface from 〇·〇 mm to 5.0 mm. These laser parameters in all cases result in the removal of the dye in the oxide covering the aluminum and allow the marking on the display 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 picoseconds rushing timing Gaussian laser power - 4W 虿 竿 500 KHz Speed 5 〇 mm / sec pitch 10 micron spot size 10-400 micron spot shape Gauss 21 201208897 Focus is still ϊ): 5 mm' -- Table 3: Laser parameters for visible oxide decolorization. % Polar oxidation zone dye removal is frequency dependent. As shown in Figure 7, the 532 nm laser pulse removes the dyeing of the anodization zone even when the lowest energy density is applied. On the other hand, the IR laser wavelength establishes a mark on the anodized aluminum after dyeing and does not remove the dye for most translucent dye colors. Figure 8 shows an anodized aluminum article 100 with a pink coloration and a mark 102 made with IR laser pulses. The marks are made from translucent to black and are made by modifying the laser energy density by changing the distance from the focal spot to the surface and by changing the pitch. The six rows in the figure represent 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 pitch from 丨〇 microns to 5 μm. The laser parameters used to generate these indications are shown in Table 4. Laser type DPSS Nd: Y〇V4 Wavelength 1064 nm Pulse duration 10 picosecond buffer timing Gaussian laser power 4W repetition rate 500 KHz Speed 50 mm / sec pitch 10 micron spot size 10-400 micron spot shape Gaussian focus height 0-5 mm _ Table 4: Laser parameters for IR colored anodized zone markings 201208897 Dyeing removal, labeling of aluminum and surface ablation of anodic oxidation zones for 532 nm (green) laser wavelengths The relationship between them is shown in Figure 9. For the 532 nm (green) laser pulse with the parameters given in Tables 1, 2 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. For the features of the present invention, the 532 nm laser pulse produces values of Fb = 〇1 Joules/cm 2 , Fu = 0.13 Joules/cm 2 , and & = 〇 18 Joules/cm 2 . Figure 1 shows the energy density threshold in joules per square centimeter for the 1 〇 64 nm (ir) laser pulse given the parameters given in Tables U and 3. In one feature of the invention, the energy density threshold of Joule/square centimeter for a 1064 nm (IR) laser pulse is Fu = 0.2 Joules / cm ^ 2 and Fs = 1 · 〇 Joule 7 cm ^ 2 . 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 and Fs will depend on the particular laser and optical module used. For a particular processing configuration and the item to be marked, it should be determined experimentally and stored in the controller for subsequent use. In another embodiment of the invention, the programmable nature of the conditioned laser processing system allows the anodized aluminum article to be marked to conform to commercially desirable marking patterns. As shown in Figure u, in this feature, a pattern 110 is converted into a digital representation 112 that is broken down into a list 23 201208897 114, where each item 丨i 6 in list ii 4 contains - location The representation of the 戋 complex position has a color A optical density associated with each location. List 1 14 is stored in controller 20. The controller 2 will each of the items 116 in the laser parameter concatenation list 114, when the laser parameters are transmitted as commands to the laser, the optical module 14, and the mobile control platform 22, The laser emits one or more laser pulses 12 that impinge on or near the surface 16 of the aluminum article 18. 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 the predetermined pattern on the anodized aluminum. Above the surface. In another embodiment of the invention, the colored anodization region is patterned over the previously patterned indicia to present additional color and optical density. X is in this feature, and the grayscale pattern is established in a pass. Above the anodized aluminum. The article is then coated with a photoresist coating that can be developed by exposure to a laser pulse. The gray-scale patterned and photoresist-coated articles are placed into the laser processing system and aligned to allow the servo system to accurately apply laser pulses to the pattern that has been applied to the article. The photoresist used is referred to as a "negative" photoresist, where the area of exposure = laser radiation will be removed, while the unexposed areas will retain the object. η continues the subsequent processing. The residual photoresist protects the surface of the article from being exposed to wood color and the exposed anodized region will be dyed with a predetermined color. This anodized layer is designed to be translucent to allow light to pass through the anode. The oxidized zone reaches the underlying pattern and is reflected back through the cation 24 201208897 polar oxidation zone to produce a colored pattern with selected electrical, color and optical densities. If the colored anodized zone is needed, it can also be utilized. The technique disclosed by the other features of the present invention decolorizes a predetermined color having a predetermined transparency. The color can be applied to the entire area of the lower pattern, or in a point-by-point manner, limited only by the laser. The resolution of the line system is usually in the range of 1 〇 to 400 μm. This action was initially repeated to produce multiple colors overlapping in one of the features of the present invention, which is multiple Applying an anodized color overlay in the form of a color overlay grid, such as a Bayer pattern. By designing the grayscale pattern to match the color overlay grid, a durable, commercial-compliant full color can be achieved. The image is created on an anodized top quality article. Figures 12a through 12i show a series of steps for creating such a color ink overlay using = color. In Figure 12a, the aluminum article i 18 has a transparent anodization. Layer 120 and indicia 122 previously applied in accordance with other features of the present invention. Negative photoresist 124 is applied to the surface of transparent anodized layer 12A. In Figure 12b, laser pulse 126 is directed to region 128 of photoresist 124, The exposure is performed at 13 Å. In Fig. 12c, the unexposed photoresist 134 remains after the photoresist treatment, but the exposed photoresist is removed, leaving the vacancies 132 in the processed photoresist layer 134. 