Laser thickness control of fused glass

Abstract

A system for forming a glass ribbon is provided, comprising a glass molded body for forming glass and a first laser module. The glass molded body is configured to allow molten glass to flow along the surface of the glass molded body to form a glass ribbon. The glass ribbon defines a first surface having a width extending from a first edge to a second edge. The first laser module is configured to generate a first laser beam scanned at least partially along the width of the first surface within a first scanning angle range to apply heat to assist in controlling the thickness of the glass ribbon. The direction of the first laser beam facing the first center within the first scanning angle range strikes the first surface at a first center strike angle that is not perpendicular to the first surface.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Application No. 63 / 472903, filed on June 14, 2023, under Section 119 of the U.S. Patent Act, the contents of which are relied upon and incorporated herein by reference in their entirety.

[0002] The embodiments generally relate to systems and methods for mounting one or more laser modules such that the laser beam strikes a molten glass surface at an angle that is not perpendicular. [Background technology]

[0003] Ribbon thickness control in glass forming is typically addressed by cooling the glass ribbon in the glass forming mechanism with airflow from multiple airflow tubes, based on feedback from a thickness measuring gauge. However, these actuators have limitations due to their low spatial resolution and slow response speed. This imposes limitations on the best sheet thickness performance that can be efficiently achieved. Furthermore, the sheet thickness of glass products is often controlled manually. In manual control, the line operator observes the sheet thickness and changes the airflow applied to the glass ribbon by manually changing the position of the airflow valves one at a time to achieve the desired thickness profile. This process is cumbersome and often takes a lot of time for the line operator to complete, as there may be around 200 or more airflow valves in each stretch.

[0004] The aforementioned improvements are desirable. [Overview of the Initiative]

[0005] Precision thickness control systems have also been used to enable high-resolution thickness control across the surface of molten glass during glass forming. Precision thickness control technology directs a laser beam toward the molten glass. The laser beam is absorbed by the molten glass, increasing its temperature. This temperature increase causes a decrease in the viscosity of the molten glass material, creating a new surface tension equilibrium in the molten glass. This new surface tension equilibrium is established after a set zone, resulting in a decrease in the thickness of the molten glass.

[0006] Access is often restricted to locations where the implementation of a precision thickness control system is most effective (e.g., near the root level). Existing structures and cables present significant challenges in securely mounting a precision thickness control system to glassmaking equipment for high-resolution thickness control. Furthermore, a single precision thickness control system typically cannot provide complete coverage across a standard glass forming mechanism. Therefore, multiple tools are likely to be required to control the thickness across the entire width of the molten glass ribbon using standard tools mounted in a standard orientation (perpendicular to the glassmaking equipment).

[0007] The various embodiments discussed herein describe approaches for optimally integrating a precision thickness control platform into glass manufacturing equipment. This disclosure proposes a strategy for positioning / stitching thickness control platform modules to optimize the glass ribbon coverage required to obtain complete thickness control coverage across the surface of molten glass and to minimize capital investment.

[0008] The various embodiments discussed herein envision approaches to positioning the laser module such that the laser beam generated from the laser module is emitted in an orientation not perpendicular to the surface of the molten glass. In some embodiments, the laser beam is emitted at an angle of up to approximately 50 degrees from a direction perpendicular to the surface of the molten glass to increase the coverage of a single laser module. The laser beam may also be scanned across the surface of the molten glass over a scanning angle range, with a central strike angle defined in the middle of this scanning angle range. This central strike angle may be angularly shifted from a direction perpendicular to the surface of the molten glass (e.g., to provide “off-axis” scanning).

[0009] Positioning laser modules in this manner can create problems with optical effects introduced by increased propagation distance and large incident angles; however, the various embodiments considered herein attempt to address these optical effects. These features may enable the embodiments considered herein to effectively control the thickness of molten glass during glass forming to achieve high-resolution thickness control across the entire width of the molten glass ribbon, which can be achieved while reducing the total capital investment required, for example, by using a smaller number of laser modules overall. In addition, when fewer laser modules are used, the area adjacent to the molten glass may become less congested (as space and access around the glass manufacturing equipment are limited due to safety standards, temperature values, and other control features, etc.).

[0010] The various embodiments discussed herein relate to methods for compensating for optical phenomena and distortions caused by such off-axis laser beam scanning. These embodiments may use static focus compensators and / or dynamic focus compensators in a precision thickness control system to compensate for beam divergence and maintain equal fluence across the scanning field, when the system aperture value is about 0.01 or greater. The precision thickness control system may include a spatial light modulator (SLM) or a diffractive optical element (DOE) to compensate for cosine errors caused by large strike angles on glass. The precision thickness control system may also include an acousto-optic modulator or electro-optic modulator for rapidly adjusting Fresnel reflection and / or laser energy loss at scanning speeds of about 1 kilohertz to about 1 megahertz. The scanning speed may be about 1 kilohertz to about 10 kilohertz in some embodiments. The precision thickness control system may rapidly modulate the laser energy using an acousto-optic modulator and / or electro-optic modulator to minimize overshoot and / or undershoot caused by internal inter-pulse variations between triggers.

[0011] The various embodiments discussed herein simplify the integration of precision thickness control modules and reduce clutter around glass manufacturing equipment. For example, the reduced use of tools or other structures / mechanisms leads to a decrease in the likelihood of creating physical obstructions to the laser beam path, thereby reducing and / or eliminating costly redesigns of critical glass forming components. Furthermore, the reduced use of tools or other structures / mechanisms may lead to a reduction in the weight load on the glass manufacturing equipment and a decrease in the likelihood of components in the glass forming mechanism sagging or being damaged. In addition, the reduced use of tools or other structures / mechanisms may lead to reduced maintenance and reduced downtime for manufacturing in events where modules need to be repaired or replaced.

[0012] Glass formed using the systems and methods described herein may be beneficial for use in glass hard disk drive substrate products, automotive glass products, and other glass products. In addition, the various embodiments considered herein can minimize beam distortion during laser scanning, improve thickness control, and reduce processing variations across glass ribbons. Furthermore, the various embodiments considered herein can improve stability between laser pulses and minimize variable pulse overshoot and / or undershoot during operation, thereby resulting in greater process control and repeatability during operation. This may result in higher quality glass with finer thickness control capabilities.

[0013] Various exemplary embodiments utilize precision thickness control techniques that, conversely to regulating the airflow, regulate heat from a laser system driven by a galvanometer-based steering mirror (e.g., "Garbo"). Thus, the laser beam control system can be used in combination with a precision thickness control laser actuator to reduce sheet thickness variations during stretching via closed-loop feedback control. Inputs to the thickness uniformity control unit(s) include a thickness profile target (typically a flat thickness profile) and the current sheet thickness profile measured by a thickness gauge. The output of the controller is a new laser power profile, which can be transmitted to the laser and galvanometer control unit(s). Such precision thickness control systems offer the potential for high-resolution thickness control because the laser can be precisely directed across the glass ribbon and its energy can be precisely controlled. Recent tests using precision thickness control systems have demonstrated that such systems can achieve full width at half maximum resolutions of less than 15 millimeters and thickness control better than 1 micron.

[0014] In an exemplary embodiment, a system for forming a glass ribbon is provided. The system comprises a glass molded body for forming glass and a first laser module. The glass molded body is configured to allow molten glass to flow along the surface of the glass molded body to form a glass ribbon. The glass defines a first surface having a width extending from a first edge to a second edge. The first laser module is configured to generate a first laser beam scanned at least partially along the width of the first surface within a first scanning angle range to apply heat to assist in controlling the thickness of the glass ribbon. The direction of the first laser beam facing the first center within the first scanning angle range strikes the first surface at a first center strike angle that is not perpendicular to the first surface.

[0015] In some embodiments, the first laser beam may be spread at least partially along the width of the glass ribbon between the first edge and the second edge. The first scanning angle range may be equal to the angular range between the first scanning angle and the second scanning angle, where the first scanning angle is the minimum angle at which a portion of the first laser beam strikes the first surface, and the second scanning angle is the maximum angle at which a portion of the first laser beam strikes the first surface. In addition, in some embodiments, the first scanning angle range may be greater than about 40 degrees.

[0016] In some embodiments, the first central strike angle may be measured with respect to the normal direction of the first surface, and the first central strike angle is greater than zero degrees and less than about 50 degrees. In some embodiments, the first laser beam may cause a temperature increase in the glass ribbon in the affected region. The temperature increase may cause a decrease in the viscosity of the glass ribbon in the affected region, and the decrease in the viscosity of the glass ribbon may result in a decrease in the thickness of the glass ribbon in the affected region.

[0017] In some embodiments, the system may further comprise a second laser module, which may be configured to generate a second laser beam scanned at least partially along the width of the first surface within a second scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon. The system may be configured such that the direction of the second laser beam facing the second center within the second scanning angle range strikes the first surface at a second center strike angle. In addition, in some embodiments, the first center strike angle and the second center strike angle may be the same. Furthermore, in some embodiments, the first center strike angle and the second center strike angle may be different. In some embodiments, the second center strike angle may be equal to zero.

[0018] In some embodiments, the system may further comprise at least one optical element. The first laser module may be configured to radiate a first laser beam toward at least one optical element, and the at least one optical element may be configured to redirect the first laser beam toward a first surface. In addition, in some embodiments, the at least one optical element may comprise a reflector. Furthermore, the system may also comprise an adjustment mechanism configured to adjust the orientation of at least one optical element. Adjusting the orientation of at least one optical element may cause a change in the position where the laser beam contacts the first surface of the glass ribbon.

[0019] In some embodiments, the system may also include a thickness sensor and a thickness control unit. The thickness sensor may be configured to determine the thickness of the glass ribbon at one or more locations. The thickness control unit may be configured to receive thickness data from the thickness sensor based on the thickness of the glass ribbon at one or more locations. The thickness control unit may be configured to receive a target thickness profile, and may be configured to generate a power profile based on at least the thickness data and the target thickness profile. The power profile may be configured to be used to control the operation of the first laser module. In addition, in some embodiments, the glass ribbon responds to the laser power according to a Gaussian response model, a double Gaussian response model, or a response model based on a raised cosine function or a Bessel function. Furthermore, in some embodiments, the target thickness profile may maintain a uniform thickness across the width of the glass ribbon. In some embodiments, the target thickness profile may maintain a variable thickness across the width of the glass ribbon.

[0020] In some embodiments, the system may further include at least one of an acousto-optic modulator or an electro-optic modulator, and the acousto-optic modulator and the electro-optic modulator may be configured to modulate the generated laser beam to produce a first laser beam. In addition, in some embodiments, the acousto-optic modulator and the electro-optic modulator may be configured to cause the system to maintain a more uniform energy density on the first surface compared to other identical systems that do not include an acousto-optic modulator or an electro-optic modulator. Furthermore, in some embodiments, the first central strike angle may be equal to about 30 degrees, and the first laser beam may strike the first surface at minimum and maximum energy densities, with the minimum energy density being less than about 21 percent of the maximum energy density.

[0021] In some embodiments, the system may further comprise at least one of a spatial light modulator or a diffractive optical element, which may be configured to compensate for cosine errors caused by large glass incidence angles. In some embodiments, the glass molded body may include a root, and the first laser beam may strike a first surface below the root of the glass molded body. In some embodiments, the glass molded body may include a root, and the first laser beam may strike a first surface above the root of the glass molded body. In some embodiments, the first laser beam may comprise light having a wavelength of about 400 nanometers to about 11,000 nanometers.

[0022] In another exemplary embodiment, a method is provided for manufacturing a system for providing laser thickness control. The method comprises providing a glass molded body for forming glass, the glass molded body being configured to allow molten glass to flow along at least one surface of the glass molded body to form a glass ribbon. The glass ribbon defines a first surface having a width extending from a first edge to a second edge. The method may also comprise a first laser module configured to generate a first laser beam scanned at least partially along the width of the first surface within a scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon being formed into glass. The method may also comprise positioning the first laser module so as to direct the first laser beam toward the first surface. The first surface defines a normal direction perpendicular to the first surface, and the system is configured such that the direction of the first laser beam facing the center of the scanning angle range strikes the first surface at a central strike angle that is not perpendicular to the first surface. In some embodiments, the method may also include providing a second laser module configured to generate a second laser beam scanned at least partially along the width of a first surface within a second scanning angle range, so as to apply heat to assist in controlling the thickness of a glass ribbon. The method may also include positioning the second laser module so as to orient the second laser beam toward the first surface.

[0023] In another exemplary embodiment, a laser system for forming a glass ribbon is provided. The laser system comprises a first laser module configured to generate a first laser beam scanned at least partially along the width of a first face of the glass ribbon. Molten glass is configured to flow along the surface of a glass molded body to form the glass ribbon. The molten glass defines a first face having a width extending from a first edge to a second edge. The first laser beam is scanned within a first scanning angle range along the width to apply heat to assist in controlling the thickness of the glass ribbon. The first laser beam is aimed along the width such that the direction facing the first center of the first scanning angle range of the first laser beam strikes the first face at a first central strike angle that is not perpendicular to the first face.

