Optimizing Energy Delivery for Laser Thickness Control of Fusion Glass Systems and Methods

Abstract

Apparatus and methods for controlling glass thickness during the production of glass sheets are described. The apparatus and methods use a laser beam to heat specific portions of molten glass. In some examples, a laser beam control system controls the laser beam to produce a more consistent glass thickness across the glass sheet. In some examples, the laser beam control system multiplexes the laser beam to heat different portions of the glass, for example, simultaneously.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62 / 924,312, filed October 22, 2019, which is relied upon and incorporated by reference in its entirety into this application. [Technical field]

[0002] FIELD OF THE DISCLOSURE This disclosure relates to the production of glass sheets, and more particularly to an apparatus and method for controlling glass thickness during the production of glass sheets. [Background technology]

[0003] Glass sheets are used in a variety of applications. For example, glass sheets can be used in glass display panels, such as mobile devices, laptops, tablets, computer monitors, and television displays. Glass sheets can be produced by a fusion downdraw process, in which molten glass is drawn on a glass forming device. For a variety of applications, precise control of the thickness of the produced glass can be important. When a glass ribbon is being formed by a fusion downdraw process, the thermomechanical and glass flow conditions can be non-uniform across the entire or a portion of the width of the glass ribbon. For example, the surface tension of the glass ribbon when it is being formed can be insufficient to completely avoid variations that may occur in the thickness of the glass ribbon. In some instances, the variations in glass thickness can be in the order of a few micrometers, but such variations are undesirable because the consequences can be significant. Thus, there is an opportunity for improvement in the production of glass sheets. Summary of the Invention

[0004] The features disclosed herein allow for control of glass (e.g., ribbon) thickness in a glass forming apparatus using energy delivered by a laser. For example, the features disclosed herein can improve the uniformity, precision, speed, and control of the laser energy delivered by the laser to produce relatively more uniform glass. Among other advantages, embodiments can allow for consistent laser energy delivery along a sheet of molten glass. The embodiments can also allow for automatic compensation for beam position deviations and power losses as the laser scans the window. In some examples, the embodiments can allow for mitigation of down-the-draw variability relative to the draw direction, for example, by providing modifications to the laser beam shape. Some embodiments can also employ multiple laser beams to heat the molten glass, which can allow for more rapid scanning of the molten glass. These embodiments can also allow for a larger area of ​​the molten glass to be scanned using a single scanning system. Those skilled in the art having the benefit of this disclosure can recognize other benefits as well. [Means for solving the problem]

[0005] In some examples, a laser control system can preselect a portion of the molten glass in a glass forming apparatus. The laser control system can configure a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass. The laser control system can determine a power density for the laser beam based on an angle of incidence of the laser beam on the preselected portion of the molten glass. The laser control system can also operate the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass.

[0006] In some examples, the laser control system can determine the angle of incidence of the laser beam relative to the preselected portion of the molten glass based on a position of the reflector.

[0007] In some examples, the laser control system can determine an amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass based on the angle of incidence. The laser control system can then determine the power density for the laser beam based on the amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass.

[0008] In some examples, the laser control system can determine a lateral displacement that the laser beam will experience as it advances through at least one window and can then configure the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass based on the determined lateral displacement.

[0009] In some examples, the laser control system can determine the length the laser beam travels from the reflector to the preselected portion of the molten glass. The laser control system can then configure the laser generator to generate the laser beam with a waist located at the preselected portion of the molten glass. In some examples, the laser control system can deactivate the laser generator to disable the laser beam. The laser beam control system can then configure the reflector to reflect the laser beam from the laser generator to another preselected portion of the molten glass. The laser control system can also determine the length the laser beam travels from the reflector to the other preselected portion of the molten glass and configure the laser generator to generate the laser beam with a waist located at the other preselected portion of the molten glass. The laser control system can then reactivate the laser generator to enable the laser beam. In some examples, the laser control system maintains the laser generator enabled as the laser control system configures the reflector to reflect the laser beam to various portions of the molten glass. For example, the laser control system can modulate the laser power and change the laser power to a very low adjustment point (e.g., near zero power) when there is no need to provide thermal energy to the glass (e.g., a section that is already thin enough), and then the laser control system can increase the laser beam power as it covers the section of glass that is desired to be thinned.

[0010] In some examples, the laser control system can use a beam shaping element, such as a diffractive optical element (DOE) or a spatial light modulator (SLM), that modulates (e.g., shapes) the incident laser beam so that the laser beam pattern projected onto the molten glass has a predetermined energy distribution. The laser control system can adjust the spatial distribution of the energy delivered by the laser to meet application needs (e.g., uniform energy throughout the molten glass taking into account contours, etc.).

[0011] In some examples, the apparatus includes a laser generator operable to generate a laser beam. The apparatus can also include a reflector configured to reflect the laser beam from the laser generator to the molten glass of a glass forming apparatus. The apparatus can also include a controller communicatively coupled to the laser generator and the reflector. The controller can be configured to preselect a portion of the molten glass of the glass forming apparatus. The controller can also be configured to configure the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass. The controller can be configured to determine a power density for the laser beam based on an angle of incidence of the laser beam to the preselected portion of the molten glass. The controller can also be configured to operate the laser generator to generate the laser beam of the determined power density to heat the preselected portion of the molten glass.

[0012] In an embodiment, the disclosure describes an apparatus comprising: a memory device storing instructions; and a controller comprising at least one processor and configured to execute the instructions, which, when executed, cause the controller to: preselect a portion of molten glass in a glass forming apparatus; configure a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determine a power density for the laser beam based on an angle of incidence of the laser beam with respect to the preselected portion of the molten glass; and operate the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass.

[0013] In another embodiment, the disclosure describes an apparatus comprising: a laser generator operable to generate a laser beam; a reflecting device configured to reflect the laser beam from the laser generator to a glass forming apparatus; and a controller communicatively coupled to the laser generator and the reflecting device. The controller may be configured to: preselect a portion of molten glass at the glass forming apparatus; configure the reflecting device to reflect a laser beam from the laser generator to the preselected portion of the molten glass; determine a power density for the laser beam based on an angle of incidence of the laser beam to the preselected portion of the molten glass; and operate the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass.

[0014] In yet another embodiment, the present disclosure describes a method for heating molten glass in a glass forming apparatus, the method including: preselecting a portion of molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam to the preselected portion of the molten glass; and operating the laser generator to generate the laser beam at the determined power density, thereby heating the preselected portion of the molten glass.

[0015] In a further embodiment, the present disclosure describes a method for heating molten glass in a glass forming apparatus, the method including: preselecting a portion of molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator to the preselected portion of the molten glass; determining a length that the laser beam travels from the reflector to the preselected portion of the molten glass; and configuring the laser generator to generate the laser beam having a waist positioned at the preselected portion of the molten glass.

[0016] In still a further embodiment, the present disclosure describes a method for heating molten glass in a glass forming apparatus, the method including: preselecting a portion of molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator to the preselected portion of the molten glass; determining a length that the laser beam travels from the reflector to the preselected portion of the molten glass; configuring the laser generator to generate the laser beam having a waist positioned at the preselected portion of the molten glass; and operating the laser generator to generate the laser beam.

[0017] In a further embodiment, the present disclosure describes a method for heating molten glass in a glass forming apparatus, the method including: determining a position of a reflector relative to molten glass to be heated by a laser beam; determining an expected angle of incidence of the laser beam reflecting from the reflector onto the molten glass; calculating a power density for the laser beam based on the calculated angle of incidence; and configuring a laser generator to generate the laser beam having the calculated power density.