12d shows that the anodized region in the portion 136 below the vacancy 132 of the photoresist layer 134 after the treatment is dyed in color in the base anodized layer. The photoresist layer after the intact treatment is prevented. Anodized zone The color, except for the region 132 of the treated photoresist layer 134 that has been removed. Figure I2e shows the base 118 of the article 118 containing the anodized region 136 having a color portion after removal of the treated photoresist layer. 201208897 The polar oxidation zone 120 and the relative position of the previously applied marker 12 2. Figure 12f shows that the article 118 has a base anodization region 120 comprising a color portion 136 and a second photoresist layer 138. Figure 12g shows the second stack of photoresist Layer 13 8 is illuminated by laser pulse 142 such that region 14 is exposed. Figure 12h shows article 11 with base anodization 120 for dyeing of the anodized region beneath removed photoresist 140 and removal of residual photoresist 138 After that. This causes the intact underlying anodized layer to contain the colored regions 136, 144' above the previously marked regions 122. Figure 12i shows that subsequent laser pulses 146 are used to selectively decolorize portions of the aluminum article that have previously been anodized and dyed to produce an additional predetermined color or optical density. The process described in this feature of the present invention causes the color image to be overlaid on the grayscale pattern' to produce a wide range of durable and commercially desirable color and optical density in a programmable pattern. In another embodiment of the invention, the colored anodized region can be formed on the anodized aluminum article using a particular pattern to produce the appearance of a full color image when viewed. Within this feature, a pattern representation of an image is applied to the surface using the techniques described herein. The color dyes are introduced in the manner illustrated in Figures 12a to 12i, but the pattern in which the dyes are introduced into the anodized base layer is designed to convert the gray scale representation into a full color. One example of this pattern is Bell. The filter (Bayer filter 'not shown') displays the red, green and blue filter elements in a pattern so that the eye's perception of red, green and blue elements blends into its optical density. The single-color associated with the grayscale mark below the colored anodization filter produces a full color image or the appearance of the pattern. 26 201208897 and exposing the pattern of the photoresist can be borrowed

The photoresist can be a negative or positive photoresist, produced by a mask, such as for direct writing by an electronic device, or by direct ablation by a laser.

圃" This example illustrates the anodized aluminum article by other means by which a low degree of damage is generated in the anodized layer but the anodized layer is not burned (iv). . Figure 13 shows an anodic oxygen treated article 〇5〇 having a white marking 152 created in such a manner in accordance with an embodiment of the present invention. This low level of damage involves a large number of small "micro" cracks in the anodization zone that illuminate all wavelengths of light, causing the surface to produce a "creamy" or cluster-like white appearance. Due to anodizing The area is not structurally damaged or broken in the size of the giant, so the surface maintains its durability and does not change significantly on the grain. The laser parameters used to create bright white markings on the anodized aluminum provide a slight a laser energy density greater than the damage threshold of the anodization zone. The laser b 1 is selected to be large enough to establish microcracks in the anodization zone, but not large enough to cause sufficient damage to change the article. Durability or appreciable texture. Table 5 contains the laser parameters used to create a bright white marking on an anodized aluminum article as shown in Figure 3. 27 201208897 Laser Type DPSS Nd: Y〇V4 wavelength 355 nm' pulse duration 100 nanosecond pulse timing ^ ; ~~ laser power 4W repetition rate 90 KHz speed 200 mm / sec pitch 10 micron ~ ~ Spot size 350-400 μm ~~~ Spot shape Shangs · Focus degree 0-5 mm~~~~' Table 5: Laser parameters for white anodized zone marking by approaching a specific anodization zone and The laser energy density used is changed within the specified range of the damage threshold of the article, and the appearance of the mark can vary from a light frosty surface to a completely opaque bright white color. In addition, this embodiment can oxidize this effect with coloring. The zones are combined to produce markers with different saturations. As the laser energy density increases, a dyed anodized layer will first appear unsaturated, meaning that the color appears to be blended into white. When the laser energy density increases, the coloring The anodization zone produces discoloration, while the markings exhibit a bright white appearance with no color.