[0024] Please refer to the attached drawing, but the drawing does not necessarily need to be drawn to scale. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic diagram illustrating an exemplary glass manufacturing apparatus according to some embodiments discussed herein. [Figure 2A] This is an illustrative cross-sectional view of an exemplary glass manufacturing apparatus taken along line AA in Figure 1, according to some embodiments discussed herein. [Figure 2B] This is an enlarged view of region C in Figure 2A, according to some embodiments discussed herein. [Figure 2C] This is a schematic diagram illustrating exemplary optical elements used to redirect a laser beam toward the surface of molten glass, according to some embodiments discussed herein. [Figure 3] This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 4]This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 5] This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 6] This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 7] This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 8] This schematic diagram illustrates various exemplary mounting approaches for laser modules according to some embodiments discussed herein. [Figure 9] This is a line graph illustrating the coverage of a molten glass ribbon by a single module when different central strike angles are used in some embodiments discussed herein. [Figure 10] This is a line graph illustrating the number of modules required to obtain complete coverage of a 3.5-meter molten glass ribbon when various center strike angles are used according to some embodiments discussed herein. [Figure 11] This is a piecewise graph illustrating the normalized beam energies fed to the molten glass at different scanning angles when different central strike angles are used and focus compensation is not employed, according to some embodiments discussed herein. [Figure 12] This is a piecewise graph illustrating the normalized beam energies fed to the molten glass at different scanning angles when different central strike angles are used and focus compensation is employed, according to some embodiments discussed herein. [Figure 13] This is a block diagram illustrating an exemplary laser beam control system according to some embodiments discussed herein. [Figure 14] This is a piecewise graph illustrating exemplary Gaussian response models of thickness profile responses according to some embodiments discussed herein. [Figure 15] This is a piecewise line graph illustrating exemplary double Gaussian response models of thickness profile responses according to some embodiments discussed herein. [Figure 16] This is a line graph illustrating exemplary thickness errors before and after optimization in some embodiments discussed herein. [Figure 17A] This is a schematic diagram illustrating laser beams striking a molten glass surface at different angles according to some embodiments discussed herein. [Figure 17B] This is a schematic diagram illustrating laser beams striking a molten glass surface at different angles according to some embodiments discussed herein. [Figure 18A] This schematic diagram illustrates the lengths over which the laser beam travels at various angles before reaching the molten glass material, according to some embodiments discussed herein. [Figure 18B] This schematic diagram illustrates the lengths over which the laser beam travels at various angles before reaching the molten glass material, according to some embodiments discussed herein. [Figure 19] This is a broken line graph illustrating the lengths of the laser beam as it travels at various angles before reaching the glass, according to some embodiments discussed herein. [Figure 20] This flowchart illustrates an exemplary method for manufacturing a laser thickness control system according to some embodiments discussed herein. [Modes for carrying out the invention]

[0026] Hereafter, exemplary embodiments will be described more fully in this specification with reference to the accompanying drawings, which show some, though not all, embodiments. Unless otherwise specifically stated, any connection or attachment may be direct or indirect. As used herein, the terms “the,” “a,” or “an” mean “at least one,” and should not be limited to “only one” unless otherwise expressly indicated to the contrary. Thus, a reference to, for example, “a component” includes embodiments having two or more such components, unless otherwise clearly indicated by the context.

[0027] When used herein, the term “approximately” means that quantities, sizes, formulations, parameters, and other quantities and characteristics are not, and do not need to be, exact, and may be, where desirable, approximate and / or greater or less, reflecting tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art. Where the term “approximately” is used when describing values ​​or endpoints of a range, this disclosure should be understood to include the specific values ​​or endpoints being referenced. Regardless of whether the numerical values ​​or endpoints of a range in the specification cite “approximately,” the numerical values ​​or endpoints of a range are intended to include two embodiments: those modified by “approximately” and those not modified by “approximately.” It will be further understood that each endpoint of a range is important, whether related to or independent of the other endpoints.

[0028] Figure 1 is a schematic diagram illustrating an exemplary glass manufacturing apparatus. As schematically illustrated in Figure 1, in some embodiments, the glass manufacturing apparatus 100 may include a glass forming apparatus 101 which includes a glass molded body 140 designed to produce a glass ribbon 103 from a large amount of molten glass 121. In some embodiments, the glass ribbon 103 may include a central portion 152 positioned between opposing, relatively thick edge beads formed along a first outer edge 153 and a second outer edge 155 of the glass ribbon 103. In addition, in some embodiments, the glass sheet 104 may be separated from the glass ribbon 103 along a separation path 151 by a glass separator 149 (e.g., a scribe, score wheel, diamond tip, laser). In some embodiments, before or after separating the glass sheet 104 from the glass ribbon 103, the relatively thick edge beads formed along the first outer edge 153 and the second outer edge 155 may be removed to provide the central portion 152 as a glass sheet 104 with a more uniform thickness.

[0029] In some embodiments, the glassmaking apparatus 100 may include a melting vessel 105 oriented to receive batch material 107 from a storage bin 109. The batch material 107 may be introduced by a batch feeding device 111 powered by a motor 113. In some embodiments, a controller 115 may optionally operate the motor 113 to introduce a desired amount of batch material 107 into the melting vessel 105, as indicated by an arrow 117. The melting vessel 105 may heat the batch material 107 to produce molten glass 121. In some embodiments, a glass melting probe 119 may be used to measure the level of molten glass 121 in a standpipe 123 and transmit the measured information to the controller 115 via a communication line 125.

[0030] In addition, in some embodiments, the glassmaking apparatus 100 may include a first adjustment station, which includes a clarification vessel 127 located downstream of the molten vessel 105 and coupled to the molten vessel 105 via a first connecting conduit 129. In some embodiments, the molten glass 121 may be supplied by gravity from the molten vessel 105 to the clarification vessel 127 via the first connecting conduit 129. For example, in some embodiments, gravity may drive the molten glass 121 from the molten vessel 105 to the clarification vessel 127 through the internal path of the first connecting conduit 129. In addition, in some embodiments, bubbles may be removed from the molten glass 121 in the clarification vessel 127 by various techniques.

[0031] In some embodiments, the glassmaking apparatus 100 may further include a second adjustment station, which may include a mixing chamber 131 located downstream of the clarification vessel 127. The mixing chamber 131 is used to provide a homogeneous composition of the molten glass 121, thereby reducing or eliminating any heterogeneity that may be present in the molten glass 121 as it exits the clarification vessel 127. As shown, the clarification vessel 127 may be coupled to the mixing chamber 131 via a second connecting conduit 135. In some embodiments, the molten glass 121 may be gravity-fed from the clarification vessel 127 to the mixing chamber 131 via the second connecting conduit 135. For example, in some embodiments, gravity may drive the molten glass 121 from the clarification vessel 127 to the mixing chamber 131 through an internal path of the second connecting conduit 135.

[0032] In addition, in some embodiments, the glassmaking apparatus 100 may include a third regulating station, which may include a feed container 133 located downstream of the mixing chamber 131. In some embodiments, the feed container 133 may be regulated so that molten glass 121 is supplied to an inlet conduit 141. For example, the feed container 133 may function as an accumulator and / or flow controller to regulate and provide a consistent flow of molten glass 121 to the inlet conduit 141. As shown, the mixing chamber 131 may be coupled to the feed container 133 via a third connecting conduit 137. In some embodiments, the molten glass 121 may be gravity-fed from the mixing chamber 131 to the feed container 133 via the third connecting conduit 137. For example, in some embodiments, gravity may drive the molten glass 121 from the mixing chamber 131 to the feed container 133 through an internal path of the third connecting conduit 137. As further illustrated, in some embodiments, the supply pipe 139 may be positioned to supply molten glass 121 to the inlet conduit 141 of the glass molded body 140.

[0033] Various embodiments of a forming vessel may be provided according to the features of this disclosure, including a forming vessel equipped with a wedge for fusion drawing a glass ribbon, a forming vessel equipped with slots for slot drawing a glass ribbon, or a forming vessel equipped with a press roll for press rolling a glass ribbon from the forming vessel. For example, a glass molded body 140 shown and disclosed below may be provided for producing a glass ribbon 103 by fusion drawing molten glass 121 from the root 145 of a forming wedge 110. For example, in some embodiments, molten glass 121 may be fed into the glass molded body 140 from an inlet conduit 141. The molten glass 121 may then be formed into a glass ribbon 103, at least in part, based on the structure of the glass molded body 140. For example, as shown, the molten glass 121 may be stretched from the bottom edge (e.g., root 145) of the glass molded body 140 along a stretching path extending in the stretching direction 154 of the glass manufacturing apparatus 100. In some embodiments, the edge director may direct the molten glass 121 away from the glass molded body 140, defining at least partially the width "W" of the glass ribbon 103. In some embodiments, the width "W" of the glass ribbon 103 may extend between the first outer edge 153 and the second outer edge 155 of the glass ribbon 103.

[0034] In some embodiments, the width "W" of the glass ribbon 103 may be approximately 20 mm or more, approximately 50 mm or more, approximately 100 mm or more, approximately 500 mm or more, approximately 1,000 mm or more, approximately 2,000 mm or more, approximately 3,000 mm or more, or approximately 4,000 mm or more, but in further embodiments, other widths may be provided. In some embodiments, the width "W" of the glass ribbon 103 may be approximately 20 mm to approximately 4,000 mm, approximately 50 mm to approximately 4,000 mm, approximately 100 mm to approximately 4,000 mm, approximately 500 mm to approximately 4,000 mm, approximately 1,000 mm to approximately 4,000 mm, approximately 2,000 mm to approximately 4,000 mm, approximately 3,000 mm to approximately 4,000 mm, approximately 20 mm to approximately 3,000 mm, approximately 50 mm to approximately 3,000 mm, approximately 500 mm to approximately 3,000 mm, approximately 1,000 mm to approximately 3,000 mm, approximately 2,000 mm to approximately 3,000 mm, approximately 2,000 mm to approximately 2,500 mm, and all and partial ranges in between.

[0035] Figure 2A is a cross-sectional view illustrating an exemplary glass manufacturing apparatus taken along line AA in Figure 1. In some embodiments, the glass molded body 140 may include a trough 201 oriented to receive molten glass 121 from an inlet conduit 141. The glass molded body 140 may further include a molding wedge 110 including a pair of downwardly inclined converging surface portions 207A, 207B extending between the opposing ends 110A, 110B (see Figure 1) of the molding wedge 110. The pair of downwardly inclined converging surface portions 207A, 207B of the molding wedge 110 may converge along the stretching direction 154 and intersect along the bottom edge of the molding wedge 110 to define the root 145 of the glass molded body 140. The stretching plane 213 of the glass manufacturing apparatus 100 may extend along the stretching direction 154 through the root 145. In some embodiments, the glass ribbon 103 may be stretched in the stretching direction 154 along the stretching plane 213. As shown, the stretching plane 213 may bisect the shaping wedge 110 through the root 145, but in some embodiments, the stretching plane 213 may extend in other orientations relative to the root 145.

[0036] Throughout this disclosure, the molten glass progression path 229 is defined as the path from the moment the molten glass 121 enters the glass molded body 140 until its strain point (i.e., when the viscosity of the molten glass 121 constituting the glass ribbon 103 is 10%). 14.5 It is defined as a path that continues until it cools to a temperature above Poise. The molten glass 121 may cool to its strain point as a glass ribbon 103 before reaching the separation path 151 (see Figure 1), but in further embodiments, the molten glass 121 may cool to its strain point after crossing the separation path 151 as a glass sheet 104. For example, as shown in Figures 2A-2B, the molten glass progression path 229 may be defined as the path along which the molten glass 121 progresses as it flows over the inclined convergent surface portions 207A, 207B, and / or the path along which the glass ribbon 103 progresses after being extended from the root portion 145 of the shaping wedge 110.

[0037] In addition, in some embodiments, the molten glass 121 flows into the trough 201 of the glass molded body 140, then flows simultaneously over the corresponding weirs 203A and 203B, and overflows from the trough 201 by flowing downward over the outer surfaces 205A and 205B of the corresponding weirs 203A and 203B. Each flow of molten glass 121 flows along the corresponding downward-sloping converging surface portions 207A and 207B of the molding wedge 110, extending from the root 145 of the glass molded body 140, where the flow converges and fuses into the glass ribbon 103. The glass ribbon 103 can then be extended from the root 145 of the stretching plane 213 along the stretching direction 154. In some embodiments, a glass separator 149 (see Figure 1) can then separate the glass sheet 104 (see Figure 1) from the glass ribbon 103 along the separation path 151. As illustrated, in some embodiments, the separation path 151 may extend along the width W of the glass ribbon 103 between a first outer edge 153 and a second outer edge 155. In addition, in some embodiments, the separation path 151 may extend perpendicular to the stretching direction 154 of the glass ribbon 103. Furthermore, in some embodiments, the stretching direction 154 may define the direction in which the glass ribbon 103 can be fusion drawn from the glass molded body 140. In some embodiments, the glass ribbon 103 may advance at a speed along the stretching direction 154 of about 1 millimeter per second or more, about 10 millimeters per second or more, about 50 millimeters per second or more, about 100 millimeters per second or more, or about 500 millimeters per second or more, for example, about 1 millimeter per second to about 500 millimeters per second, about 10 millimeters per second to about 500 millimeters per second, about 50 millimeters per second to about 500 millimeters per second, about 100 millimeters per second to about 500 millimeters per second, and all and partial ranges in between thereof.

[0038] As shown in Figure 2A, in some embodiments, the glass ribbon 103 is extended from the root portion 145, with surfaces 215A and 215B of the glass ribbon 103 facing each other, defining the average thickness T of the glass ribbon 103. In some embodiments, the average thickness T of the central portion 152 of the glass ribbon 103 (see Figure 1) may be about 5 mm or less, about 4 mm or less, about 3 mm or less, about 2 mm or less, about 1 mm or less, about 500 micrometers, about 300 micrometers or less, about 200 micrometers or less, or about 100 micrometers or less, but in further embodiments, other thicknesses may be provided. For example, in some embodiments, the average thickness T of the glass ribbon 103 may be in the range of about 50 micrometers to about 750 micrometers, about 100 micrometers to about 700 micrometers, about 200 micrometers to about 600 micrometers, about 300 micrometers to about 500 micrometers, about 50 micrometers to about 500 micrometers, about 50 micrometers to about 500 micrometers, about 50 micrometers to about 700 micrometers, about 50 micrometers to about 600 micrometers, about 50 micrometers to about 500 micrometers, about 50 micrometers to about 400 micrometers, about 50 micrometers to about 300 micrometers, about 50 micrometers to about 200 micrometers, or about 50 micrometers to about 100 micrometers, including all and partial ranges of thickness between them. In addition, the glass ribbon 103 may include, but is not limited to, a variety of compositions including soda-lime glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, alkali-containing glass, or alkali-free glass, none of which may or may not contain lithia.