[0018] In some examples, a multiplexed laser control system includes: a laser generator for generating a laser beam; a dynamic focus device; a multiplexer; and a plurality of beam scanning devices. The laser generator is configured to generate a laser beam and deliver the laser beam through the dynamic focus device. The dynamic focus device applies at least one dynamic focusing operation to the laser beam and directs the focused laser beam to the multiplexer. The multiplexer delivers the laser beam to the plurality of beam scanning devices sequentially (e.g., on a time basis) or simultaneously. Each of the beam scanning devices may deliver the laser beam to a portion of the molten glass in a glass forming apparatus.

[0019] In another embodiment, the present disclosure describes a method for heating molten glass in a glass forming apparatus, the method including: configuring a multiplexer to supply a laser beam to a plurality of beam scanning devices; synchronizing a dynamic focus device to the plurality of beam scanning devices; configuring a laser beam generator to generate the laser beam, the laser beam proceeding from the laser generator to the multiplexer and from the multiplexer to the plurality of beam scanning devices; and heating a portion of the molten glass using the laser beam from at least one of the plurality of beam scanning devices.

[0020] The above summary and the following detailed description of exemplary embodiments may be read in conjunction with the accompanying drawings, which illustrate some of the exemplary embodiments described herein. As further explained below, the claims are not limited to these exemplary embodiments. For clarity and readability, the drawings may omit the illustration of certain features. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of an exemplary glass forming apparatus with a laser beam control system, according to some examples. [Diagram 2] 1 is a block diagram of an exemplary laser beam control system, in accordance with some examples; [Figure 3A] 2 is a diagram illustrating a laser beam generated by the glass forming apparatus of FIG. 1 incident on a portion of glass, according to some examples. [Figure 3B] 2 is a diagram illustrating a laser beam generated by the glass forming apparatus of FIG. 1 incident on a portion of glass, according to some examples. [Figure 4] 2 shows the intensity of reflected laser light from a laser beam generated by the glass forming apparatus of FIG. 1 at various angles of incidence, according to some examples. [Diagram 5] Lateral displacement experienced by a laser beam advancing through a window, according to some examples. [Figure 6A] Shaping a laser beam with the laser beam control system of FIG. 2, according to some examples. [Figure 6B] Shaping a laser beam with the laser beam control system of FIG. 2, according to some examples. [Figure 7A] Stretching a laser beam by the laser beam control system of FIG. 2, according to some examples. [Figure 7B] Stretching a laser beam by the laser beam control system of FIG. 2, according to some examples. [Figure 8] Positioning the waist of a laser beam on glass with the laser beam control system of FIG. 2, with some examples [Figure 9A]The length the laser beam travels at an angle before reaching the glass, in some examples. [Figure 9B] The length the laser beam travels at different angles before reaching the glass, in some examples. [Figure 10A] A chart showing the length a laser beam travels at an angle before reaching glass, with some examples. [Figure 10B] A chart showing the length a laser beam travels at various angles before reaching glass, with some examples. [Figure 11] 1 is a schematic diagram of an exemplary multiplexed laser beam control system, in accordance with some examples; [Figure 12] 1 is a schematic diagram of an exemplary multiplexed laser beam control system, in accordance with some examples; [Figure 13] 1 is a schematic diagram of an exemplary multiplexed laser beam control system, in accordance with some examples; [Figure 14] 1 is a schematic diagram of an exemplary multiplexed laser beam control system, in accordance with some examples; [Figure 15] 1 is a schematic diagram of an exemplary multiplexed laser beam control system, in accordance with some examples; [Figure 16] Exemplary methods that may be performed by a laser beam control system, according to some examples [Figure 17] Another exemplary method that may be performed by a laser beam control system, according to some examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] This application discloses exemplary embodiments. This disclosure is not limited to these exemplary embodiments. Thus, many implementations of the claims will differ from these exemplary embodiments. Various modifications can be made to the claims without departing from the spirit and scope of this disclosure. The claims are intended to cover implementations with such modifications.

[0023] This application often uses directional terms (e.g., "front," "back," "top," "bottom," "right," "left," etc.) to give the reader a context for viewing the drawings. The claims, however, are not limited to the orientation shown in the drawings. Any absolute term (e.g., "high," "low," etc.) shall be understood to disclose the corresponding relative term (e.g., "higher," "lower," etc.).

[0024] The present disclosure presents an apparatus and method for controlling ribbon thickness using energy delivered by a laser during a glass forming process, in some examples improving the uniformity, precision, speed, and / or control of the laser energy delivered by the laser to the glass ribbon.

[0025] Among other advantages, embodiments can enable consistent laser energy delivery along the sheet of molten glass. Embodiments can also enable automatic compensation for beam position deviations and power losses as the laser scans the window. In some examples, embodiments can enable mitigation of directional variations downward relative to the draw direction, for example by providing modifications to the laser beam shape. Some embodiments can also employ multiple laser beams to heat the molten glass, which can enable more rapid scanning of the molten glass. These embodiments can also enable a larger area of ​​the molten glass to be scanned using a single scanning system. Those skilled in the art having the benefit of this disclosure can recognize other advantages as well.

[0026] In some examples, the laser beam is directed toward the molten glass ribbon, e.g., above the root level, by a laser beam control system that induces a decrease in viscosity, possibly creating a new surface tension equilibrium in the molten glass ribbon, and that manifests in the cooled glass, e.g., as a decrease in glass thickness.

[0027] The laser beam control system can, in some instances, compensate for glass thickness changes caused by a decrease in viscosity, which potentially creates a new surface tension equilibrium in the molten glass ribbon and is manifested in the cooled glass as, for example, a decrease in glass thickness.

[0028] In some examples, the laser beam control system compensates for errors (e.g., loss of laser beam energy) caused by the angle of incidence of the laser beam and reflections (e.g., Fresnel reflections) of the laser beam. In some examples, the laser beam control system compensates for transmission losses of the laser beam through portions such as windows (e.g., glass or plastic windows) of a glass forming system. The laser beam control system can enable application of a constant energy profile across the molten glass ribbon (e.g., glass sheet).

[0029] In some examples, the laser beam control system improves glass thickness consistency by modifying the beam shape of the laser beam directed at the molten glass during the glass forming process. In some examples, the laser beam control system improves glass thickness consistency by adjusting the placement of the laser beam waist based on the angle of the laser beam relative to the glass and the length from the laser beam source to the target area of ​​the molten glass ribbon.

[0030] In some examples, the laser beam control system scans the ribbon of molten glass with multiple laser beams: to scan the glass more quickly; to cover larger areas of glass with a single scanning system (i.e., for scalability); and / or to more easily create fixed (or time-varying) laser beam patterns on the glass. In some examples, the laser beam control system uses diffractive optics, acousto-optic modulators, or other optical and electronic means to split a single laser beam into multiple laser beams that are directed simultaneously or sequentially at the ribbon of molten glass.

[0031] Referring to FIG. 1, glass forming apparatus 20 includes a forming wedge 22 having an open channel 24 surrounded on its longitudinal sides by walls 25 and 26. The upward extent of walls 25 and 26 terminate in longitudinally extending, opposed overflow weirs 27 and 28, respectively. Overflow weirs 27 and 28 are integral with a pair of opposed, generally vertical forming surfaces 30, which in turn are integral with a pair of opposed, downwardly sloping, converging forming surfaces 32. The pair of downwardly sloping, converging forming surfaces 32 terminate at a generally horizontal lower apex that constitutes a base 34 of forming wedge 22. Each downwardly sloping, converging forming surface 32, in some instances, includes a pair of edge direction determiners 50. One downwardly sloping, converging forming surface 32 and a corresponding pair of edge direction determiners are shown in FIG. 1.