The laser parameters used to generate the bright white markings include the use of a 5 m wavelength second resonant diode excited solid state Nd: γν〇4 laser, and the second system emits energy in the range of 266 to 532 nm. The high power pulse between the 'lasers. The s-Hai laser operates at 4 KW, and the base is in the range of i kw to (10) kW 28 201208897. The preferred embodiment is between 1 KW and 12 KW. The laser density ranges from approximately 〇 ! χ 1 〇 6 joules per square centimeter to (10) 焦 joules per square centimeter, or especially from 1.0 X ΙΟ 6 joules per square centimeter to 10·0 joules per square centimeter. The pulse duration ranges from 1 picosecond to 1 nanosecond (ns) or the preferred embodiment is from i nanosecond to nai laser repetition rate in the range from 丨KHz to 丨〇〇MHz. The application, or the preferred method of application, is from 〇KHz to i MHz. The speed at which the laser beam travels relative to the marked item ranges from i mm/sec to ιm, seconds, or the preferred embodiment is from i 〇〇 mm/sec to memi/sec. The surface of the article has a spacing or spacing between adjacent columns of laser pulses ranging from i microns to truncated microns, or a preferred embodiment is from 10 microns to 100 microns. The laser pulse spot size measured at the surface of the article ranges from 1 〇 micron to ι 微米 micron, or preferably from 5 〇 micron to 5 〇〇 micron. The location of the laser pulse focal spot relative to the surface of the item ranges from -ίο mm to +1 〇 mm, or especially from 0 to +5 mm. Figure 14 shows a clear anodized aluminum article 160 having a three-column mark 162 comprising six columns, each applied to the surface using a laser parameter of Table 5, wherein the spot size is from the leftmost row. : 〇0 μm increments from 60 μm per line to the rightmost line - the spacing or distance between adjacent lines of 500 μm 1 pulse, from the topmost / only to the middle column of 20 μm, to the most The bottom row is 5 microns. It can be seen that as the power increases, the brightness of the white mark increases and the transparency decreases. Embodiments of the present invention record an article with an infrared laser pulse containing a C〇2 laser. The white mark made by the change of the field in the anodized layer, successfully marks the laser ray used in the article of a nB t /x °, over % oxidized

The laser parameters used for marking the white anodization zone, the laser parameters used to establish such white markings include the use of a 10.6 micron wavelength CO 2 laser. The laser operates at 75 Kw' and is basically located in the range of 500 KW. The preferred embodiment is from 15 〇 kw. The f-radiation energy density ranges from approximately ι 〇X ι〇6 joules/square gong to 1 〇〇.〇 joules/cm 2 , or especially from 1.0 X 1 〇 6 joules per square a knife to 1 〇. 〇 joules / square centimeters. The duration of the pulse is in the range of from 1 to no continuous wave, or a preferred embodiment is from ^(10) nanoseconds to 100 milliseconds (ms). The laser repetition rate is in the range from 1 KHz to 1 MHz, or the preferred embodiment is from 丨〇KHz to 25 〇. The speed of the laser beam moving relative to the marked item ranges from 1 mm/sec to 10 The meter/second, or preferred embodiment, is from 1 mm/sec to ???m/30 201208897 seconds. The spacing or spacing between adjacent columns of laser pulses on the surface of the article is from 1 micron to 1000 microns, or preferably from 1 micron to 1 micron. The laser pulse spot size measured at the surface of the article ranges from 丨0 micrometers to 1000 micrometers, or preferably from 50 micrometers to 5 micrometers. The details of the foregoing embodiments may be varied without departing from the basic principles of the invention, and the scope of the invention should be apparent to those skilled in the art. [Simple diagram of the diagram] Figure 1, laser processing system. Figure 2 is a representation of the prior art nanosecond pulse system. Figure 3. Marks made in picosecond pulses. Figure 4, beam waist diameter. Figure 5' is a gray scale mark on anodized aluminum. Figure 6 'is located on the anodized mark. Figure 7. Aluminized anodized aluminum with a visible mark after dyeing. Figure 8 'Aluminized anodized aluminum with ir mark after dyeing. Figure 9' shows a plot of the threshold value of the visible laser pulse. Figure 10' shows a plot of IR laser pulse threshold values. Figure 11. Image data converted to laser parameters. Figures 12a-i are applied to the colored anodization zone of an aluminum article. Figure 13, white mark. Figure 14' is a gray scale mark on anodized aluminum. 