[0039] In some embodiments, as shown in FIGS. 2A-2B, the glass manufacturing apparatus 100 may include a housing 218 having a housing wall 220 defined between an inner surface 222 and an outer surface 223 of the housing wall 220. In some embodiments, the interior 221 of the housing 218 may be at least partially defined by the inner surface 222 of the housing wall 220. In some embodiments, the housing wall 220 at least partially surrounds the glass forming body 140 such that the glass forming body 140 and a portion of the glass ribbon 103 are located within the interior 221 of the housing 218. As shown, the bulk material of the housing 218 located between the inner surface 222 and the outer surface 223 includes a first material, which may be a ceramic or other material having a low thermal conductivity. Without wishing to be bound by theory, materials with lower thermal conductivity tend to have better heat insulation properties than materials with higher thermal conductivity. In some embodiments, the first material is about 150 W m -1 K -1 Hereinafter, 50 W m -1 K -1 Hereinafter, about 30 W m -1 K -1 Hereinafter, about 0.01 W m -1 K -1 ~ about 150 W m -1 K -1 In the range of, about 0.01 W m -1 K -1 ~ about 50 W m -1 K -1 In the range of, or about 0.25 W m -1 K -1 ~ about 30 W m -1 K -1 Including a thermal conductivity in the range of, although in other embodiments other thermal conductivities may be acceptable.

[0040] Furthermore, the material of the housing 218 maintains its mechanical properties and dimensional stability at the operating temperature of the interior 221 of the housing 218 when molten glass 121 is present in the glass molded body 140. In some embodiments, the operating temperature may be approximately 500 degrees Celsius or higher, approximately 800 degrees Celsius or higher, approximately 1000 degrees Celsius or higher, approximately 1200 degrees Celsius or higher, approximately 1500 degrees Celsius or higher, approximately 1700 degrees Celsius or lower, or approximately 1600 degrees Celsius or lower. In some embodiments, the operating temperature may be in the range of approximately 500°C to 1700°C, approximately 800°C to 1700°C, approximately 1000°C to 1700°C, approximately 1200°C to 1700°C, approximately 500°C to 1600°C, approximately 800°C to 1600°C, approximately 1000°C to 1600°C, or approximately 1200°C to 1600°C. In some embodiments, the material of the housing 218 includes a melting temperature above 1600°C. If the material of the housing 218 includes an amorphous material, the operating temperature may be below the glass transition temperature of that material. In some embodiments, the first material is boron nitride (BN), silicon carbide (SiC), zirconium dioxide (ZrO2), SiAlON (i.e., a combination of alumina and silicon nitride, Si 12-m-n Al m+n O n N 16-n Si 6-n Al n O n N 8-n , or Si 2-n Al n O 1+n N 2-n The materials may have chemical formulas such as (where m, n, and any resulting subscripts are not all negative integers), aluminum nitride (AlN), graphite, alumina (Al2O3), silicon nitride (Si3N4), quartz glass, mullite (i.e., minerals containing a combination of aluminum oxide and silicon dioxide), or a combination of two or more of the aforementioned materials.

[0041] The glass manufacturing apparatus 100 may include one or more heating devices. For example, as illustrated in Figure 2A, the glass manufacturing apparatus 100 includes a first heating device 226A and a second heating device 226B, with the stretching plane 213 positioned between the first heating device 226A and the second heating device 226B. Although two heating devices 226A and 226B are shown, in other embodiments, a single heating device or three or more heating devices may be provided. Figure 2B is an enlarged view taken in field of view C of Figure 2A. Figure 2B illustrates and more fully describes the features of the first heating device 226A, and it will be understood that such a description may also apply to one or more other heating devices, such as the second heating device 226B.

[0042] In some embodiments, as shown in Figures 2A and 2B, passages 236A and 236B extend from the outer surface through the housing 218. For example, the first passage 236A extends through the housing 218 from the outer surface 223 of the housing wall 220 to the inner surface 222 of the housing wall 220. In some embodiments, as shown in Figures 2A and 2B, a first tube 235A containing a second material may be positioned within the first passage 236A, and a second tube 235B containing a second material may be positioned within the second passage 236B. However, passages 236A and 236B may be provided without any tubes 235A and 235B, and / or in other embodiments, may include a second material.

[0043] In some embodiments, tubes 235A and 235B include a second material which may be the same as the first material of the housing wall 220. In some embodiments, the second material may have a thermal conductivity that is approximately the same as or greater than that of the first material. In further embodiments, the second material may still have a melting temperature of about 1600 degrees Celsius or higher. For example, the first material may have a melting temperature of about 25 W m -1 K -1 The second material may have a thermal conductivity of less than 30 W m (e.g., quartz glass, fused silica, zirconium dioxide, mullite, SiAlON, graphite), and the second material may have a thermal conductivity of approximately 30 W m -1 K -1The above thermal conductivity may include (e.g., silicon nitride, boron nitride, alumina, silicon carbide, aluminum nitride). In some embodiments, the second material may function to homogenize the temperature in passages 236A, 236B compared to passages without the second material (e.g., without tubes 235A, 235B).

[0044] Each of the passages 236A and 236B may have a cross-section having a cross-sectional passage area. In some embodiments, the cross-sectional passage area may be about 2,000 square millimeters to about 12,000 square millimeters, about 4,000 square millimeters to about 10,000 square millimeters, or about 6,000 square millimeters to about 8,000 square millimeters. In some embodiments, the cross-sectional passage area may be minimized to reduce the amount of heat transferred through each of the passages 236A and 236B, but still accommodate optical fibers 231A and 231B that may extend into each of the passages 236A and 236B, tubes 235A and 235B if present, and laser beams 238A and 238B. However, while the optical fibers 231A and 231B are included in embodiments illustrated in Figures 2A and 2B, the system may be provided without any optical fibers 231A and 231B in other embodiments. If optical fibers are not included, the laser beam can be emitted from laser modules 233A and 233B so that the laser beam is directed toward the molten glass.

[0045] As shown in Figure 2A, the first heating device 226A may also comprise a first laser module 233A, and the second heating device 226B may also comprise a second laser module 233B. Laser modules 233A, 233B may include gas lasers, excimer lasers, dye lasers, or solid-state lasers. Exemplary embodiments of gas lasers include helium, neon, argon, krypton, xenon, helium-neon (HeNe), xenon-neon (XeNe), carbon dioxide (CO2), copper (Cu) vapor, gold (Au) vapor, cadmium (Cd) vapor, ammonia, hydrogen fluoride (HF), and deuterium fluoride (DF). Exemplary embodiments of excimer lasers include chlorine, fluorine, iodine, or nitrogen oxides (N2O) in an inert environment, including argon (Ar), krypton (Kr), xenon (Xe), or combinations thereof. Exemplary embodiments of dye lasers include those using organic dyes such as rhodamine, fluorescein, coumarin, stilbene, umbelliferone, tetracene, or malachite green dissolved in a liquid solvent. Exemplary embodiments of solid-state lasers include crystal lasers, fiber lasers, and laser diodes. Crystal-based lasers include host crystals doped with lanthanides or transition metals. Exemplary embodiments of host crystals include yttrium aluminum garnet (YAG), yttrium lithium fluoride (YLF), yttrium otoaluminate (YAL), yttrium scandium gallium garnet (YSSG), littrium aluminum hexafluoride (LiSAF), lithium calcium aluminum hexafluoride (LiCAF), zinc selenium (ZnSe), ruby, forsterite, and sapphire. Exemplary embodiments of the dopant include neodymium (Nd), titanium (Ti), chromium (Cr), iron (Fe), erbium (Er), holmium (Ho), thulium (Tm), ytterbium (Yb), dysprosium (Dy), cerium (Ce), gadolinium (Gd), samarium (Sm), and terbium (Tb).Exemplary embodiments of solid crystals include ruby, alexandrite, chromium fluoride, forsterite, lithium fluoride (LiF), sodium chloride (NaCl), potassium chloride (KCl), and rubidium chloride (RbCl). Laser diodes may include heterojunction diodes or PIN diodes having three or more materials in their respective p-type semiconductor layer, intrinsic semiconductor layer, and n-type semiconductor layer. Exemplary embodiments of laser diodes include AlGaInP, AlGaAs, InGaN, InGaAs, InGaAsP, InGaAsN, InGaAsNSb, GaInP, GaAlAs, GaInAsSb, and lead (Pb) salts. Some laser diodes may represent the exemplary embodiments due to their size, adjustable power output, and ability to operate at room temperature, which may range from about 20 to about 25 degrees Celsius. As described below, fiber lasers comprise optical fibers further comprising a cladding having one of the materials listed above for crystalline lasers or laser diodes.

[0046] Laser modules 233A and 233B are configured to emit laser beams 238A and 238B (see Figure 2B), each containing a specific wavelength. Laser modules 233A and 233B may operate to reduce the wavelength of laser beams 238A and 238B by half (doubling the frequency), by two-thirds (tripling the frequency), by three-quarters (quadruple the frequency), or otherwise modify the wavelength of the laser beams 238A and 238B generated by the laser modules 233A and 233B. In some embodiments, the wavelength of laser beams 238A and 238B may range from approximately 400 nanometers to approximately 11,000 nanometers. In some embodiments, the wavelengths of the laser beams 238A and 238B may be approximately 760 nanometers or more, approximately 900 nanometers or more, approximately 980 nanometers or more, approximately 5,000 nanometers or less, approximately 4,000 nanometers or less, approximately 3,000 nanometers or less, approximately 1,700 nanometers or less, approximately 1,660 nanometers or less, approximately 1,570 nanometers or less, approximately 1,330 nanometers or less, or approximately 1,100 nanometers or less.In some embodiments, the wavelengths of laser beams 238A and 238B are approximately 760 nanometers to 5,000 nanometers, approximately 760 nanometers to 4,000 nanometers, approximately 760 nanometers to 3,000 nanometers, approximately 760 nanometers to 1,700 nanometers, approximately 760 nanometers to 1,660 nanometers, approximately 760 nanometers to 1,570 nanometers, approximately 760 nanometers to 1,330 nanometers, approximately 760 nanometers to 1,100 nanometers, approximately 900 nanometers to 5,000 nanometers, approximately 900 nanometers to 4,000 nanometers, approximately 900 nanometers to 3,000 nanometers, and approximately 900 nanometers to 1,100 nanometers. It may be in the range of 700 nanometers, approximately 900 nanometers to approximately 1,660 nanometers, approximately 900 nanometers to approximately 1,570 nanometers, approximately 900 nanometers to approximately 1,330 nanometers, approximately 900 nanometers to approximately 1,100 nanometers, approximately 980 nanometers to approximately 5,000 nanometers, approximately 980 nanometers to approximately 4,000 nanometers, approximately 980 nanometers to approximately 3,000 nanometers, approximately 980 nanometers to approximately 1,700 nanometers, approximately 980 nanometers to approximately 1,660 nanometers, approximately 980 nanometers to approximately 1,570 nanometers, approximately 980 nanometers to approximately 1,330 nanometers, or approximately 980 nanometers to approximately 1,100 nanometers. Exemplary embodiments of laser diodes capable of generating laser beams 238A, 238B having wavelengths within the aforementioned range include AlGaAs, InGaAsP, and InGaAsN laser diodes. Exemplary embodiments of laser modules 233A, 233B (excluding diode lasers) capable of generating laser beams 238A, 238B having wavelengths within the aforementioned range include He-Ne gas lasers, Ar gas lasers, iodine excimer lasers, Nd-doped YAG solid-state lasers, Nd-doped YLF solid-state lasers, Nd-doped YAP solid-state lasers, Ti-doped sapphire solid-state lasers, Cr-doped LiSAF solid-state lasers, chromium fluoride solid-state lasers, forsterite solid-state lasers, LiF solid-state lasers, and NaCl solid-state lasers.Exemplary embodiments of laser modules 233A, 233B capable of generating laser beams 238A, 238B having wavelengths within the aforementioned ranges when the frequency is doubled include, when the frequency is doubled, XeNe gas lasers, HF gas lasers, Ho-doped YAG solid-state lasers, Er-doped YAG solid-state lasers, Tm-doped YAG solid-state lasers, KCl solid-state lasers, RbCl solid-state lasers, and AlGaIn laser diodes. In some embodiments, laser modules 233A, 233B may include a carbon dioxide (CO2) laser, and laser modules 233A, 233B may operate between wavelengths of about 8,000 nanometers to about 12,000 nanometers, about 8,500 nanometers to about 11,500 nanometers, and about 9,000 nanometers to about 11,000 nanometers. In some embodiments, laser modules 233A and 233B may be equipped with a carbon monoxide (CO) laser, and may operate at wavelengths of about 2,500 nanometers to about 7,500 nanometers, about 4,000 nanometers to about 6,000 nanometers, or about 5,000 nanometers. Exemplary embodiments of laser modules 233A and 233B that can generate laser beams 238A and 238B having wavelengths within the aforementioned range include, at three times the frequency, a HeNe gas laser, a DF gas laser, and a Pb salt laser diode.

[0047] The laser beams 238A and 238B may be configured to contact the surfaces of the molten glass 121. For example, in Figure 2B, the laser beam 238A is configured to contact surface 215A' of the molten glass 121, and the laser beam 238B is configured to contact surface 215B' of the molten glass 121. Surfaces 215A' and 215B' are each above the root 145. However, in other embodiments, the laser beam 238A may contact surface 215A of the molten glass 121, and the laser beam 238B may contact surface 215B of the molten glass 121, with surfaces 215A and 215B below the root 145 of the glass molded body 140.

[0048] As shown in Figure 2B, the heating devices 226A, 226B may also optionally include optical fibers 231A, 231B. However, in some embodiments, these optical fibers 231A, 231B are not included. The optical fibers 231A, 231B may each include a first end 239A, 239B (see Figure 2A) and a second end 237A, 237B (see Figure 2A) opposite the first end 239A, 239B. Throughout this disclosure, the length of an optical fiber is defined as the distance between a first point on the first end of the optical fiber and a second point on the second end of the optical fiber, when the optical fiber is straightened so that the optical fiber is aligned with an elongated axis and the first point and the second point are as far apart as possible. In some embodiments, the lengths of optical fibers 231A and 231B may be in the range of approximately 100 millimeters or more, approximately 1 meter or more, approximately 2 meters or more, approximately 5 meters or more, approximately 2,000 meters or less, approximately 50 meters or less, approximately 30 meters or less, approximately 20 meters or less, or approximately 10 meters or less. In some embodiments, the lengths of optical fibers 231A and 231B may be in the range of approximately 100 millimeters to approximately 2,000 meters, approximately 100 millimeters to approximately 50 meters, approximately 100 millimeters to approximately 30 meters, approximately 100 millimeters to approximately 20 meters, approximately 100 millimeters to approximately 10 meters, approximately 1 meter to approximately 2,000 meters, approximately 1 meter to approximately 50 meters, approximately 1 meter to approximately 30 meters, approximately 1 meter to approximately 20 meters, approximately 1 meter to approximately 10 meters, approximately 2 meters to approximately 30 meters, approximately 2 meters to approximately 20 meters, approximately 2 meters to approximately 10 meters, or approximately 5 meters to approximately 10 meters.