[0032] Molten glass is delivered into the open channel 24 by a delivery passage 38 in fluid communication with the open channel 24. A pair of dams 40 are provided adjacent each end of the open channel 24 and above the overflow weirs 27 and 28 to direct the overflow of the molten glass free surface 42 over the overflow weirs 27 and 28 as multiple separate streams of molten glass. Only the pair of dams 40 located at the end of the open channel 24 adjacent the delivery passage 38 is shown in FIG. 1. The multiple separate streams of molten glass flow over the pair of opposing generally vertical forming surfaces 30 and the opposing downwardly sloping converging forming surfaces 32 down to the base 34 where the multiple separate streams of molten glass converge to form a glass ribbon 44, as shown by the dashed lines in FIG. 1. Each pair of edge directors 50 maintains the molten glass along a respective downwardly sloping and converging forming surface 32 until the molten glass reaches base 34 .

[0033] The pulling rolls 46 are located downstream of the base 34 of the forming wedge 22 and engage opposite side edges 48 of the glass ribbon 44 to apply tension to the glass ribbon 44. By positioning the pulling rolls 46 sufficiently below the base 34, the thickness of the glass ribbon 44 can be substantially fixed at that position. The pulling rolls 46 can pull the glass ribbon 44 downward at a predetermined rate that establishes the thickness of the glass ribbon as it is formed at the base 34.

[0034] FIG. 1 also illustrates an exemplary laser beam control system 10, which may include a laser generator 12 configured to generate and emit a laser beam 13. In an embodiment, the laser beam 13 is directed to the molten glass below (e.g., directly below) the base 34, where the laser beam energy provided by the laser beam 13 is uniform at multiple points of incidence across the molten glass. As illustrated in the embodiment of FIG. 1, the laser beam 13 may be directed by the laser generator 12 to the molten glass, for example, via a reflector 14. Although one laser generator 12 is illustrated generating the laser beam 13 relative to the reflector 14, in some examples, additional laser beam control systems 10 may use additional laser generators 12 and / or reflectors 14. For example, the laser beam control system 10 may use a second laser generator 12 to direct the laser beam to the molten glass via the reflector 14. In another example, the laser beam control system 10 may use a second laser generator 12 to direct the laser beam to the molten glass via the reflector 14.

[0035] In certain embodiments, the reflector 14 can include a reflective surface 15 that is configured to receive and reflect the laser beam 13 generated and emitted by the laser generator 12 toward at least a predetermined portion of the molten glass. The reflector 14 can be, for example, a mirror configured to deflect the laser beam from the laser generator 12. Thus, the reflector 14 can function as a beam steering and / or scanning device. In FIG. 1, the laser beam 13 is illustrated as being advanced by the reflector 14 toward a plurality of preselected portions of the molten glass as reflected laser beams 17.

[0036] In some instances, the reflective surface 15 may comprise a gold coated mirror, although in other instances other types of mirrors may be used. Gold coated mirrors may be desirable in certain applications to provide a consistent reflectance, for example better than an infrared laser. Furthermore, the reflectance of a gold coated mirror is substantially independent of the angle of incidence of the laser beam 13, making gold coated mirrors particularly useful as mirrors for scanning or laser beam steering.

[0037] 1 may also include an adjustment mechanism 16 (e.g., a galvanometer or polygon scanner) configured to adjust the attitude of the reflective surface 15 of the reflecting device 14 relative to receipt of the laser beam 13 and the position of a preselected portion of the edge direction determiner 50. For example, the reflecting device 14 may rotate or tilt the reflective surface 15, for example, to direct the laser beam 13 to a predetermined portion of the edge direction determiner 50 as a reflected laser beam 17.

[0038] According to one example, adjustment mechanism 16 can include a galvanometer operatively associated with reflective surface 15 such that the galvanometer can rotate reflective surface 15 along an axis relative to glass ribbon 44. For example, reflective surface 15 can be mounted on a rotatable shaft 18 that is driven by a galvanometer motor to rotate about axis 18a, as indicated by double arrow 19.

[0039] 2 illustrates portions of an exemplary laser beam control system 10, where solid lines with arrows represent laser beams (e.g., laser beam 13, reflected laser beam 17) and dashed lines represent electrical control signals. In this example, the laser beam control system 10 can include a laser power control unit 55 and a control computer 52. The laser power control unit 55 and the control computer 52 can each include one or more processors, one or more field-programmable gate arrays (FPGAs), one or more application-specific integrated circuits (ASICs), one or more state machines, digital circuits, or any other suitable circuit configuration. In some embodiments, one or more of the laser power control unit 55 and the control computer 52 can be implemented as any suitable hardware, or hardware and software (e.g., one or more processors executing instructions stored in a memory). For example, a non-transitory computer-readable medium, such as, for example, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a removable disk, a CD-ROM, any non-volatile memory, or any other suitable memory, can store instructions that can be retrieved and executed by one or more processors of any of the laser output control unit 55 and the control computer 52 to perform one or more of the functions described herein.

[0040] The laser output control unit 55 can control the operation of the laser generator 12 such that the pulse energy, beam width, power level, and / or wavelength of the laser beam 13 generated by the laser generator 12 have predetermined values. Furthermore, the laser output control unit 55 can control the time interval during which the laser generator 12 generates the laser beam 13. The control computer 52 can then be provided to control the operation of the laser output control unit 55, which can cause the laser generator 12 to generate the laser beam 13 having preselected wavelengths and power characteristics during preselected time intervals. At the same time, the control computer 52 can be operatively associated with the reflecting device 14, which can control the function of the adjustment mechanism 16 and, in the particular example employing a galvanometer, the motor of the galvanometer. The control computer 52 can thus adjust the attitude and positioning of the reflecting surface 15 relative to the reception of the laser beam 13 by the reflecting surface 15, as well as the position of the preselected portion of the molten glass.

[0041] For example, control computer 52 can configure adjustment mechanism 16 to adjust (e.g., tilt or rotate) reflective surface 15 of reflecting device 14 to a number of different orientations for receiving and reflecting laser beam 13 at reflective surface 15 of reflecting device 14 during a preselected time period, such that laser beam 13 can be directed to a number of preselected portions of the molten glass during each preselected time period, thereby controlling the thickness of the molten glass, as shown by reflected laser beam 17 in FIG.

[0042] In some examples, as described further below, the laser beam control system 10 may include a dynamic focus module that directs the laser beam to a multiplexer. The multiplexer may be, for example, a time multiplexer or a division multiplexer. The multiplexer may direct the laser beam to one or more beam splitters. The beam splitters may split the laser beam into multiple laser beams that may be directed to the molten glass. In some examples, the laser beam control system 10 may include additional reflective surfaces 15 and / or corresponding adjustment mechanisms 16 to direct the laser beam to the molten glass. In some examples, the controlling computer 52 may configure one or more of the multiplexers, beam splitters, and adjustment mechanisms.

[0043] 3A and 3B show a laser beam 302, such as that generated by laser beam control system 10, incident on a portion of the molten glass such that the laser beam forms laser beam shape 304 on the molten glass. The molten glass is positioned at the location of the opposing arrows in FIGS. 3A and 3B. In FIG. 3A, the angle of incidence of laser beam 302 on the portion of the molten glass is 0° (i.e., perpendicular to the portion of the molten glass). In FIG. 3B, the angle of incidence of laser beam 302 on the portion of the molten glass is greater than 0° (i.e., oblique to the portion of the molten glass), causing laser beam 302 to form laser beam shape 306 on the molten glass. As shown by laser beam shape 304 in FIG. 3A and laser beam shape 306 in FIG. 3B, the power density of laser beam 302 across the portion of the molten glass is lower in FIG. 3B compared to FIG. 3A due to the increased angle of incidence. Thus, as the incidence angle of laser beam 302 increases, the power density of laser beam 302 across the portion of the molten glass decreases, resulting in a non-uniform distribution of the laser energy density across the molten glass.