31 201208897 [Explanation of main component symbols] 1 〇: Laser 12: Laser pulse 14: Laser optical module 16: Laser spot 1 8 : Item 20: Controller 22: Platform 3 0: Aluminized aluminum 32 : crack 34 : marked area 3 6 : anodized aluminum 3 8 : mark 40 : focal spot 42 : beam waist diameter surface 44 : optical axis 46 : diameter 48 : diameter 60-66 : mark 70 : anodized Aluminum 72: Mark 74: Aluminum Item 80: Aluminum Item 32 201208897 82: Mark I 00: Anodized Aluminum Item 102: Mark 110: Pattern 112: Digital Expression 114: List 116: Item II in the list 8: Aluminum article 120: transparent anodized layer 122: mark 124: photoresist layer 1 2 6 : laser pulse 128: photoresist region 1 3 0 : photoresist region 132: vacancy in the photoresist layer 1 3 4 : Photoresist layer 136: segment under the vacancy 1 3 8 : second photoresist layer 140 · region 142 in the second photoresist layer: laser pulse 144: colored region 146: colored region 1 5 0 : anodized Handled Item 152: White Mark 33 201208897 160 162 Fb : Fu .: Fs : : Anodized Aluminum Substance: Marking Energy Density Threshold for Decolorization in Anodized Zone Marking Energy Density Threshold for Aluminum under Anodic Oxidation Zone Energy Density Threshold for Surface Ablation 34

Claims (1)

201208897 VII. Patent Application Range: 1. A method for establishing a mark having a predetermined property on an anodized article, the predetermined property including optical density, color, texture, and longevity, the method comprising: providing a mine a marking system comprising a laser having a controllable laser energy density; determining the laser energy density associated with establishing the marking having a quantitative property; and directing the laser marking system to record the anodizing The treated sample has an anodized region that is substantially indistinguishable from the unmarked lines ranging from transparent to opaque. Using the determined laser energy density standard 'to establish the mark, the mark optical density, white color, and the texture of the week and durable and substantially complete. 2. As described in claim 1 of the patent scope. It is used to establish a method having a predetermined property σ - & on an anodized article, wherein the sample contains a metal. 3. The article has a predetermined genus containing aluminum as set forth in the second treatment of the patent application. The method for labeling an anodized f-producing substance, wherein the gold is used in an anodized article as set forth in claim 1 of the 4th S S ^ ^ # Predetermined method of hydrogen servant F妯-nine A^ §, wherein the cation is & is treated with permanent color plus laser. Set the standard with extra color A method for establishing a mark having a predetermined property on an article subjected to anodization 35 201208897 as described in the scope of the patent application, wherein the dyed anodized region is further decolored by a laser. 6. A mark made by laser on an anodized sample 'has an optical density ranging from transparent to opaque, a white color, a texture that is indistinguishable from surrounding unmarked lines, and durable and substantially intact. The appearance of the mark in the anodization zone '纟 is the result of laser induced damage that scatters light in the anodized layer. 7. A mark made by laser on an anodized sample as described in claim 6 of the scope of the patent, wherein the sample comprises a metal. 8. A mark made by laser on an anodized sample as described in claim 7 of the scope of the patent application, wherein the metal contains aluminum. 9. A mark made by laser on an anodized sample as described in claim 6 wherein the anodized region is dyed plus a laser treatment to create the mark having an additional color. 1A. A mark made by laser on an anodized sample as described in claim 9 of the patent application, wherein the dyed anode oxidized region is additionally decolored by a laser. Eight, the pattern: (such as the next page) 36