[0049] Optical fibers 231A and 231B may comprise a core containing an optical material. Throughout this disclosure, the width of the optical fiber core is defined as the distance between a first point at the second end of the optical fiber and a second point at the second end of the optical fiber, wherein the first and second points contain the same material as the center of the second end of the fiber, and the first and second points are as far apart as possible. For example, the width of the optical fiber core may be equal to the diameter if the core at the second end of the optical fiber is circular. If the core at the second end of the optical fiber is elliptical, the width is equal to twice the semi-major axis. In some embodiments, the width of the core of optical fibers 231A and 231B may be about 1 micrometer or more, about 5 micrometers or more, about 9 micrometers or more, about 50 micrometers or more, about 62.5 micrometers or more, about 550 micrometers or less, about 490 micrometers or less, about 400 micrometers or less, about 360 micrometers or less, about 255 micrometers or less, or about 145 micrometers or less.In some embodiments, the core widths of optical fibers 231A and 231B are approximately 1 micrometer to 550 micrometers, approximately 1 micrometer to 490 micrometers, approximately 1 micrometer to 400 micrometers, approximately 1 micrometer to 360 micrometers, approximately 1 micrometer to 255 micrometers, approximately 1 micrometer to 145 micrometers, approximately 5 micrometers to 550 micrometers, approximately 5 micrometers to 490 micrometers, approximately 5 micrometers to 255 micrometers, approximately 9 micrometers to 550 micrometers, approximately 9 micrometers to 490 micrometers, approximately 9 micrometers to 400 micrometers, and approximately 9 micrometers to 360 micrometers. The ranges may be approximately 9 micrometers to 250 micrometers, 9 micrometers to 144 micrometers, 50 micrometers to 550 micrometers, 50 micrometers to 490 micrometers, 50 micrometers to 400 micrometers, 50 micrometers to 144 micrometers, 62.5 micrometers to 550 micrometers, 62.5 micrometers to 550 micrometers, 62.5 micrometers to 490 micrometers, 62.5 micrometers to 400 micrometers, 62.5 micrometers to 360 micrometers, 62.5 micrometers to 255 micrometers, and 62.5 micrometers to 150 micrometers.

[0050] In some embodiments, the optical material in the core of the optical fibers 231A, 231B includes sapphire, fused silica, quartz, or a combination thereof. In further embodiments, the optical material may be doped with an optical amplification factor such as erbium (Er), ytterbium (Yb), neodymium (Nd), or germanium dioxide (GeO2). In some embodiments, the optical fibers 231A, 231B may have a cladding surrounding the core. In further embodiments, the cladding may include a refractive index lower than that of the core. In yet further embodiments, the cladding may include fused silica, quartz, sapphire, or a gas, such as air, nitrogen, or argon. In yet further embodiments, the cladding may include any of the materials listed above for laser diodes or crystalline lasers. Doping, cladding, or a combination of the two may be desirable to modify the amplitude of the laser beams 238A, 238B transmitted by the optical fibers 231A, 231B (for example, the optical fiber may be a fiber laser). In some embodiments, the cores of optical fibers 231A, 231B may include a circular cross-section. Optical fibers having a core with a circular cross-section can provide a smooth (e.g., homogeneous and symmetrical) intensity profile to laser beams 238A, 238B exiting the second ends 237A, 237B of optical fibers 231A, 231B. In some embodiments, the first ends 239A, 239B of optical fibers 231A, 231B may include a circular cross-section, and the second ends 237A, 237B of optical fibers 231A, 231B may include a circular cross-section. In some embodiments, providing a circular cross-section in optical fibers 231A, 231B can be used in conjunction with passages 236A, 236B and / or tubes 235A, 235B having a circular cross-section.

[0051] Looking at Figure 2B, the tubes 235A and 235B may include a thickness T1 measured between the outer dimensions of the tubes 235A and 235B and the inner dimensions of the tubes 235A and 235B. In some embodiments, the thickness T1 of the tubes 235A and 235B may be about 100 nanometers or more, about 1 micrometer or more, about 10 micrometers or more, about 50 micrometers or more, about 2,000 micrometers or less, about 990 micrometers or less, about 490 micrometers or less, about 400 micrometers or less, about 300 micrometers or less, about 200 micrometers or less, or about 100 micrometers or less.In some embodiments, the thickness T1 of tubes 235A and 235B is approximately 100 nanometers to approximately 2,000 micrometers, approximately 1 micrometer to approximately 2,000 micrometers, approximately 10 micrometers to approximately 2,000 micrometers, approximately 50 micrometers to approximately 2,000 micrometers, approximately 100 nanometers to approximately 990 micrometers, approximately 1 micrometer to approximately 990 micrometers, approximately 10 micrometers to approximately 990 micrometers, approximately 50 micrometers to approximately 990 micrometers, approximately 100 nanometers to approximately 490 micrometers, approximately 1 micrometer to approximately 490 micrometers, approximately 10 micrometers to approximately 490 micrometers, approximately 50 micrometers to approximately 490 micrometers, approximately 100 nanometers to approximately 400 micrometers, and approximately 1 micrometer. The range may be approximately 400 micrometers, approximately 10 micrometers to approximately 400 micrometers, approximately 50 micrometers to approximately 400 micrometers, approximately 100 nanometers to approximately 300 micrometers, approximately 1 micrometer to approximately 300 micrometers, approximately 10 micrometers to approximately 300 micrometers, approximately 50 micrometers to approximately 300 micrometers, approximately 100 nanometers to approximately 200 micrometers, approximately 1 micrometer to approximately 200 micrometers, approximately 10 micrometers to approximately 200 micrometers, approximately 50 micrometers to approximately 200 micrometers, approximately 100 nanometers to approximately 100 micrometers, approximately 1 micrometer to approximately 100 micrometers, approximately 10 micrometers to approximately 100 micrometers, or approximately 50 micrometers to approximately 100 micrometers.

[0052] In some embodiments, as shown in Figures 2A to 2B, the optical fibers 231A and 231B may extend into passages 236A and 236B within the housing 218. In further embodiments, the optical fibers 231A and 231B may extend entirely through the housing 218 into passages 236A and 236B. In yet another embodiment, the optical fibers 231A and 231B may extend entirely through tubes 235A and 235B within passages 236A and 236B. In yet another embodiment, as shown in Figures 2A to 2B, the optical fibers 231A and 231B may extend partially through tubes 235A and 235B within passages 236A and 236B. In other embodiments, though not shown, optical fibers 231A and 231B may extend partially through tubes 235A and 235B in portions of the tubes 235A and 235B outside of passages 236A and 236B. In other embodiments, though not shown, optical fibers 231A and 231B may not extend at all into passages 236A and 236B within the housing 218, and laser beams 238A and 238B may be transmitted through passages 236A and 236B, respectively, within the housing 218.

[0053] In some embodiments, as illustrated in Figure 2B, tubes 235A, 235B may be held in place by faceplates. For example, faceplate 243 may hold tube 235A in place. In addition to or instead of this, faceplate 243 may act to cap passages 236A, 236B to minimize heat loss through passages 236A, 236B. Faceplate 243 may be connected to the outer surface 223 of the housing 218 by fasteners 241 or other mounting devices. In some embodiments, fasteners 241 may comprise rivets, nails, screws, bolts, snaps, latches, buckles, hook-and-loop fasteners, latches, cable ties, straps, pins, or pegs. In addition, faceplates such as faceplate 243 may act to minimize heat loss from any space between the inner surfaces of tubes 235A, 235B and the surfaces of passages 236A, 236B within the housing 218.

[0054] The optical fibers 231A and 231B may be positioned such that their second ends 237A and 237B face the molten glass propagation path 229. In some embodiments, as shown in Figures 2A and 2B, the optical fibers 231A and 231B extend partially through the passages 236A and 236B. In some embodiments, not shown, the optical fibers 231A and 231B face the passages 236A and 236B but do not extend within them. In some embodiments, not shown, the optical fibers 231A and 231B may extend entirely through the passages 236A and 236B and protrude into the interior 221 beyond the inner surface 222 of the housing 218. In some embodiments, the optical element may be placed between the second ends 237A and 237B of the optical fibers 231A and 231B and the molten glass propagation path 229. In some embodiments, the distance between the second ends 237A, 237B of the optical fibers 231A, 231B and the optical element can be fixed by attaching the optical element to a transparent material (e.g., a material suitable for use as the core of the optical fibers 231A, 231B) and the second ends 237A, 237B of the optical fibers 231A, 231B, where the refractive index of the transparent material is approximately the same as or less than that of the core of the optical fibers 231A, 231B. In other embodiments, the distance between the second ends 237A, 237B of the optical fibers 231A, 231B and the optical element can be variable. For example, the optical element can be attached to the end of the passage 236A, 236B closest to the interior 221 of the housing 218, while the optical fibers 231A, 231B can move independently within the passage 236A, 236B. An exemplary optical element may be a collimating lens that acts to control the divergence of laser beams 238A, 238B emanating from the second ends 237A, 237B of the optical fibers 231A, 231B. In some embodiments, the collimating lens may be spherical, elliptical, or cylindrical. In some embodiments, two or more lenses may be present as part of the optical element.

[0055] The power density and / or size of the laser beams 238A, 238B that strike a portion of the molten glass 121 on the molten glass propagation path 229 can be achieved in a wide range of ways, such as by adjusting the position of the second ends 237A, 237B of the optical fibers 231A, 231B, the type of optical element, or the position of the optical element. Throughout this disclosure, the width of the laser beams 238A, 238B that strike a portion of the molten glass 121 is about 13.5% (i.e., 1 / e) of the maximum intensity of the laser beams 238A, 238B at their position on the molten glass 121. 2The maximum width of the laser beams 238A and 238B is defined as the distance in the direction across the molten glass propagation path 229 between a first point on the molten glass 121 struck by a laser beam 238A or 238B having intensity, and a second point on the molten glass 121 struck by a laser beam 238A or 238B, where the first point and the second point are as far apart as possible in the direction across the molten glass propagation path 229. The beam profiles of the laser beams 238A and 238B may be Gaussian beam profiles, but non-Gaussian beam profiles (e.g., top-hat shaped beams) are as preferred as non-circular beams (e.g., elliptical beams). In some embodiments, the maximum width of the laser beams 238A and 238B may be about 100 micrometers or more, about 200 micrometers or more, about 500 micrometers or more, about 1 millimeter or more, about 2 millimeters or more, about 5 millimeters or more, about 10 millimeters or more, about 30 millimeters or less, about 20 millimeters or less, or about 15 millimeters or less. The molten glass propagation path 229 is perpendicular to the stretching direction 154 and may be parallel to the stretching plane 213. In some embodiments, the maximum width of the laser beams 238A and 238B can be in the range of approximately 100 micrometers to approximately 30 millimeters, approximately 100 micrometers to approximately 20 millimeters, approximately 100 micrometers to approximately 15 millimeters, approximately 200 micrometers to approximately 30 millimeters, approximately 200 micrometers to approximately 20 millimeters, approximately 200 micrometers to approximately 15 millimeters, approximately 500 micrometers to approximately 30 millimeters, approximately 500 micrometers to approximately 20 millimeters, approximately 500 micrometers to approximately 15 millimeters, approximately 1 millimeter to approximately 30 millimeters, approximately 1 millimeter to approximately 20 millimeters, approximately 1 millimeter to approximately 15 millimeters, approximately 2 millimeters to approximately 30 millimeters, approximately 2 millimeters to approximately 20 millimeters, approximately 2 millimeters to approximately 15 millimeters, approximately 5 millimeters to approximately 30 millimeters, approximately 5 millimeters to approximately 20 millimeters, approximately 5 millimeters to approximately 15 millimeters, approximately 10 millimeters to approximately 30 millimeters, approximately 10 millimeters to approximately 20 millimeters, or approximately 15 millimeters to approximately 20 millimeters.Throughout this disclosure, the area of ​​the molten glass 121 struck by the laser beams 238A and 238B is approximately 13.5% (i.e., 1 / e) of the maximum intensity of the laser beams 238A and 238B. 2 It is defined as a portion of molten glass 121 that is struck by laser beams 238A and 238B at an intensity of ), and its area is measured at the surface of molten glass 121 closest to the second ends 237A and 237B of the optical fibers 231A and 231B.

[0056] Throughout this disclosure, the power of the laser beams 238A and 238B is the average power of the laser beams 238A and 238B transmitted from the second ends 237A and 237B of the optical fibers 231A and 231B, measured using a thermopile. In some embodiments, the power of the laser beams 238A and 238B can be controlled by controlling the optical elements between the laser modules 233A and 233B and the second ends 237A and 237B of the optical fibers 231A and 231B. In some embodiments, the power of the laser beams can be controlled by adjusting the laser parameters (e.g., current or voltage, optical pump conditions). Throughout this disclosure, the power density of each laser beam 238A and 238B is the power of each laser beam 238A and 238B divided by the area of ​​the molten glass 121 impacted by the laser beams 238A and 238B, as defined above. In some embodiments, the power density of each of the laser beams 238A and 238B is approximately 1,500 watts / cm². 2 (W / cm 2 ), approx. 1W / cm 2 Above, about 2W / cm 2 Above, about 5W / cm 2 Above, about 10W / cm 2 Above, about 20W / cm 2 Approximately 2,000W / cm 2 Below, approximately 1,000W / cm 2 Below, approximately 500W / cm 2 Below, approximately 200W / cm 2 Below, about 100W / cm 2 The following, or approximately 50 W / cm² 2May be as follows. In some embodiments, the power density of each of the laser beams 238A, 238B is about 1 W / cm 2 to about 2,000 W / cm 2 、about 1 W / cm 2 to about 1,000 W / cm 2 、about 1 W / cm 2 to about 500 W / cm 2 、about 1 W / cm 2 to about 200 W / cm 2 、about 1 W / cm 2 to about 100 W / cm 2 、about 1 W / cm 2 to about 50 W / cm 2 、about 2 W / cm 2 to about 2,000 W / cm 2 、about 2 W / cm 2 to about 1,000 W / cm 2 、about 2 W / cm 2 to about 500 W / cm 2 、about 2 W / cm 2 to about 200 W / cm 2 、about 2 W / cm 2 to about 100 W / cm 2 、about 2 W / cm 2~約 50 W / cm 2 、about 5 W / cm 2 to about 2,000 W / cm 2 、about 5 W / cm 2 to about 1,000 W / cm 2 、about 5 W / cm 2 to about 500 W / cm 2 、about 5 W / cm 2 to about 200 W / cm 2 、about 5 W / cm 2 to about 100 W / cm 2 、about 5 W / cm 2 to about 50 W / cm 2 、about 10 W / cm 2 to about 2,000 W / cm 2 、about 10 W / cm 2 to about 1,000 W / cm 2 、about 10 W / cm 2 to about 500 W / cm 2 、about 10 W / cm 2 to about 200 W / cm 2 、about 10 W / cm2 ~ about 100 W / cm 2 、 about 10 W / cm 2 ~ about 50 W / cm 2 、 about 20 W / cm 2 ~ about 2,000 W / cm 2 、 about 20 W / cm 2 ~ about 1,000 W / cm 2 、 about 20 W / cm 2 ~ about 500 W / cm 2 、 about 20 W / cm 2 ~ about 200 W / cm 2 、 about 20 W / cm 2 ~ about 100 W / cm 2 、 or about 20 W / cm 2 ~ about 50 W / cm 2 can be in the range of.