[0044] In some examples, the laser beam control system 10 compensates for the decrease in laser energy density with the angle of incidence of the laser beam 302 on the molten glass. For example, the control computer 52 can configure the adjustment mechanism 16 to adjust (e.g., tilt or rotate) the reflective surface 15 of the reflector 14 to direct the laser beam 302 at a certain angle of incidence to the molten glass. Based on the adjustment to the reflective surface 15, the control computer 52 can calculate the expected power density of the laser beam 302 based on the angle of incidence of the laser beam 302. For example, when the reflective surface 15 directs the laser beam 302 away from the center of the molten glass (assuming the reflective surface is in line with the center of the molten glass as shown in FIG. 1), the control computer 52 can cause the laser power control unit 55 to increase the power of the generated laser beam 302. Thus, the laser beam control system 10 maintains the same power density as the laser beam scans the molten glass.

[0045] FIG. 4 shows a chart illustrating the intensity of a reflected laser beam incident on molten glass. As shown, the intensity of the reflected laser beam tends to increase at angles of incidence exceeding Brewster's angle. The intensity also varies based on the polarization of the laser beam, as shown by the various curves. In this example, curve Rp identifies the intensity for the reflection of a P-polarized laser beam from the molten glass, and curve Rs identifies the intensity for the reflection of an S-polarized laser beam from the molten glass.

[0046] In some examples, the laser beam control system 10 compensates for increased laser energy reflection with the angle of incidence of the laser beam 302 on the molten glass. For example, the control computer 52 can configure the adjustment mechanism 16 to adjust (e.g., tilt or rotate) the reflective surface 15 of the reflector 14 to direct the laser beam 302 at a certain angle of incidence to the molten glass. Based on the adjustment to the reflective surface 15, the control computer 52 can calculate the expected power density of the laser beam 302 based on the angle of incidence of the laser beam 302. For example, when the reflective surface 15 is directing the laser beam 302 away from the center of the molten glass (assuming the reflective surface is in line with the center of the molten glass as shown in FIG. 1), the control computer 52 can cause the laser power control unit 55 to increase the power of the generated laser beam 302. Thus, the laser beam control system 10 maintains the same power density as the laser beam scans the molten glass.

[0047] FIG. 5 illustrates the lateral displacement, represented by "d", experienced by a laser beam 502 advancing through a window 504. This displacement is caused by a principle of physics related to Snell's Law and, at least in some examples, can be calculated according to the equation shown in the figure. In this equation, "n2" represents the refractive index relative to the material of the window 504 and "n1" represents the refractive index relative to the environment outside the window, e.g., air. In some examples, a window laminate is used or a water cooling layer is used between the windows. In these examples, the above equation is modified depending on the optical stack of the window.

[0048] In some examples, the laser beam control system 10 compensates for lateral displacements that occur to the laser beam 502 as it advances through a window, such as the window 504. For example, the control computer 52 can calculate the expected lateral displacement of the laser beam 502 as it advances through a window, for example, based on Snell's law (e.g., the equation shown in FIG. 5). The control computer 52 can configure the adjustment mechanism 16 to adjust (e.g., tilt or rotate) the reflecting surface 15 of the reflecting device 14 based on the expected lateral displacement caused by the window to direct the laser beam 502 toward the molten glass. For example, assume that the laser beam 502 advances through a window before reaching the target portion of the molten glass. Also assume that the control computer 52 calculates the expected lateral displacement of the laser beam as it advances through the window at an angle greater than 0° (e.g., not perpendicular to the window). The control computer 52 can configure the adjustment mechanism 16 to adjust the reflective surface 15 of the reflector 14 so that the laser beam 502, when reflected from the reflector 14, is incident on the window at a location that is offset by the amount of the expected lateral displacement. Thus, the laser beam 502 can reach the target location in the molten glass after advancing through the window (e.g., rather than offset by the amount of the calculated lateral displacement).

[0049] 6A and 6B show shaping of a laser beam by the laser beam control system 10. FIG. 6A shows a laser beam 602 having a laser beam profile 604. The laser beam control system 10 can shape the laser beam as shown in FIG. 6B, for example, using one or more beam shaping elements. Each beam shaping element can be, for example, a diffractive optical element (DOE) or a spatial light modulator (SLM). In some examples, one or more of a slit, a pinhole, a lens, and / or a mirror are used to shape the laser beam.

[0050] For example, as shown in FIG. 6B, the laser beam 608 can be shaped by one or more beam shaping elements. As shown, the laser beam 608 has sharper edges than the laser beam 602. For example, compared to the laser beam 602, the laser beam 608 is shaped to a shape more similar to a "top hat". As a result of generating the laser beam 608, the thickness features of the heated glass can have more clearly defined (e.g., sharper) edges. Thus, the effect from the laser beam 608 on the glass can be more narrowly localized, resulting in higher spatial frequency thickness features. FIG. 8 also shows a laser beam profile 610 for the laser beam 608. When the laser beam 608 impinges on the molten glass, a heat affected zone can be created on the molten glass. The heat affected zone created by the laser beam 608 can be more narrowly defined than the heat affected zone created by the laser beam 602. Thus, by generating the laser beam 608, the laser beam control system 10 can more precisely control where to create heat on the molten glass. For example, the laser beam control system 10 can create sharper edges in the top hat beam, thus providing more precise control over where to direct the heat on the glass, and can provide more uniform heating along the beam profile compared to a traditional Gaussian beam.

[0051] In some examples, the laser beam control system 10 can stretch the laser beam, for example, using one or more beam shaping elements. For example, FIG. 7A shows a laser beam having a nominal (e.g., small, symmetric) beam shape that can allow for gaps in the scan (e.g., areas of the molten glass that are not "hit" by the laser beam) when scanning the molten glass at a constant height. In this example, gaps exist in the scan pattern as a result of the glass moving perpendicular to the back-and-forth scanning motion from the scanner. However, FIG. 7B shows a laser beam stretched by the laser beam control system 10 (e.g., with one or more beam shaping elements). In this example, by stretching the laser beam, the laser beam control system 10 reduces or eliminates gaps in the scan of the molten glass (e.g., as the molten glass moves perpendicular to the back-and-forth scanning motion from the scanner). In some examples, the laser beam control system 10 stretches the laser beam in the draw direction to minimize or eliminate gaps in the application of the laser beam to the molten glass. In some examples, the laser beam control system 10 elongates the laser beam in the scan direction to minimize or eliminate gaps in the application of the laser beam to the molten glass.

[0052] 8 illustrates the positioning of a laser beam waist of laser beam 802 on molten glass 804 by laser beam control system 10. For example, as laser beam 802 scans molten glass 804, the distance "L" from laser beam source 810 (e.g., reflector 14) to molten glass 804 changes, but the laser beam waist 806 of laser beam 802 remains at a distance "R" to laser beam source 810. For example, as shown, the laser beam waist 806 (represented by opposing arcs) of laser beam 802 at normal incidence (e.g., θ=0°) on molten glass 804 may occur behind molten glass 804. Similarly, the laser beam waist 806 of an otherwise identical laser beam 802 incident at a non-zero angle (e.g., θ>0°) may occur in front of molten glass 804.

[0053] In some examples, such as when fixed optics are used to deliver laser beam 802 from laser generator 12 through laser beam source 810 to molten glass 804, controlling computer 52 causes laser power control unit 55 to generate laser beam 802 such that the waist of laser beam 802 occurs at the same distance from laser beam source 810 regardless of the angle of incidence of laser beam 802 on the molten glass (e.g., as shown in FIG. 8 ). In this example, controlling computer 52 configures laser power control unit 55 to generate laser beam 802 such that the waist of laser beam 802 occurs at a distance (e.g., “h”) behind molten glass 804 when laser beam 802 is incident on molten glass 804 at a normal angle (e.g., θ=0°). This distance can be the same distance that the waist of laser beam 802 is in front of the molten glass when laser beam 802 is incident on the molten glass 804 at a maximum angle (e.g., θ is such that laser beam 802 is intercepted at the edge of molten glass 804).