[0057] Throughout this disclosure, a target location is defined as a location to be struck by a laser beam. Referring to Figure 2B, first target locations 232A, 232A' on the molten glass 121 may be defined as locations where the laser beam 238A, 238B strikes a portion of the molten glass 121 as it travels along the molten glass progression path 229. In some embodiments, as shown in Figures 2A-2B, the first target locations 232A, 232A' on the molten glass 121 may be on the root portion 145 of the glass molded body 140. In further embodiments, the laser beam 238A, 238B may strike a portion of the inclined convergent surface portion 207A of the glass molded body 140 at second target locations 232B, 232B' on the surface of the glass molded body 140. In some embodiments, the molten glass 121 typically moves slower than the molten glass 121 below the root 145, meaning that when the first target positions 232A, 232A' are above the root 145, a portion of the molten glass 121 can be struck by the laser beams 238A, 238B for a longer period than when the first target positions 232A, 232A' are below the root 145. Therefore, it may be desirable for the first target positions 232A, 232A' to be above the root 145 of the glass molded body 140. Furthermore, to compensate for thickness deviations of portions of the molten glass 121 that are specific to the corresponding sides of the glass molded body 140, it may be desirable for the first target positions 232A, 232A' to be above the root 145 of the glass molded body 140. For example, one of the weirs 203A, 203B of the glass molded body 140 may contain an imperfection that causes the molten glass to produce a “streak” thicker than desired, and heating the molten glass 121 on the outer surfaces 205A, 205B and / or the corresponding sides of the glass molded body 140 on the inclined converging surface portions 207A, 207B may improve this “streak” before the molten glass 121 converges and stretches at the root 145. Furthermore, in some embodiments, it may be beneficial to provide first target positions 232A, 232A' above the root 145 to allow the energy passing through the molten glass to be captured by the molding vessel at second target positions 232B, 232B'.Therefore, the molding vessel may be further heated at the second target positions 232B, 232B', and / or the laser beam may be reflected from the molding vessel and further heat the portion of the molten glass that progresses beyond the second target positions 232B, 232B' while being directly heated by the laser beams 238A, 238B at the first target positions 232A, 232A'. As a result, heating efficiency for heating the desired position of the molten glass may, in some embodiments, be achieved by directly heating the molten glass 121 with the laser beams 238A, 238B at the first target positions 232A, 232A', while simultaneously further indirectly heating the molten glass 121 with the portion of the molding vessel heated by the laser beams 238A, 238B, and / or by reflecting the laser beam from the molding vessel at the second target positions 232B, 232B'. In other embodiments, the laser beams 238A and 238B may strike a portion of the molten glass 121 at a target position on the molten glass 121 as the molten glass 121 moves along the molten glass propagation path 229 below the root 145 of the glass molded body 140. When the laser beams 238A and 238B strike a portion of the molten glass 121 at a target position below the root 145, the spatial resolution may be improved compared to other embodiments in which the laser beams 238A and 238B strike a target position above the root 145. In addition, when the target position is below the root 145, this may result in a more uniform change in the thickness on both sides of the molten glass 121. Embodiments in which the target position of the laser beams 238A and 238B is set above the root 145 may result in a reduction in resolution due to heat conduction in the glass molded body 140 compared to embodiments in which the target position of the laser beams 238A and 238B is below the root 145.

[0058] In some embodiments, as shown in Figure 2B, the laser beam 238A of the first heating device 226A may be parallel to the laser beam 238B of the second heating device 226B. In other embodiments, not shown, the laser beam 238A of the first heating device 226A may not be parallel to the laser beam 238B of the second heating device 226B. In some embodiments, as shown in Figure 2B, the laser beam 238A of the first heating device 226A and the laser beam 238B of the second heating device 226B may collide with portions of the molten glass 121 that may be at the same height position on the stretching plane 213. In other embodiments, the laser beam 238A of the first heating device 226A and the laser beam 238B of the second heating device 226B may collide with portions of the molten glass 121 that may be at different height positions on the stretching plane 213. It is understood that any of the arrangements of the laser beam 238A of the first heating device 226A may be parallel to the laser beam 238B of the second heating device 226B, and that this can be used in combination with embodiments in which the first target positions 232A, 232A' are above the root 145 of the glass molded body 140 and the target position is below the root of the molding vessel, or that a hybrid of these embodiments may be used in which the laser beam 238A of the first heating device 226A collides with the first target position 232A above the root 145 of the glass molded body 140 and the laser beam 238B of the second heating device 226B collides with the target position below the root 145 of the molding vessel.

[0059] Throughout this disclosure, the angle of incidence is defined as the angle formed by the intersection of a plane defined by the plane of the molten glass 121 at the first target positions 232A, 232A' closest to the second ends 237A, 237B of the optical fibers 231A, 231B and a line passing through the centers of the second ends 237A, 237B of the optical fibers and the centers of the first target positions 232A, 232A' of the molten glass 121 on the molten glass propagation path 229. In some embodiments, the angle of incidence may be about 70 degrees or more, about 80 degrees or more, about 85 degrees or more, about 88 degrees or more, about 90 degrees, about 110 degrees or less, 100 degrees or less, about 95 degrees or less, about 92 degrees or less, or about 90 degrees. In some embodiments, the angle of incidence may be in the range of about 70 degrees to about 110 degrees, about 80 degrees to about 100 degrees, about 85 degrees to about 95 degrees, or about 88 degrees to about 92 degrees. Throughout this disclosure, the angle of incidence may be considered “nearly vertical” if it is in the range of about 80 to about 100 degrees, about 85 to about 95 degrees, about 88 to about 92 degrees, or about 90 degrees. In some embodiments, each of the passages 236A, 236B may be inclined such that the angle of incidence is vertical when the first target positions 232A, 232A' are above the root 145 of the glass molded body 140.

[0060] The molten glass 121 may contain a certain absorption depth at the wavelengths of the laser beams 238A and 238B. Throughout this disclosure, the absorption depth of a material is defined as the thickness of the material to which the intensity (e.g., power, power density) of the laser beams 238A and 238B decreases to 36.8% (i.e., 1 / e) of the initial intensity of the laser beams 238A and 238B. While we do not wish to be bound by theory, it is possible to estimate the absorption depth using the Beer-Lambert law, which predicts that the intensity decreases exponentially when the material thickness is divided by the absorption depth. For some materials, the absorption depth may vary with temperature. Unless otherwise specified, the absorption depth was measured at approximately 1000 degrees Celsius. In some embodiments, the molten glass 121 may have absorption depths of about 200 micrometers or less, about 150 micrometers or less, about 125 micrometers or less, about 100 micrometers or less, about 75 micrometers or less, about 50 micrometers or less, or about 25 micrometers or less at the wavelengths of the laser beams 238A and 238B. It may be desirable that the absorption depth be greater than the thickness of the molten glass so that the entire portion of the molten glass that is struck by the laser beams 238A and 238B is heated by the laser beams 238A and 238B.

[0061] As described herein, a glass manufacturing apparatus 100 comprising laser modules 233A, 233B and optical fibers 231A, 231B may be used in a method for manufacturing glass. Firstly, molten glass 121 may flow from the glass molded body 140 along the molten glass progression path 229. Next, laser beams 238A, 238B may be transmitted from the laser modules 233A, 233B to the first ends 239A, 239B of the optical fibers 231A, 231B. The laser beams 238A, 238B may propagate along the optical fibers 231A, 231B from the first ends 239A, 239B to the second ends 237A, 237B of the optical fibers 231A, 231B. Furthermore, laser beams 238A, 238B can be transmitted from the second ends 237A, 237B of the optical fibers 231A, 231B toward the molten glass propagation path 229. The laser beams 238A, 238B can then collide with first target positions 232A, 232A' while the molten glass 121 is flowing along the molten glass propagation path 229. The laser beams 238A, 238B can heat portions of the molten glass 121 at the first target positions 232A, 232A'. The laser beams 238A, 238B can also reduce the viscosity of portions of the molten glass 121 at the first target positions 232A, 232A'. In some embodiments, the first target positions 232A, 232A' can be selected by determining portions of the molten glass 121 that include a thickness having a deviation from a predetermined thickness when the deviation is greater than a predetermined threshold. Therefore, heating the first target positions 232A and 232A' can be achieved by colliding laser beams 238A and 238B onto the first target positions 232A and 232A' to reduce the viscosity of a portion of the molten glass 121 at the target positions, which can reduce the deviation of the thickness of that portion of the molten glass 121 from a predetermined thickness.

[0062] In some embodiments, the target position of the molten glass 121 may be below the root 145 of the glass molded body 140. As a result, a portion of the molten glass 121 may include a glass ribbon 103 (see Figures 1, 2A-2B) at the target position, and the laser beams 238A, 238B may heat the portion of the molten glass 121 including the glass ribbon 103 (see Figures 1, 2A-2B). In other embodiments, as illustrated in Figure 2B, the first target positions 232A, 232A' may be above the root 145 of the glass molded body 140. In further embodiments, the laser beams 238A, 238B may heat a surface portion of the glass molded body 140 (e.g., a portion of the inclined convergent surface portion 207A, 207B) at a second target position 232B, 232B' in addition to the first target positions 232A, 232A' of the molten glass 121. In further embodiments, portions of the laser beams 238A, 238B may be reflected from a surface portion of the glass molded body 140 (e.g., portions of the inclined convergent surface portions 207A, 207B) at second target positions 232B, 232B' to reheat portions of the molten glass 121 at first target positions 232A, 232A'. However, in some embodiments, such as when a carbon dioxide laser is used to generate the laser beam, the absorption depth may be shallow, and a minimum amount of laser power may reach the glass molded body 140. In addition, in some embodiments, the glass molded body 140 may absorb the laser power and convert it into heat, which results in further heat transfer to the molten glass 121 as portions adjacent to the inclined convergent surface portions 207A, 207B.

[0063] In some embodiments, optical elements may be used to redirect a laser beam from a laser module. Figure 2C is a schematic diagram illustrating an exemplary optical element used to redirect a laser beam from a laser module toward a surface of molten glass. The optical element in Figure 2C is a reflector 248 included as part of a control device 210. However, the optical element may take other forms, such as a lens or a refractive element. The reflector 248 includes one or more reflective surfaces 214. The laser module 233C is configured to generate a laser beam 213A, which is directed toward the reflector 248. The reflector 248 is configured to reflect the laser beam 213A generated and emitted by the laser module 233C toward a portion of the surface 215A of the molten glass 121. Thus, the reflector 248 can function as a beam steering and / or scanning device. In Figure 2C, the laser beam 213A is illustrated as advancing as a reflected laser beam 217 onto a plurality of pre-selected portions of the surface 215A of the molten glass 121, as a result of incremental adjustments to the orientation of the reflective surface 214 with respect to the reception of the laser beam 213A by the reflective surface 214 and the position of the surface 215A of the molten glass 121. However, it is noted herein that any thickness variations that may occur with respect to the glass substrate can be localized so that they exist in localized regions where the thickness variations are very small. Since the laser beam spot striking the glass substrate is also very small, localized thickness variations can be dealt with without affecting directly adjacent portions of the glass substrate. Therefore, the laser beam can provide localized heating with high spatial resolution.

[0064] The reflector 248 in the embodiment illustrated in Figure 2C also includes an adjustment mechanism 252 configured to adjust the orientation of the reflecting surface 214 of the reflector 248 and the position of the surface 215A of the molten glass 121 in a viscous state for receiving the laser beam 213A. Thereafter, the laser beam 213A can be reflected as a laser beam 217 reflected from the reflecting surface 214 to at least one pre-selected portion of the glass substrate. In one example, the adjustment mechanism 252 may include a galvanometer operably associated with the reflecting surface 214 so that the reflecting surface 214 can be rotated by the galvanometer along an axis in relation to the surface 215A. For example, the reflecting surface 214 may be driven by a galvanometer motor and mounted on a rotating shaft 250 that rotates around axis A1, as indicated by the double arrow 219.

[0065] As illustrated in the embodiment of Figure 2C, the reflector 248 is positioned relative to the molten glass 121 such that the laser beam 213A can be directed from the reflective surface 214 of the reflector 248 to at least one pre-selected portion of the surface 215A of the molten glass 121 in a viscous state before the thickness of at least one pre-selected portion of the glass ribbon is fixed. In the embodiment of Figure 2C, the reflected laser beam 217 is directed to the molten glass 121 below the root 145 (see Figure 2A). In some embodiments, the reflected laser beam 217 may be continuously scanned across the width W of the molten glass 121, and the laser beam 217 may travel across the glass at a constant linear velocity. As the reflected laser beam 217 is scanned across the width W, the power level may vary at different locations based on the power profile utilized by the laser module 233C. The reflected laser beam 217 can be scanned by rotating the reflective surface 214, or it can be scanned without rotating the reflective surface 214 by shifting the direction of the laser beam 213A relative to the reflective surface 214. When scanning is achieved by rotating the reflective surface 214, the change in the amount of laser power applied can be synchronized with the movement of the reflective surface 214. An increased amount of laser power can be used for positions on the molten glass 121 when it is too thick, and a reduced amount of laser power can be used for positions on the molten glass 121 when it is thinner. Thus, the reflected laser beam 217 is directed to positions where separate flows of molten glass 121 flowing along the inclined converging surface portions 207A, 207B (see Figure 2A) converge to form a glass ribbon in a viscous state. During scanning, the reflected laser beam 217 is directed to positions where the thickness of the glass ribbon is still not fixed. However, the reflected laser beam 217 does not need to be directed towards the glass ribbon below the root 145, but may be directed towards a position above the root.The laser beam can be directed to contact a contact area on the molten glass 121, and the “influenced area” is defined as the area affected by the laser beam, which is potentially larger than the contact area. While the laser beam can contact a specific contact area, the surrounding area around the contact area can be heated to an increased temperature because the overall influenced area is larger than the contact area. By increasing the temperature of the pre-selected portion of the glass substrate and reducing its viscosity at a location where the pre-selected portion of the glass substrate is in a viscous state and its thickness is not fixed, the pre-selected portion of the glass substrate tends to flow such that its thickness becomes desirable at the pre-selected portion of the glass substrate, for example, under the influence of thermomechanical and other forces present at the pre-selected portion of the glass substrate.

[0066] Various mounting approaches can be used for laser modules, and Figures 3–8 illustrate some exemplary mounting approaches. The mounting angle of the laser module can be adjusted to different inclination angles with respect to the direction perpendicular to the molten glass surface. As used herein, “inclination angle” is the difference between the angle perpendicular to the surface of the molten glass and the angle parallel to the centerline of the scanning field of the laser module. Increasing the inclination angle of a laser module increases its coverage length, allowing the width of the molten glass ribbon to be covered using fewer laser modules. Significant cost savings can be achieved by using fewer laser modules. In addition, when fewer laser modules are used, congestion in the area adjacent to the molten glass can be reduced. When fewer laser modules are required, the cost of forming the system can be significantly reduced. The angle of each laser module may be unique, and the spacing between modules may be uniform or uneven. The angles may be selected to optimize the performance of a particular ribbon width and / or glass forming mechanism access. In some embodiments, a single module may not be optimal for covering the width of the ribbon. The overall laser power required to generate thickness compensation across the width of the ribbon may prohibit the use of a single module. For example, the laser may be physically too large, which can make cooling the optics too complex and focusing over large scanning angles on the glass too difficult.

[0067] An exemplary system 300 is illustrated in Figure 3, which uses a mounting approach of four laser modules to cover a length of molten glass 302 of 3.5 meters in the width direction. Although the molten glass 302 and the molten glass in Figures 4-8 have a length of 3.5 meters in the width direction, the molten glass may have other lengths in the width direction, and 3.5 meters was selected only for illustrative purposes. The molten glass 302 defines a surface 302A. The first laser module 304 emits a first laser beam extending between a first extreme direction 306A and a second extreme direction 306B, the first laser beam having a central direction 308 between the first extreme direction 306A and the second extreme direction 306B. The central direction 308 has a central strike angle measured with respect to the normal of the surface 302A of the molten glass 302, and this central strike angle is equal to zero degrees. The first scanning angle range of the first laser module 304 is the difference between the scanning angle in the second limiting direction 306B and the scanning angle in the first limiting direction 306A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees. If a beam steering system 248 (see Figure 2C) is used, the scanning angle range may be measured from the reflective surface 214 of the beam steering system 248 (see Figure 2C).

[0068] The second laser module 314 emits a second laser beam extending between the first limiting direction 316A and the second limiting direction 316B, the second laser beam having a central direction 318 between the first limiting direction 316A and the second limiting direction 316B. The central direction 318 has a central strike angle measured with respect to the normal of the surface 302A of the molten glass 302, and this central strike angle is equal to zero degrees. The second scanning angle range of the second laser module 314 is the difference between the scanning angle in the second limiting direction 316B and the scanning angle in the first limiting direction 316A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0069] The third laser module 324 emits a third laser beam extending between the first limiting direction 326A and the second limiting direction 326B, the third laser beam having a central direction 328 between the first limiting direction 326A and the second limiting direction 326B. The central direction 328 has a central strike angle measured with respect to the normal of the surface 302A of the molten glass 302, and this central strike angle is equal to zero degrees. The third scanning angle range of the third laser module 324 is the difference between the scanning angle in the second limiting direction 326B and the scanning angle in the first limiting direction 326A, and in some embodiments, this third scanning angle range may be greater than about 40 degrees.

[0070] The fourth laser module 334 emits a fourth laser beam extending between the first limiting direction 336A and the second limiting direction 336B, the fourth laser beam having a central direction 338 between the first limiting direction 336A and the second limiting direction 336B. The central direction 338 has a central strike angle measured with respect to the normal of the surface 302A of the molten glass 302, and this central strike angle is equal to zero degrees. The fourth scanning angle range of the fourth laser module 334 is the difference between the scanning angle in the second limiting direction 336B and the scanning angle in the first limiting direction 336A, and in some embodiments, this fourth scanning angle range may be greater than about 40 degrees.

[0071] In addition, each of the laser modules 304, 314, 324, and 334 has a module tilt angle of 0 degrees with respect to the normal of the surface 302A of the molten glass 302. The module tilt angle may coincide with the central strike angle of the module when no optical elements (e.g., reflectors such as Garbo) are used to redirect the laser beam. If each of the central strike angles is approximately 0 degrees, complete coverage of 3.5 meters of molten glass 302 may not be achieved with the three laser modules without adjusting the distance of the laser modules to the molten glass 302 or increasing the scanning angle range of each module.

[0072] Another exemplary system 400 using a single mounting approach for three laser modules is illustrated in Figure 4. Each laser module is oriented in a molten glass 402 having a length of 3.5 meters in the width direction. The molten glass 402 defines a surface 402A. The first laser module 404 emits a first laser beam extending between a first extreme direction 406A and a second extreme direction 406B, the first laser beam having a central direction 408 between the first extreme direction 406A and the second extreme direction 406B. The central direction 408 has a central strike angle measured with respect to the normal of the surface 402A of the molten glass 402, and this central strike angle is equal to about 30 degrees. The first scanning angle range of the first laser module 404 is the difference between the scanning angle in the second limiting direction 406B and the scanning angle in the first limiting direction 406A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees.

[0073] The second laser module 414 emits a second laser beam extending between the first limiting direction 416A and the second limiting direction 416B, the second laser beam having a central direction 418 between the first limiting direction 416A and the second limiting direction 416B. The central direction 418 has a central strike angle measured with respect to the normal of the surface 402A of the molten glass 402, and this central strike angle is equal to about 30 degrees. The second scanning angle range of the second laser module 414 is the difference between the scanning angle in the second limiting direction 416B and the scanning angle in the first limiting direction 416A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0074] The third laser module 424 emits a third laser beam extending between the first limiting direction 426A and the second limiting direction 426B, the third laser beam having a central direction 428 between the first limiting direction 426A and the second limiting direction 426B. The central direction 428 has a central strike angle measured with respect to the normal of the surface 402A of the molten glass 402, which is equal to about 30 degrees. The third scanning angle range of the third laser module 424 is the difference between the scanning angle in the second limiting direction 426B and the scanning angle in the first limiting direction 426A, and in some embodiments, this third scanning angle range may be greater than about 40 degrees. Each of the laser modules 404, 414, and 424 has a module inclination angle of 30 degrees with respect to the normal of the surface 402A of the molten glass 402.

[0075] If each of the central strike angles is approximately 30 degrees, complete coverage of 3.5-meter-long molten glass 402 can be achieved with three laser modules. In contrast, with a central strike angle of zero degrees, complete coverage of 3.5-meter-long molten glass requires at least four laser modules, as illustrated in Figure 3.

[0076] Another exemplary system 500 using a different mounting approach for three laser modules is illustrated in Figure 5. Each laser module is oriented in a molten glass 502 having a length of 3.5 meters in the width direction. The molten glass 502 defines a surface 502A. The first laser module 504 emits a first laser beam extending between a first extreme direction 506A and a second extreme direction 506B, the first laser beam having a central direction 508 between the first extreme direction 506A and the second extreme direction 506B. The central direction 508 has a central strike angle measured with respect to the normal of the surface 502A of the molten glass 502, which is equal to approximately -30 degrees. The first scanning angle range of the first laser module 504 is the difference between the scanning angle in the second limit direction 506B and the scanning angle in the first limit direction 506A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees.

[0077] The second laser module 514 emits a second laser beam extending between the first limiting direction 516A and the second limiting direction 516B, the second laser beam having a central direction 518 between the first limiting direction 516A and the second limiting direction 516B. The central direction 518 has a central strike angle measured with respect to the normal of the surface 502A of the molten glass 502, and this central strike angle is equal to about -30 degrees. The second scanning angle range of the second laser module 514 is the difference between the scanning angle in the second limiting direction 516B and the scanning angle in the first limiting direction 516A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0078] The third laser module 524 emits a third laser beam extending between the first limiting direction 526A and the second limiting direction 526B, the third laser beam having a central direction 528 between the first limiting direction 526A and the second limiting direction 526B. The central direction 528 has a central strike angle measured with respect to the normal of the surface 502A of the molten glass 502, which is equal to about -30 degrees. The third scanning angle range of the third laser module 524 is the difference between the scanning angle in the second limiting direction 526B and the scanning angle in the first limiting direction 526A, and in some embodiments, this third scanning angle range may be greater than about 40 degrees. Each of the laser modules 504, 514, and 524 has a module inclination angle of -30 degrees with respect to the normal of the surface 502A of the molten glass 502.

[0079] At a central strike angle of -30 degrees, complete coverage of 3.5-meter-long molten glass 502 can be achieved with three laser modules. In contrast, at a central strike angle of zero degrees, complete coverage of 3.5-meter-long molten glass requires at least four laser modules, as illustrated in Figure 4.

[0080] Another exemplary system 600 using a different mounting approach for three laser modules is illustrated in Figure 6, where each laser module generates a different central strike angle of the laser beam. Each laser module is oriented in molten glass 602 which has a length of 3.5 meters in the width direction. The molten glass 602 defines a surface 602A. The first laser module 604 emits a first laser beam extending between a first extreme direction 606A and a second extreme direction 606B, the first laser beam having a central direction 608 between the first extreme direction 606A and the second extreme direction 606B. The central direction 608 has a central strike angle measured with respect to the normal of surface 602A of the molten glass 602, and this central strike angle is equal to about 30 degrees. The first laser module 604 has a module inclination angle of about 30 degrees with respect to the normal of surface 602A. The first scanning angle range of the first laser module 604 is the difference between the scanning angle in the second limiting direction 606B and the scanning angle in the first limiting direction 606A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees.

[0081] The second laser module 614 emits a second laser beam extending between the first limiting direction 616A and the second limiting direction 616B, the second laser beam having a central direction 618 between the first limiting direction 616A and the second limiting direction 616B. The central direction 618 has a central strike angle measured with respect to the normal of the surface 602A of the molten glass 602, and this central strike angle is equal to about zero degrees. The second laser module 614 has a module inclination angle of about zero degrees with respect to the normal of the surface 602A. The second scanning angle range of the second laser module 614 is the difference between the scanning angle in the second limiting direction 616B and the scanning angle in the first limiting direction 616A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0082] The third laser module 624 emits a third laser beam extending between the first limiting direction 626A and the second limiting direction 626B, the third laser beam having a central direction 628 between the first limiting direction 626A and the second limiting direction 626B. The central direction 628 has a central strike angle measured with respect to the normal of the surface 602A of the molten glass 602, which is equal to about -30 degrees. The third laser module 624 has a module tilt angle of about -30 degrees with respect to the normal of the surface 602A. The third scanning angle range of the third laser module 624 is the difference between the scanning angle in the second limiting direction 626B and the scanning angle in the first limiting direction 626A, and in some embodiments, this third scanning angle range may be greater than about 40 degrees.

[0083] When laser modules 604, 614, and 624 are mounted in the manner illustrated in Figure 6, complete coverage of the 3.5-meter-long molten glass 602 can again be achieved with three laser modules. In addition, with the mounting approach in Figure 6, energy loss may be less in the center of the surface 602A where the second laser beam generated by the second laser module 614 strikes the molten glass 602. Since the laser beams generated by laser modules 604 and 624 may generally need to travel a longer distance to reach the surface 602A, energy loss may be lower in the center of the surface 602A compared to the region closer to the edge of the surface 602A, resulting in less laser power reaching the surface 602A.

[0084] Another exemplary system 700 using a different mounting approach for three laser modules is illustrated in Figure 7. Each laser module is oriented in a molten glass 702 having a length of 3.5 meters in the width direction. The molten glass 702 defines a surface 702A. The first laser module 704 emits a first laser beam extending between a first extreme direction 706A and a second extreme direction 706B, the first laser beam having a central direction 708 between the first extreme direction 706A and the second extreme direction 706B. The central direction 708 has a central strike angle measured with respect to the normal of surface 702A of the molten glass 702, which is equal to about -30 degrees. The first laser module 704 has a module inclination angle of about -30 degrees with respect to the normal of surface 702A. The first scanning angle range of the first laser module 704 is the difference between the scanning angle in the second limit direction 706B and the scanning angle in the first limit direction 706A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees.

[0085] The second laser module 714 emits a second laser beam extending between the first limiting direction 716A and the second limiting direction 716B, the second laser beam having a central direction 718 between the first limiting direction 716A and the second limiting direction 716B. The central direction 718 has a central strike angle measured with respect to the normal of the surface 702A of the molten glass 702, and this central strike angle is equal to about zero degrees. The second laser module 714 has a module inclination angle of about zero degrees with respect to the normal of the surface 702A. The second scanning angle range of the second laser module 714 is the difference between the scanning angle in the second limiting direction 716B and the scanning angle in the first limiting direction 716A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0086] The third laser module 724 emits a third laser beam extending between the first limiting direction 726A and the second limiting direction 726B, the third laser beam having a central direction 728 between the first limiting direction 726A and the second limiting direction 726B. The central direction 728 has a central strike angle measured with respect to the normal of the surface 702A of the molten glass 702, which is equal to about 30 degrees. The third laser module 724 has a module inclination angle of about 30 degrees with respect to the normal of the surface 702A. The third scanning angle range of the third laser module 724 is the difference between the scanning angle in the second limiting direction 726B and the scanning angle in the first limiting direction 726A, and in some embodiments, this third scanning angle range may be greater than about 40 degrees.