[0054] FIG. 9A shows the additional distance (denoted as "ΔL") that laser beam 802 travels from laser beam source 810 to molten glass 804 when the laser beam is at an angle θ from normal to molten glass 804. In other words, FIG. 9A shows an approach where laser beam 802 is scanned symmetrically ±θ with respect to the angle normal to the glass, where laser beam 802 is nominally pointed straight at the glass. FIG. 10A shows a chart with a curve showing the percentage of the additional distance laser beam 802 needs to travel relative to the original distance (denoted as "L"). FIG. 9B shows another additional distance (denoted as "ΔL'") that laser beam 802 travels from laser beam source 810 to molten glass 804. In this example, laser beam 802 is nominally tilted at angle φ with respect to the glass. Additionally, molten glass 804 is scanned symmetrically ±θ with laser beam 802. FIG. 10B shows a chart with various curves that indicate the additional distance that the laser beam 802 needs to travel as a percentage of the original distance, where each curve represents an initial angular displacement θ.

[0055] In some examples, the laser beam control system 10 compensates for the changing location of the laser beam waist. For example, the control computer 52 can configure the adjustment mechanism 16 to adjust (e.g., tilt or rotate) the reflective surface 15 of the reflector 14 to direct the laser beam 302 at an angle of incidence toward the molten glass. The control computer 52 can calculate (e.g., based on a known distance from the reflective surface 15 to the molten glass 804 and the angle of incidence of the laser beam relative to the molten glass 804) the distance (e.g., distance "L") that the laser beam 802 travels. In some examples, the laser beam control system 10 can control where the waist of the laser beam 802 occurs. For example, the laser beam control system 10 can optically control where the waist of the laser beam 802 occurs by adding optical elements between the laser generator 12 and the reflector 14 or by using an adjustable optical module such as a dynamic focus device 1102 (described further below). For example, when reflective surface 15 is directing laser beam 802 away from the center of molten glass 804 (assuming the reflective surface is aligned with the center of molten glass, as shown in FIG. 1 ), controlling computer 52 may cause laser power control unit 55 to generate laser beam 802 such that the waist of laser beam 802 occurs at a greater distance from reflective surface 15 (e.g., as compared to when laser beam 802 is directed at the center of molten glass 804). Thus, laser beam control system 10 maintains the occurrence of the waist of laser beam 802 at or near molten glass 804 as laser beam 802 scans molten glass 804. In some examples, controlling computer 52 controls a dynamic focus device (described further below) to compensate for changes in the distance from laser beam source 810 to molten glass 804 such that the waist of laser beam 802 is positioned along molten glass 804 throughout the scan.

[0056] FIG. 11 illustrates a multiplexed laser beam control system 1100, which includes: a laser generator 12 (which may include a laser power control unit 55 in some examples); a dynamic focus device 1102; a multiplexer 1104 (e.g., a laser beam multiplexing device); and a plurality of beam scanning devices 1106 for directing the laser beam 1101 from the laser generator 12 to the molten glass 1150. In this example, the glass is nominally flowing in a direction perpendicular to the plane of the laser scan (i.e., into / out of the page). The molten glass 1150 may be provided, for example, by the glass forming apparatus 20 of FIG. 1. Although not shown, the multiplexed laser beam control system 1100 may also include a control computer 52. In some examples, the control computer 52 is communicatively coupled to one or more of the laser generator 12, the dynamic focus module 1102, the multiplexer 1104, and the beam scanning module 1106.

[0057] In this example, the dynamic focus device 1102 receives the laser beam 1101 from the laser generator 12 and is operable to provide an independent focus (e.g., via a focusing lens) of the received laser beam 1101. For example, the control computer 52 can cause the dynamic focus device 1102 to adjust the focus of the received laser beam 1101. The dynamic focus device 1102 directs the focused laser beam to a multiplexer 1104.

[0058] The multiplexer 1104 may be a time multiplexer (e.g., route the laser beam between various paths on a time basis) or a space multiplexer (e.g., route the laser beam between various paths simultaneously). The multiplexer 1104 may operate, for example, temporally, spatially, or spatiotemporally. In some examples, the control computer 52 configures the multiplexer 1104 to route the laser beam between various paths, for example to the beam scanning device 1106. Multiplexing the laser beam may provide one or more advantages, such as enabling scaling of the laser beam control system 1100 for large draws using a single laser generator 12.

[0059] In some examples, rather than the dynamic focus device 1102 being positioned between the laser generator 12 and the multiplexer 1104 (as is the case, for example, when the multiplexer 1104 is a time multiplexer), the dynamic focus device 1102 is positioned along a path from the multiplexer 1104 to each beam scanning device 1106.

[0060] Each beam scanning device 1106 may be, for example, a reflector 14. In some examples, each beam scanning device 1106 may be a diffractive optical element, an acousto-optic modulator, or other optical and electronic scanning device. Each beam scanning device 1106 may receive a laser beam from the multiplexer 1104 and scan the laser beam over a portion of the molten glass 1150 to heat the respective portion of the molten glass. In this example, each beam scanning device 1106 covers approximately ¼ of the molten glass 1150, although in some examples, the portion of the molten glass covered by one beam scanning device 1106 may overlap the portion of the molten glass covered by another beam scanning device 1106.

[0061] In some examples, each beam scanning device 1106 is communicatively coupled to a dynamic focus device 1102. The dynamic focus device 1102 can refocus the laser beam based on which beam scanning device 1106 is active. Each beam scanning device 1106 can be synchronized with the dynamic focus device 1102, such as when the multiplexer 1104 is simultaneously splitting the laser beam among the various beam scanning devices.

[0062] In some examples, each beam scanning device 1106 is positioned at a known distance and angle relative to the multiplexer 1104. For example, the control computer 52 may determine the distance and angle from the multiplexer to each beam scanning device 1106, for example, based on user input or based on retrieving data from a database. The control computer 52 may configure the power density of the laser beam based on the distance and angle from the multiplexer to each active beam scanning device 1106.

[0063] For example, control computer 52 may configure laser generator 12 to adjust the power density of the laser beam based on the angle of incidence of the laser beam to the molten glass 1150. For example, multiplexed laser beam control system 1100 can compensate for a decrease in power density of the laser beam delivered to the molten glass 1150 due to the angle of incidence of the laser beam to the molten glass 1150. As another example, multiplexed laser beam control system 1100 can compensate for a decrease in absorption of laser energy due to the angle of incidence of the laser beam to the molten glass 1150. Thus, multiplexed laser beam control system 1100 maintains the same power density as each beam scanning device 1106 scans the molten glass 1150 with a laser beam.

[0064] In some examples, the multiplexed laser beam control system 1100 compensates for any lateral displacement that occurs to the laser beam as it advances through a window, such as window 504 in FIG. 5. In some examples, the multiplexed laser beam control system 1100 shapes the generated laser beam to have sharp edges. In some examples, the multiplexed laser beam control system 1100 stretches the generated laser beam (e.g., in the draw direction) to minimize or eliminate any gaps as each beam scanning device 1106 scans the molten glass 1150 with the laser beam. In some examples, the multiplexed laser beam control system 1100 stretches the laser beam in the scan direction to minimize or eliminate gaps in the application of the laser beam to the molten glass 1150. In some examples, the multiplexed laser beam control system 1100 adjusts where the waist of the laser beam occurs by redirecting the path of the laser beam (e.g., via one or more multiplexers).

[0065] In some examples, the multiplexed laser beam control system 1100 may include an additional laser generator 12 to generate an additional laser beam for heating a portion of the molten glass 1150. For example, the laser beam control system 1100 may use a second laser generator 12, a second dynamic focus device 1102, and a second multiplexer 1104 to direct the laser beam generated by the second dynamic focus device 1102 to the portion of the molten glass 1150 via a beam scanning device 1106. The use of an additional laser generator 12 may reduce the time required to heat a portion (e.g., the entirety) of the molten glass 1150.

[0066] 12 shows portions of a multiplexed laser beam control system 1200, including multiple beam splitters 1108, multiple reflectors 1110, multiple path compensators 1114 (optional in this example), and multiple beam scanning devices 1106 for directing a laser beam 1101 to the molten glass 1150. The laser beam 1101 can be provided, for example, by a laser generator 12. Although not shown, the multiplexed laser beam control system 1200 may include a controlling computer 52.

[0067] Each path compensator 1114 may be, for example, a static path compensator or a dynamic path compensator. Each path compensator 1114 may delay the laser beam passing through the path compensator. For example, the control computer 52 may configure each path compensator 1114 to delay the laser beam by a certain amount of time.

[0068] Each beam splitter 1108 can split the laser beam between two or more paths. For example, a beam splitter 1108 can split one laser beam along one path to another beam splitter 1108 and along another path to a reflector 1110. In some examples, one beam splitter 1108 can receive multiple laser beams (e.g., from multiple sources simultaneously or in a time-multiplexed manner) and provide the received laser beams along different paths. For example, one beam splitter 1108 can receive a laser beam from a reflector 1110 and from another beam splitter 1108 and provide the received laser beam to the beam scanning device 1106.

[0069] In this example, six beam scanning devices 1106 provide a laser beam to a respective portion of the molten glass 1150. In some examples, control computer 52 configures each of the six beam scanning devices 1106 to direct a laser beam to a respective portion of the molten glass 1150. In some examples, control computer 52 configures each of the six beam scanning devices 1106 to direct a laser beam to a respective non-overlapping portion of the molten glass 1150. In some examples, control computer 52 configures at least two of the six beam scanning devices 1106 to direct a laser beam to multiple overlapping portions of the molten glass 1150.

[0070] 13 shows multiple portions of a multiplexed laser beam control system 1300, including a multiplexer 1112, multiple reflectors 1110, multiple path compensators 1114 (optional in this example), and multiple beam scanning devices 1106, for directing a laser beam 1101 to the molten glass 1150. A path compensator 1114, such as a focus path compensator, can be used to re-adjust the focal length of the optical path so that the laser beam is still focused on the glass. The laser beam 1101 can be provided, for example, by a laser generator 12. Although not shown, the multiplexed laser beam control system 1300 may include a controlling computer 52.

[0071] In this example, the laser beam 1101 optionally travels through a first path compensator 1114 before reaching a multiplexer 1112, which may be a time multiplexer or a division multiplexer. Depending on the configuration of the multiplexer 1112, the laser beam may travel along one path or two paths. Along one path, the laser beam travels through a second path compensator 1114 to a reflector (which may be configured by the control computer 52) before reaching a beam scanning device 1106. The beam scanning device 1106 provides the laser beam to a portion of the molten glass 1150. Along the other path, the laser beam travels to a reflector (which may be configured by the control computer 52) before reaching the beam scanning device 1106. The beam scanning device 1106 provides the laser beam to different portions of the molten glass 1150.

[0072] 14 shows portions of a multiplexed laser beam control system 1400 including multiple beam splitters 1108, multiple reflectors 1110, multiple path compensators 1114 (optional in this example), and multiple beam scanning devices 1106 for directing a laser beam 1101 (e.g., from a laser generator 12, not shown) to molten glass 1150. Although not shown, the multiplexed laser beam control system 1400 may also include a controlling computer 52.

[0073] In this example, depending on the configuration of multiplexed laser beam control system 1400, laser beam 1101 can advance along a path that includes multiple reflectors 1110, each of which can be configured by control computer 52. Further, each beam scanning device can be configured to direct the laser beam at different portions of molten glass 1150. In some examples, the portions of molten glass can overlap one another.

[0074] 15 shows portions of a multiplexed laser beam control system 1500 including multiple beam splitters 1108, multiple reflectors 1110, multiple path compensators 1114, and multiple beam scanning devices 1106 for directing a laser beam 1101 (e.g., from a laser generator 12, not shown) to molten glass 1150. Although not shown, the multiplexed laser beam control system 1500 may include a controlling computer 52.

[0075] In this example, depending on the configuration of the multiplexed laser beam control system 1500, the laser beam 1101 can advance along a path that includes multiple reflectors 1110, each of which can be configured by the control computer 52. In some examples, the path includes a path compensator 1114. Further, each beam scanning device can be configured to direct the laser beam to different portions of the molten glass 1150. In some examples, the portions of the molten glass can overlap each other. In some examples, multiple beam scanning devices 1106 are active simultaneously, thereby heating the molten glass 1150 at different portions. In some examples, a subset of the beam scanning devices 1106 are active at any one time. For example, the control computer 52 can configure the multiplexed laser beam control system 1500 to have every other beam scanning device 1106 active at a time.

[0076] FIG. 16 illustrates an exemplary method that may be implemented by one or more computing devices, such as the control computer 52. By implementing the method, the thickness of the molten glass ribbon may be adjusted. In some examples, the method is implemented continuously as the laser beam scans the glass. For example, calculations may be implemented continuously as the laser beam scans the glass surface to continuously adjust the laser beam power (and / or laser beam shape, focus, etc.) as the glass is formed. First, in step 1602, a position of the reflector 14 of the glass forming apparatus 20 may be determined relative to the molten glass to be heated by the laser beam. In step 1604, an expected angle of incidence of the laser beam reflected from the reflector 14 onto the molten glass is determined. In step 1606, a power density for the laser beam is calculated based on the calculated angle of incidence. For example, the control computer 52 may determine the power density for the laser beam based on a target thickness profile or target temperature profile for the molten glass and the angle of incidence. Proceeding to step 1608, the laser generator 12 is configured to generate a laser beam having the calculated power density. In step 1610, a portion of the molten glass is heated with the generated laser beam for a predetermined amount of time. In some examples, the laser beam is moved continuously during scanning while dynamically adjusting its power.

[0077] In step 1612, a determination is made as to whether a predetermined length of the molten glass has been heated. For example, a determination is made as to whether the entire length minus the edge portion 48 has been heated. If the predetermined length of the molten glass has been heated, the method ends. Otherwise, if the predetermined length of the molten glass has not been heated, the method proceeds to step 1614, where the position of the reflector 14 is adjusted. For example, the reflector 14 is adjusted so that the generated laser heats a different portion of the molten glass. The method then proceeds back to step 1604.

[0078] 17 illustrates an exemplary method that may be implemented by one or more computing devices, such as the control computer 52. Beginning at step 1702, a multiplexer 1104 is configured to provide a laser beam to a plurality of beam scanning devices 1106. At step 1704, a dynamic focus device is synchronized to the plurality of beam scanning devices 1106. At step 1706, a laser generator 12 is configured to generate a laser beam that advances from the laser generator 12 to the multiplexer 1104 and from the multiplexer 1104 to at least one of the plurality of beam scanning devices 1106. At step 1708, a portion of the molten glass is heated by the laser beam from the at least one of the plurality of beam scanning devices 1106. The method then ends.

[0079] Although the methods described above refer to illustrated flow charts, it will be appreciated that many other ways of performing the acts associated with the methods may be used, for example, the order of some operations may be changed, and some of the operations described above may be optional.

[0080] Furthermore, the methods and systems described herein may be embodied, at least in part, in the form of computer-implemented processes and apparatuses for carrying out these processes. The methods of the present disclosure may also be embodied, at least in part, in the form of a tangible non-transitory machine-readable storage medium encoded with computer program code. For example, the steps of the method may be embodied in hardware; in executable instructions (e.g., software) executed by a processor; or in a combination of the two. The medium may include, for example, a RAM, a ROM, a CD-ROM, a DVD-ROM, a BD-ROM, a hard disk drive, a flash memory, or any other non-transitory machine-readable storage medium. When the computer program code is loaded and executed by a computer, the computer becomes an apparatus for carrying out the method. The method may also be embodied, at least in part, in the form of a computer that can load or execute the computer program code, thereby making the computer a dedicated computer for carrying out the method. When implemented on a general-purpose processor, the computer program code segments configure the processor to create specific logic circuits. Alternatively, the method may be embodied, at least in part, in an application-specific integrated circuit for carrying out the method.