[0087] When the laser modules 704, 714, and 724 are mounted in the manner illustrated in Figure 7, complete coverage of the 3.5-meter-long molten glass 702 can again be achieved with the three laser modules. In addition, with the mounting approach in Figure 7, energy loss may be less in the center of surface 702A where the second laser beam generated by the second laser module 714 strikes surface 702A. Furthermore, with the first laser beam generated by the first laser module 704 and the third laser beam generated by the third laser module 724, energy loss may be lower in the region closer to the central portion of surface 702A and increased in the region closer to the extreme edges of surface 702A when the laser beams are required to travel longer distances to these extreme edges of the molten glass 702. In the mounting approach illustrated in Figure 7, the central region of the molten glass 702 (for example, from left to right in Figure 7) can experience greater precision in thickness control compared to other regions of the molten glass 702.

[0088] Another exemplary system 800 using a different mounting approach for two laser modules is illustrated in Figure 8. Each laser module is oriented in molten glass 802 having a length of 3.5 meters in the width direction. The molten glass 802 defines a surface 802A. The first laser module 804 emits a first laser beam extending between a first extreme direction 806A and a second extreme direction 806B, the first laser beam having a central direction 808 between the first extreme direction 806A and the second extreme direction 806B. The central direction 808 has a central strike angle measured with respect to the normal of surface 802A of the molten glass 802, and this central strike angle is equal to about 45 degrees. The first laser module 804 has a module inclination angle of about 45 degrees with respect to the normal of surface 802A. The first scanning angle range of the first laser module 804 is the difference between the scanning angle in the second limiting direction 806B and the scanning angle in the first limiting direction 806A, and in some embodiments, this first scanning angle range may be greater than about 40 degrees.

[0089] The second laser module 814 emits a second laser beam extending between the first limiting direction 816A and the second limiting direction 816B, the second laser beam having a central direction 818 between the first limiting direction 816A and the second limiting direction 816B. The central direction 818 has a central strike angle measured with respect to the normal of the surface 802A of the molten glass 802, which is equal to about -45 degrees. The second laser module 814 has a module inclination angle of about -45 degrees with respect to the normal of the surface 802A. The second scanning angle range of the second laser module 814 is the difference between the scanning angle in the second limiting direction 816B and the scanning angle in the first limiting direction 816A, and in some embodiments, this second scanning angle range may be greater than about 40 degrees.

[0090] When laser modules 804 and 814 are mounted in the manner illustrated in Figure 8, complete coverage of the 3.5-meter-long molten glass 802 can be achieved with the two laser modules. Furthermore, in the first laser beam generated by the first laser module 804 and the second laser beam generated by the second laser module 814, energy loss may be lower in areas closer to the central portion of surface 802A, and increased in areas closer to the extreme edges of surface 802A, as the laser beams are required to travel longer distances to these extreme edges of surface 802A. With this mounting approach, the central region of surface 802A (e.g., from left to right in Figure 8) will experience greater precision in thickness control compared to other regions of surface 802A.

[0091] In some of systems 300, 400, 500, 600, 700, and 800, there is overlap between laser beams generated by adjacent laser modules. For example, in system 300 of Figure 3, the first laser beam generated by the first laser module 304 and the second laser beam generated by the second laser module 314 overlap with each other. In this case, the angular range of one of the laser modules can be precisely adjusted to effectively turn off the energy output in the overlapping region so that the area on the surface of the molten glass in the overlapping region is not in contact with the multiple laser beams. This can be beneficial in avoiding thickness deviations at locations covered by multiple laser beams. In an alternative embodiment, the energy output in the overlapping region can be adjusted for each laser module so that a desired energy output is reached at that location (for example, the first laser module may supply 20% of the desired energy output, while the second laser module may supply the remaining 80%, although any variation between them is intended).

[0092] As illustrated in Figures 3 to 8, increasing the absolute value of the central strike angle of the laser module increases the coverage on the surface of the molten glass. Figure 9 is a line graph 900 illustrating the coverage of the surface of the molten glass by a single module when different module tilt angles and different central strike angles are used. For the results illustrated in line graph 900, the distance between the module and the glass remained constant as the central strike angle changed. In addition, for the results illustrated in line graph 900, the scanning angle range remained constant as the central strike angle changed. Plot line 902 starts with a total coverage of approximately 1.10 meters at a central strike angle of zero degrees. Plot line 902 increases to a total coverage of approximately 1.125 meters at a central strike angle of 15 degrees. The total coverage further increases to approximately 1.25 meters at a central strike angle of 30 degrees. Plot line 902 increases to a total coverage of approximately 1.50 meters at a central strike angle of 40 degrees. Total coverage further increases to approximately 1.875 meters at a central strike angle of 50 degrees. Plot line 902 further increases to a total coverage of approximately 2.75 meters at a central strike angle of 60 degrees. Plot line 902 increases gradually as the central strike angle increases from zero degrees to approximately 30 degrees, but increases at a faster rate as the central strike angle increases further beyond 30 degrees. Increasing the central strike angle to angles above approximately 50 degrees results in even greater coverage levels, however, the incident beam enters the molten glass with shallow incidence when the central strike angle increases beyond approximately 50 degrees. Therefore, the optimal central strike angle can be selected while considering the required coverage and performance level. Line graph 900 is summarized in Table 1 below. [Table 1]

[0093] Figure 10 is a line graph 1000 illustrating the number of modules required to obtain complete coverage of 3.5 meters of molten glass when various center strike angles are used. When the center strike angle is between 0 and 20 degrees, at least four laser modules are required to obtain complete coverage of 3.5 meters of molten glass. The number of laser modules required to obtain complete coverage can decrease as the center strike angle of the laser modules increases. For center strike angles between 25 and 45 degrees, three laser modules are required to obtain complete coverage of 3.5 meters of molten glass. For center strike angles between 50 and 60 degrees, two laser modules are required to obtain complete coverage of 3.5 meters of molten glass.

[0094] In the line graph 1000 of Figure 10, the minimum straight-line distance between the laser module and the molten glass remained constant, while the central strike angle changed (for example, by changing the tilt angle of the module). Coverage can be further increased by moving the laser module further away from the molten glass. However, this may not be an option when the laser module is installed in a confined space.

[0095] Increasing the absolute value of the central strike angle of a laser module can increase the coverage of that laser module, but increasing the absolute value of the central strike angle can cause a reduction in the beam energy supplied to the glass at a particular location, and can also cause a deviation in the beam energy supplied to different locations. These concepts are further illustrated in Figures 17A and 17B. Figures 17A and 17B are schematic diagrams illustrating laser beams striking the surface of molten glass at different angles, and the resulting laser beam shapes. Figures 17A and 17B illustrate laser beams incident on a portion of molten glass so that the laser beam shapes a laser beam shape on the molten glass. Figure 17A illustrates laser beam 1702 incident on a portion of molten glass 1710 so that the laser beam shapes a laser beam shape 1704 on the molten glass 1710. Figure 17B illustrates a laser beam 1706 incident on a portion of the molten glass 1710 so that the laser beam forms a laser beam shape 1708 on the molten glass 1710. The molten glass 1710 is located at the positions indicated by the opposing arrows in both Figure 17A and Figure 17B.

[0096] In Figure 17A, the strike angle of the laser beam 1702 with respect to a portion of the molten glass 1710 is 0 degrees, such that the strike angle is perpendicular to the portion of the molten glass 1710, thereby causing the laser beam 1702 to form a laser beam shape 1704 on the molten glass 1710. The laser beam 1702 has a width w0, and the laser beam shape 1704 has a width w equal to the width w0 of the laser beam 1702. In Figure 17B, the strike angle of the laser beam 1706 with respect to a portion of the molten glass 1710 is greater than 0 degrees, such that the strike angle is oblique to the portion of the molten glass 1710, thereby causing the laser beam 1706 to form a laser beam shape 1708 on the molten glass 1710. The laser beam 1706 has a width w0, and the laser beam shape 1708 has a width w (i.e., w = w0 / cos(θ)) equal to the width w0 of the laser beam 1706 divided by the cosine of the laser angle θ. As shown by the laser beam shape 1704 in Figure 17A and the laser beam shape 1708 in Figure 17B, the energy density of the laser beam 1706 on the surface of the molten glass 1710 is lower in Figure 17B than in Figure 17A. This is due to the increased strike angle of the laser beam 1706 in Figure 17B. As the strike angle of the laser beam increases, the power density of the laser beam on the portion of the molten glass 1710 decreases, thereby causing a non-uniform distribution of laser energy density on the molten glass 1710.

[0097] In addition, Figures 18A and 18B illustrate the lengths the laser beam travels at various angles before reaching the molten glass material. Figures 18A and 18B illustrate the additional distance (indicated by "ΔL") the laser beam travels from the laser beam source 1802 to the molten glass 1804 when the laser beam is at an angle θ from the vertical to the molten glass 1804. The laser beam source 1802 may be an optical element (e.g., a reflector 248 such as a Garbo (see Figure 2C)) if an optical element is used. When the first laser beam 1806 is emitted at an angle perpendicular to the surface of the molten glass 1804, the first laser beam 1806 is required to travel a certain distance L. However, when the second laser beam 1808 is radiated at an angle θ to the surface of the molten glass 1804, the second laser beam 1808 is required to travel a greater distance L' (see Figure 18B), where the difference between distance L' and distance L is ΔL. The geometric shape illustrated in Figure 18A is similar to the geometric shape of system 300 illustrated in Figure 3, and the first laser beam 1806A travels at an angle perpendicular to the molten glass 1804, as with the central directions 308, 318, 328, and 338. The angle θ is zero for the first laser beam 1806. As the absolute value of the angle θ increases, the laser beam begins to travel an additional distance ΔL, and the properties of these laser beams become different from those of the first laser beam 1806A. Figure 18B illustrates another additional distance (indicated by "ΔL'") over which the third laser beam 1810 travels from the laser beam source 1802 to the molten glass 1804. In this example, the third laser beam 1810 is emitted at an angle Φ+θ with respect to the surface of the molten glass 1804, and the third laser beam 1810 is emitted at an angle Φ with respect to the second laser beam 1808. The third laser beam 1810 is required to travel a greater distance, and the difference between this greater distance and distance L' is ΔL'. The geometric shape illustrated in Figure 18B is similar to the geometric shape of the systems illustrated in Figures 4-8, and the scanning angle range is not symmetrical at an angle nearly perpendicular to the molten glass 1804.Instead, the central angle in Figure 18B is (Φ+θ) / 2, and the scanning angle range extends from zero to an angle of Φ+θ. Therefore, the characteristics of the laser beam when scanned at different positions differ due to the additional travel distance as the angle increases from zero to an angle of Φ+θ.

[0098] Figure 11 is a piece graph 1100 illustrating the normalized beam energy fed to the glass at different scanning angles when different central strike angles are used and focus compensation is not used. To obtain the results illustrated in piece graph 1100, neither static focus compensation nor dynamic focus compensation optics is used, and the example shown in Figure 11 shows the results for a system with a system aperture value of approximately 0.01. When used herein, the aperture value is a dimensionless number that characterizes the range of angles at which the system can receive or emit light. In piece graph 1100, the normalized laser beam energy levels are included on the y-axis, and the scanning angle is included in degrees on the x-axis. At higher central strike angles, the beam energy decreased much more rapidly at higher scanning angles. All normalized laser beam energy levels are normalized to the maximum laser beam energy level achieved by plot line 1102 at a scanning angle of approximately 0 degrees.

[0099] When the central strike angle was greater than zero, smaller scanning angles resulted in shorter distances between the laser module and the molten glass compared to larger scanning angles. For example, with a central strike angle of 60 degrees, the distance from the laser module to the molten glass was smaller along a -15 degree scanning angle than along a 0 degree scanning angle, and the distance from the laser module to the molten glass was smaller along a 0 degree scanning angle than along a 15 degree scanning angle.

[0100] At plot line 1102, the central strike angle was zero degrees. Plot line 1102 was at a normalized beam energy of 1.0 at a scanning angle of approximately zero degrees, and remained at a normalized beam energy level of 0.97 or higher at all scanning angles in the range of -15 degrees to 15 degrees.

[0101] At plot line 1104, the central strike angle was 15 degrees. Plot line 1104 started with a normalized beam energy of approximately 1.0 at a scanning angle of -15 degrees. Plot line 1104 decreased to a normalized beam energy of approximately 0.975 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.85 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.025 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, while there was a decrease of approximately 0.125 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 15.0% in the normalized laser beam energy.

[0102] At plot line 1106, the central strike angle was 30 degrees. Plot line 1106 started with a normalized beam energy of approximately 0.93 at a scanning angle of -15 degrees. Plot line 1106 decreased to a normalized beam energy of approximately 0.90 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.65 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.03 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, while there was a decrease of approximately 0.15 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 30.1% in the normalized laser beam energy.

[0103] At plot line 1108, the central strike angle was 45 degrees. Plot line 1108 started with a normalized beam energy of approximately 0.80 at a scanning angle of -15 degrees. Plot line 1108 decreased to a normalized beam energy of approximately 0.78 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.35 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.02 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, while there was a decrease of approximately 0.43 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 56.3% in the normalized laser beam energy.

[0104] At plot line 1110, the central strike angle was 60 degrees. Plot line 1110 started with a normalized beam energy of approximately 0.59 at a scanning angle of -15 degrees. Plot line 1110 showed a slight increase in normalized beam energy to approximately 0.62 at a scanning angle of -5 degrees, and plot line 1110 had a normalized beam energy of approximately 0.60 at a scanning angle of 0 degrees. Plot line 1110 decreased to a normalized beam energy of approximately 0.10 at a scanning angle of 15 degrees. Therefore, the normalized beam energy of plot line 1110 was almost the same at scanning angles of -15 degrees and 0 degrees, but the normalized beam energy of plot line 1110 decreased significantly to approximately 0.1 at a scanning angle of 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 83.1% in the normalized laser beam energy. When a central strike angle of 50 degrees or greater is used, the laser beam may strike the glass with shallow incidence, significantly reducing energy density and process resolution. Line graph 1100 is summarized in Table 2 below. [Table 2]

[0105] As illustrated in Table 2, the magnitude of the percentage decrease in normalized laser beam energy increased as the central strike angle increased beyond 60 degrees. One reason for this change is the difference in distance between the laser module and the molten glass at scanning angles of -15 degrees and 15 degrees, where this distance is greater at 15 degrees.