[0081] The foregoing has been provided for the purposes of illustrating, illustrating, and describing embodiments of the present disclosure. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and can be made without departing from the scope or spirit of the present disclosure.

[0082] Preferred embodiments of the present invention will be described below in detail.

[0083] EMBODIMENT 1 a memory device for storing instructions; and a controller comprising at least one processor and configured to execute the instructions; An apparatus comprising: The above command will be sent to the controller: preselecting a portion of molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam to the preselected portion of the molten glass; activating the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass. A device that performs the above.

[0084] EMBODIMENT 2 2. The apparatus of embodiment 1, wherein the controller is configured to determine the angle of incidence of the laser beam relative to the preselected portion of the molten glass based on a position of the reflecting device.

[0085] EMBODIMENT 3 The above controller: determining an amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass based on the angle of incidence; determining the power density for the laser beam based on an amount of the laser energy of the laser beam to be reflected from the preselected portion of the molten glass; 2. The apparatus of embodiment 1, configured to:

[0086] EMBODIMENT 4 The above controller: determining a lateral displacement that the laser beam will undergo when directed through at least one window; Configuring the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass based on the determined lateral displacement. 2. The apparatus of embodiment 1, configured to:

[0087] EMBODIMENT 5 The above controller: determining a path length traveled by the laser beam from the reflector to the preselected portion of the molten glass; Configuring the laser generator to generate the laser beam having a beam waist positioned at the preselected portion of the molten glass. 2. The apparatus of embodiment 1, configured to:

[0088] EMBODIMENT 6 The above controller: configuring the reflector to reflect the laser beam from the laser generator to another preselected portion of the molten glass; determining a path length traveled by the laser beam from the reflector to the other preselected portion of the molten glass; 6. The apparatus of embodiment 5, configured to:

[0089] EMBODIMENT 7 2. The apparatus of embodiment 1, wherein the controller is configured to configure a multiplexer to direct the laser beam to a plurality of beam scanning devices, each of the plurality of beam scanning devices capable of heating a respective portion of the preselected portion of the molten glass with the laser beam.

[0090] EMBODIMENT 8 a laser generator operable to generate a laser beam; a reflector configured to reflect the laser beam from the laser generator to molten glass in a glass forming device; and a controller communicatively coupled to the laser generator and the reflector; An apparatus comprising: The above controller: configuring said glass forming apparatus to preselect a portion of said molten glass; configuring the reflector to reflect the laser beam from the laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam with respect to the preselected portion of the molten glass; activating the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass. The apparatus is configured as follows.

[0091] EMBODIMENT 9 9. The apparatus of embodiment 8, wherein the controller is configured to determine the angle of incidence of the laser beam relative to the preselected portion of the molten glass based on a position of the reflecting device.

[0092] EMBODIMENT 10 The apparatus includes a multiplexer and a plurality of beam scanning devices; 9. The apparatus of embodiment 8, wherein the controller is configured to configure the multiplexer to direct the laser beam to a plurality of beam scanning devices, each of the plurality of beam scanning devices capable of heating a respective portion of the preselected portion of the molten glass with the laser beam.

[0093] EMBODIMENT 11 9. The apparatus of embodiment 8, wherein the apparatus comprises a dynamic focus device, and the laser generator is configured to direct the generated laser beam to the dynamic focus device.

[0094] EMBODIMENT 12 12. The apparatus of embodiment 11, wherein the controller is configured to synchronize the dynamic focus device with the multiple beam scanning devices.

[0095] EMBODIMENT 13 9. The apparatus of embodiment 8, wherein the apparatus comprises at least one beam splitter, the at least one beam splitter configured to direct the laser beam to at least one of the plurality of beam scanning devices.

[0096] EMBODIMENT 14 An apparatus as described in embodiment 13, wherein the apparatus comprises a second beam splitter, and the at least one beam splitter is configured to direct the laser beam to the second beam splitter, and the second beam splitter is configured to direct the laser beam to at least a second of the plurality of beam scanning devices.

[0097] EMBODIMENT 15 15. The apparatus of embodiment 14, wherein the apparatus comprises a second reflecting device, and the second beam splitter is configured to direct the laser beam to the second reflecting device.

[0098] EMBODIMENT 16 1. A method for heating molten glass, the method comprising: drawing the molten glass from a forming device; preselecting a portion of the molten glass; configuring a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam with respect to the preselected portion of the molten glass; and heating the preselected portion of the molten glass by operating the laser generator to generate the laser beam at the determined power density. A method comprising:

[0099] EMBODIMENT 17 17. The method of embodiment 16, wherein the angle of incidence is based on a position of the reflector.

[0100] EMBODIMENT 18 determining an amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass based on the angle of incidence; and determining the power density for the laser beam based on an amount of the laser energy of the laser beam to be reflected from the preselected portion of the molten glass. 17. The method of embodiment 16, further comprising:

[0101] EMBODIMENT 19 determining a lateral displacement that the laser beam will undergo as it advances through at least one window; and configuring the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass based on the determined lateral displacement. 17. The method of embodiment 16, further comprising:

[0102] EMBODIMENT 20 determining a path length traveled by the laser beam from the reflector to the preselected portion of the molten glass; and configuring the laser generator to generate the laser beam having a beam waist positioned at the preselected portion of the molten glass. 17. The method of embodiment 16, further comprising:

[0103] EMBODIMENT 21 17. The method of embodiment 16, wherein the step of configuring the reflector includes a step of determining a raster pattern for applying the laser beam to the preselected portion of the glass forming apparatus, the method further including a step of operating the laser generator according to the determined raster pattern.

[0104] EMBODIMENT 22 17. The method of embodiment 16, wherein the step of configuring the reflecting device includes a step of receiving position data from a position sensor that identifies a position of the reflecting device, and the method further includes a step of performing at least one of rotating or tilting a reflective surface of the reflecting device based on the received position data.

[0105] EMBODIMENT 23 1. A method for controlling heating of molten glass, the method comprising: preselecting a portion of said molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam with respect to the preselected portion of the molten glass; and heating the preselected portion of the molten glass by operating the laser generator to generate the laser beam at the determined power density. A method comprising:

[0106] EMBODIMENT 24 24. The method of embodiment 23, wherein the angle of incidence is based on a position of the reflector.

[0107] EMBODIMENT 25 determining an amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass based on the angle of incidence; and determining the power density for the laser beam based on an amount of the laser energy of the laser beam to be reflected from the preselected portion of the molten glass. 24. The method of embodiment 23, further comprising:

[0108] EMBODIMENT 26 determining a lateral displacement that the laser beam will undergo as it advances through at least one window; and configuring the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass based on the determined lateral displacement. 24. The method of embodiment 23, further comprising:

[0109] EMBODIMENT 27 determining a path length traveled by the laser beam from the reflector to the preselected portion of the molten glass; and configuring the laser generator to generate the laser beam having a beam waist positioned at the preselected portion of the molten glass. 24. The method of embodiment 23, further comprising:

[0110] EMBODIMENT 28 24. The method of embodiment 23, wherein the step of configuring the reflector includes a step of determining a raster pattern for applying the laser beam to the preselected portion of the glass forming apparatus, the method further including a step of operating the laser generator according to the determined raster pattern.

[0111] EMBODIMENT 29 24. The method of embodiment 23, wherein the step of configuring the reflecting device includes a step of receiving position data from a position sensor that identifies a position of the reflecting device, and the method further includes a step of performing at least one of rotating or tilting a reflective surface of the reflecting device based on the received position data.

[0112] EMBODIMENT 30 1. A method for controlling a laser beam to vary a thickness of a molten glass sheet, the method comprising: providing a controller comprising at least one processor and configured to execute instructions; communicatively coupling the controller to a laser generator, a dynamic focus module, a multiplexer, a first beam scanning module, and a second beam scanning module; Receiving a first instruction at the controller, causing the controller to: selecting a first target area of ​​the molten glass sheet; determining a first path length of the laser beam through the first beam scanning module to the first target area; configuring the multiplexer to reflect the laser beam via the first path to the first target area; adjusting the dynamic focus module to provide a first focal point for the laser beam based on the first path length; and activating the laser generator to emit a first laser beam pulse to heat the first target area. and Receiving a second instruction at the controller, causing the controller to: selecting a second target area of ​​the molten glass sheet; determining a second path length of the laser beam through the second beam scanning module to the target area; configuring the multiplexer to reflect the laser beam via the second path to the second target area; adjusting the dynamic focus module to provide a second focal point for the laser beam based on the second path length; and activating the laser generator to emit a second laser beam pulse to heat the second target area. execute the step A method comprising:

[0113] EMBODIMENT 31 31. The method of embodiment 30, wherein the first target area and the second target area at least partially overlap.

[0114] EMBODIMENT 32 31. The method of embodiment 30, wherein the first instructions in the controller cause the controller to determine a first power density for the laser beam based on a first angle of incidence of the laser beam to the first target area of ​​the molten glass sheet, and the second instructions in the controller cause the controller to determine a second power density for the laser beam based on a second angle of incidence of the laser beam to the second target area of ​​the molten glass sheet.

[0115] EMBODIMENT 33 31. The method of claim 30, wherein the first instructions in the controller cause the controller to configure the laser generator to generate a first laser beam pulse having a first beam waist positioned at the first target area of ​​the molten glass sheet, and the second instructions in the controller cause the controller to configure the laser generator to generate a second laser beam pulse having a second beam waist positioned at the second target area of ​​the molten glass sheet.

[0116] EMBODIMENT 34 31. The method of embodiment 30, wherein the first instruction in the controller causes the controller to synchronize the dynamic focus module with the first beam scanning module, and the second instruction in the controller causes the controller to synchronize the dynamic focus module with the second beam scanning module.

[0117] EMBODIMENT 35 31. The method of embodiment 30, wherein the first instruction in the controller causes the controller to determine the first path length of the laser beam through a first beam splitter to the first target area, and the second instruction in the controller causes the controller to determine the second path length of the laser beam through a second beam splitter to the second target area.

[0118] EMBODIMENT 36 communicatively coupling the controller to a reflector; The first instruction in the controller causes the controller to: determining a first lateral displacement that the laser beam will undergo as it advances through a first window; and configuring the reflector to reflect the laser beam from the laser generator to the first beam scanning module based on the determined first lateral displacement. Run the command, The second instruction in the controller causes the controller to: determining a second lateral displacement experienced by the laser beam as it advances through a second window; and configuring the reflector to reflect the laser beam from the laser generator to the second beam scanning module based on the determined second lateral displacement. 31. The method of embodiment 30, wherein the method comprises: [Explanation of symbols]

[0119] 10 Laser Beam Control System 12 Laser Generator 13, 302, 502, 602, 608, 802, 1101 Laser beam 14, 1110 Reflector 15 reflective surface 16 Adjustment mechanism 17 Reflected laser beam 18 Rotating shaft 18a axis 20 Glass forming equipment 22 Molding Wedge 24 Open Channels 25, 26 Wall 27, 28 Overflow Weir 30 Nearly vertical molding surface 32 Downwardly inclined converging forming surface 34 Base 38 Delivery Corridor 40 Dam 42 Free surface of molten glass 44 Glass Ribbon 46 Traction Roll 48 Side edge 50 Edge direction determiner 52 Control computer 55 Laser output control unit 304, 306 Laser beam shape 504 Windows 604, 610 Laser beam profile 804, 1150 Molten Glass 806 Laser Beam Waist 810 Laser beam source 1100, 1200, 1300, 1400, 1500 Multiplexed Laser Beam Control System 1102 Dynamic focus device, dynamic focus module 1104, 1112 multiplexer 1106 Beam scanning device, beam scanning module 1108 Beam splitter 1114 Path compensator, first path compensator, second path compensator

Claims

1. a memory device storing instructions; and a controller comprising at least one processor and configured to execute the instructions; An apparatus comprising: The instructions to the controller: preselecting a portion of molten glass in a glass forming apparatus; configuring a reflector to reflect a laser beam from a laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam to the preselected portion of the molten glass; activating the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass. Run the command, The controller: determining a path length traveled by the laser beam from the reflector to the preselected portion of the molten glass; Configuring the laser generator to generate the laser beam having a beam waist positioned at the preselected portion of the molten glass. The apparatus is configured to:

2. 10. The apparatus of claim 1, wherein the controller is configured to determine the angle of incidence of the laser beam relative to the preselected portion of the molten glass based on a position of the reflecting device.

3. The controller: determining an amount of laser energy of the laser beam to reflect from the preselected portion of the molten glass based on the angle of incidence; determining the power density for the laser beam based on an amount of the laser energy of the laser beam to be reflected from the preselected portion of the molten glass; The apparatus of claim 1 , configured to:

4. The controller: determining a lateral displacement that the laser beam will undergo when directed through at least one window; Configuring the reflector to reflect the laser beam from the laser generator to the preselected portion of the molten glass based on the determined lateral displacement. The apparatus of claim 1 , configured to:

5. The controller: configuring the reflector to reflect the laser beam from the laser generator to another preselected portion of the molten glass; determining a path length traveled by the laser beam from the reflector to the other preselected portion of the molten glass; The apparatus of claim 1 , configured to:

6. 2. The apparatus of claim 1, wherein the controller is configured to configure a multiplexer to direct the laser beam to a plurality of beam scanning devices, each of the plurality of beam scanning devices capable of heating a respective portion of the preselected portion of the molten glass with the laser beam.

7. a laser generator operable to generate a laser beam; Dynamic focus device; a reflector configured to reflect the laser beam from the laser generator to molten glass in a glass forming device; and a controller communicatively coupled to the laser generator and the reflector; An apparatus comprising: the laser generator is configured to direct the generated laser beam towards the dynamic focus device; The controller: configuring the glass forming apparatus to preselect a portion of the molten glass; configuring the reflector to reflect the laser beam from the laser generator onto the preselected portion of the molten glass; determining a power density for the laser beam based on an angle of incidence of the laser beam with respect to the preselected portion of the molten glass; activating the laser generator to generate the laser beam at the determined power density to heat the preselected portion of the molten glass. The apparatus is configured as follows.

8. 8. The apparatus of claim 7, wherein the controller is configured to determine the angle of incidence of the laser beam relative to the preselected portion of the molten glass based on a position of the reflecting device.

9. The apparatus includes a multiplexer and a plurality of beam scanning devices; 8. The apparatus of claim 7, wherein the controller is configured to configure the multiplexer to direct the laser beam to a plurality of beam scanning devices, each of the plurality of beam scanning devices capable of heating a respective portion of the preselected portion of the molten glass with the laser beam.

10. The apparatus of claim 9 , wherein the controller is configured to synchronize the dynamic focus device with the multiple beam scanning devices.

11. 10. The apparatus of claim 9, wherein the apparatus comprises at least one beam splitter, the at least one beam splitter configured to direct the laser beam to at least one of the plurality of beam scanning devices.

12. 12. The apparatus of claim 11, wherein the apparatus comprises a second beam splitter, the at least one beam splitter configured to direct the laser beam to the second beam splitter, the second beam splitter configured to direct the laser beam to at least a second of the plurality of beam scanning devices.

13. The apparatus of claim 12 , wherein the apparatus comprises a second reflecting apparatus, and the second beam splitter is configured to direct the laser beam toward the second reflecting apparatus.

Images