[0106] In various embodiments contemplated herein, static focus compensating optical systems and / or dynamic focus compensating optical systems may be integrated into the system. By using static focus compensating optical systems and / or dynamic focus compensating optical systems, systems using laser modules oriented at a high central strike angle may have increased laser beam energy compared to other equivalent systems that do not use static focus compensating optical systems or dynamic focus compensating optical systems. In some embodiments, systems having static focus compensating optical systems and / or dynamic focus compensating optical systems may have a system aperture numerical value of about 0.01 or greater. In this case, the static focus compensating or dynamic focus compensating optical system can rapidly adjust the spot size of the laser beam to compensate for any beam divergence caused by an increase in the optical path length of the laser beam. When higher spatial resolution is required to achieve desired thickness control, a system with a numerical aperture of about 0.01 or greater may be advantageous. For example, a smaller spot may result in a narrower thermally affected zone and provide greater thickness control resolution. When the system numerical aperture is about 0.01 or greater, static focus compensating optical systems and / or dynamic focus compensating optical systems are particularly useful for improving thickness control resolution. When the system numerical aperture is less than approximately 0.01, the static and dynamic focus adaptive optics systems have reduced impact because the generated beam is effectively collimated, and in many cases, the extra optical path length is irrelevant.

[0107] Figure 12 is a piecewise graph illustrating the normalized beam energy at different scanning angles on the surface of molten glass when different central strike angles are used and focus compensation is employed. Static and / or dynamic focus compensation optics were used to obtain the results illustrated in piecewise graph 1200. The static and / or dynamic focus compensation optics significantly reduced the decrease in laser beam energy when using larger central strike angles (in terms of absolute value).

[0108] In line graph 1200, the normalized laser beam energy level is included on the y-axis, and the scanning angle is included in degrees on the x-axis. At larger central strike angles (in terms of absolute value), the beam energy decreased more rapidly at higher scanning angles. All normalized laser beam energy levels are normalized to the maximum laser beam energy level achieved by plot line 1202 at a scanning angle of approximately 0 degrees.

[0109] When the central strike angle was greater than zero, smaller scanning angles resulted in shorter distances between the laser module and the molten glass compared to larger scanning angles. For example, with a central strike angle of 60 degrees, the distance from the laser module to the molten glass was smaller at a scanning angle of -15 degrees than at a scanning angle of 0 degrees, and the distance was smaller at a scanning angle of 0 degrees than at a scanning angle of 15 degrees. In contrast, when the central strike angle was less than zero, smaller scanning angles resulted in larger distances between the laser module and the molten glass compared to larger scanning angles.

[0110] At plot line 1202, the central strike angle was zero degrees. Plot line 1202 was at a normalized beam energy of 1.0 at a scanning angle of approximately zero degrees, and remained at a normalized beam energy level of approximately 0.98 or higher at all scanning angles in the range of -15 degrees to 15 degrees.

[0111] At plot line 1204, the central strike angle was 15 degrees. Plot line 1204 started with a normalized beam energy of approximately 1.0 at a scanning angle of -15 degrees. Plot line 1204 decreased to a normalized beam energy of approximately 0.97 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.90 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.03 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, and a decrease of approximately 0.07 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 10.0% in the normalized laser beam energy.

[0112] At plot line 1206, the central strike angle was 30 degrees. Plot line 1206 started with a normalized beam energy of approximately 0.98 at a scanning angle of -15 degrees. Plot line 1206 decreased to a normalized beam energy of approximately 0.90 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.78 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.08 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, and a decrease of approximately 0.12 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The normalized laser beam energy decreased by approximately 20.4% with the change in scanning angle from -15 degrees to 15 degrees.

[0113] At plot line 1208, the central strike angle was 45 degrees. Plot line 1208 started with a normalized beam energy of approximately 0.91 at a scanning angle of -15 degrees. Plot line 1208 decreased to a normalized beam energy of approximately 0.78 at a scanning angle of 0 degrees, and then decreased to a normalized beam energy of approximately 0.60 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.13 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, and a decrease of approximately 0.18 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 34.1% in the normalized laser beam energy.

[0114] At plot line 1210, the central strike angle was 60 degrees. Plot line 1210 started with a normalized beam energy of approximately 0.79 at a scanning angle of -15 degrees. Plot line 1210 had a normalized beam energy of approximately 0.60 at a scanning angle of 0 degrees. Plot line 1210 decreased to a normalized beam energy of approximately 0.30 at a scanning angle of 15 degrees. Therefore, there was a decrease of approximately 0.19 in the normalized beam energy from a scanning angle of -15 degrees to 0 degrees, and a decrease of approximately 0.30 in the normalized beam energy from a scanning angle of 0 degrees to 15 degrees. The change in scanning angle from -15 degrees to 15 degrees resulted in a decrease of approximately 62.0% in the normalized laser beam energy. Line graph 1200 is summarized in Table 3 below. [Table 3]

[0115] A comparison of Tables 2 and 3 reveals that the use of focus compensation improved the normalized laser beam energy at a 15-degree scanning angle and also helped reduce the percentage decrease value. The percentage decrease value of the normalized laser beam energy from scanning angles of -15 to 15 degrees was improved by focus compensation, but these decreases were not eliminated by focus compensation. The remaining decreases are at least partially caused by cosine errors and Fresnel reflections caused by large strike angles. The fluctuations can be at least partially improved by modulating the laser power versus scanning field to adjust for the power lost from Fresnel reflections. The output energy of the laser module can increase during laser scanning as the strike angle increases (for example, the output energy can be higher when the laser beam is directly at an angle perpendicular to the surface of the molten glass than in other scenarios where the laser beam is directed at other angles not perpendicular to the surface of the molten glass), which can compensate for the beam energy naturally reflected from the glass due to the high incidence angle.

[0116] In addition, these variations can be mitigated, at least partially, by a beam compensation optics system and a spatial light modulator 1302G (see Figure 13) to compensate for off-axis beam distortion. Off-axis scanning introduces cosine error beam distortion on the glass, which can be addressed, at least partially, by positioning a tool such as the spatial light modulator 1302G in the beam path, and the spatial light modulator 1302G is synchronized with other beam steering optics. The spatial light modulator 1302G can compensate for off-axis distortion with a high response speed by modifying the shape of the laser beam. The spatial light modulator 1302G can operate at frequencies of approximately 50 Hz to 110 Hz, approximately 60 Hz to 100 Hz, or approximately 70 Hz to 90 Hz. In addition to or instead of this, diffractive optical elements 1302H (see Figure 13) may be used to modify the incident phase front to a predetermined profile through optical interference effects, and these diffractive optical elements 1302H may be custom-designed for a particular system in some embodiments. The diffractive optical elements 1302H may also be configured to compensate for cosine errors caused by large glass incident angles. However, in some embodiments, the diffractive optical elements 1302H may be omitted, and optical elements 1304 may be used instead to compensate for cosine errors. In some embodiments, optical elements 1304 may not be included.

[0117] Figure 13 is a block diagram illustrating an exemplary laser beam control system 1300. The system 1300 may be used to provide closed-loop control of the thickness of molten glass during glass forming. The system 1300 includes one or more thickness sensors 1308. The thickness sensors 1308 measure the thickness of the molten glass 1306 as the glass is being formed in order to obtain a thickness trace. However, in some embodiments, the thickness sensors 1308 may measure the thickness of the molten glass 1306 after it has become partially cooled glass, or on cut, fully cooled glass. The thickness traces received by the thickness sensors 1308 are then communicated by the thickness sensors 1308 to one or more thickness control units 1310. The thickness control units 1310 may help maintain a glass thickness close to a desired target. In some embodiments, the thickness control units 1310 may reflect a variety of variables that affect the thickness of the molten glass 1306. The thickness control unit(s) 1310 may receive a target thickness profile from one or more memory units 1312. In some embodiments, the target thickness profile may target a uniform thickness across the width of the molten glass. However, in other embodiments, the target thickness profile may target a variable thickness across the width of the molten glass. For example, the target thickness profile may define parabolic curvature, quadratic curvature, sinusoidal curvature, etc. The thickness control unit(s) 1310 may also receive other data from the memory units 1312.

[0118] Based on available input information such as a target thickness profile and any thickness trace, the thickness control unit(s) 1310 may generate a power profile, which may be configured to transmit to one or more laser and galvanometer control units(s) 1314. This power profile is configured to be used to control the operation of the laser module(s) 1302. The laser and galvanometer control units(s) 1314 may then cause the laser module(s) 1302 to apply power, which is applied to specific locations to achieve the glass thickness according to the power profile. The laser module(s) 1302 generates a laser beam, which may, in some embodiments (e.g., without the illustrated optical element(s) 1304), be radiated directly toward the molten glass 1306. However, in other embodiments, such as the embodiment illustrated in Figure 13, one or more optical elements 1304 may be included to redirect the laser beam toward the molten glass 1306, similar to the one illustrated in Figure 2C. The use of optical elements 1304 may be beneficial when there is limited space available in close proximity to the molten glass 1306. While optical elements 1304 may include reflectors in some embodiments, they may also include other elements such as optical lenses and refractive elements, either in addition to or instead of reflectors. Positioning the laser module 1302 in close proximity to the molten glass 1306 to increase the amount of laser energy on the surface of the molten glass 1306 may be beneficial even when optical elements are used. Although the optical elements (or multiple elements) 1304 are illustrated as separate components from the laser module (or multiple elements) 1302 in Figure 13, in some embodiments, one or more of the optical elements (or multiple elements) 1304 may be provided within the laser module (or multiple elements) 1302.

[0119] Each laser module 1302 may optionally include a laser unit 1302A, a multiplexer unit 1302B, a dynamic focus unit 1302C, a beam splitter unit 1302D, an acousto-optic modulator 1302E, an electro-optic modulator 1302F, a spatial light modulator 1302G, and / or a diffractive optical element 1302H. The laser unit 1302A may be a unit within the laser module 1302 that generates a laser beam. The multiplexer unit 1302B may multiplex one or more laser beams. The multiplexer unit 1302B may be a time-based multiplexer that routes the laser beam across various paths in time. Alternatively, the multiplexer unit 1302B may be a spatial multiplexer that routes the laser beam across various paths simultaneously. The multiplexer unit 1302B may operate, for example, temporally, spatially, or spatiotemporally. In some examples, the multiplexer unit 1302B may be configured to route the laser beam along various paths. Multiplexing the laser beam can offer one or more advantages, such as enabling scaling of the laser beam control system.

[0120] The dynamic focusing unit 1302C may be configured to compensate for changes in distance from the laser module 1302 to the molten glass 1306. The beam splitter unit 1302D may enable the laser to be optically coupled to two or more optical fibers. In some further embodiments, all optical fibers may be optically coupled to a single laser using a series of beam splitters.

[0121] In some embodiments, the laser module(s) 1302 may comprise at least one modulation device, such as an acousto-optic modulator 1302E or an electro-optic modulator 1302F. However, in other embodiments, the acousto-optic modulator 1302E and / or the electro-optic modulator 1302F may be positioned at other locations in the system 1300. The acousto-optic modulator 1302E and the electro-optic modulator 1302F can rapidly modulate a continuous laser beam, providing improved power control, as well as inter-pulse stability and repeatability. Pulse width modulation strategies using standard pulsed lasers frequently lead to over / undershoot of pulse amplitude between triggers, which can add process noise and lead to reduced thickness control capability. However, tools such as the acousto-optic modulator 1302E and the electro-optic modulator 1302F can be used to externally gate the laser pulses. When acousto-optic modulators 1302E and / or electro-optic modulators 1302F are used, the laser module(s) 1302 may fire continuously on a fixed duty cycle, and the pulse width may be modulated by the high-speed acousto-optic modulators 1302E and / or electro-optic modulators 1302F. This may result in pulses with sharp, repeatable rise / fall characteristics, which may also minimize pulse over / undershoot anomalies. The use of acousto-optic modulators 1302E and / or electro-optic modulators 1302F may also result in more consistent / repeatable performance from precision thickness-controlled laser systems and may simplify closed-loop control automation strategies. Acousto-optic modulators 1302E and / or electro-optic modulators 1302F may also be used to compensate for Fresnel reflection power loss caused by large strike angles due to tilted modules, in order to maintain similar energy density across the scanning field. A system including the acousto-optic modulator 1302E and / or the electro-optic modulator 1302F can maintain a more uniform energy density on the molten glass surface compared to other identical systems that do not include the acousto-optic modulator or the electro-optic modulator.

[0122] In addition, the laser module(s) 1302 may include a spatial light modulator 1302G and / or a diffractive optical element 1302H. The beam compensation optics and spatial light modulator 1302G may be used to compensate for off-axis beam distortion. Off-axis scanning introduces cosine error beam distortion into the glass. To compensate for this beam distortion, tools such as the spatial light modulator 1302G may be incorporated into the beam path and synchronized with other beam steering optics. The spatial light modulator 1302G can modify the beam shape of the laser beam to compensate for off-axis distortion with a high response speed. In addition to or instead of this, the diffractive optical element 1302H may be used to modify the beam shape through optical interference effects, and the diffractive optical element 1302H may be custom-designed for a particular system in some embodiments. The diffractive optical element 1302H may also be configured to compensate for cosine error caused by large glass incidence angles.

[0123] While the laser energy may vary at different points along the laser beam as the laser module is tilted at a certain angle, system 1300 can compensate for this. For example, a thickness control unit 1310 or another unit can calculate the expected power density of the laser beam based on the incident angle of the laser beam. For instance, a thickness control unit 1310 can cause a power increase in the generated laser beam at some or all points along the laser beam in the laser and galvanometer control units 1314. Thus, system 1300 can maintain the same or similar power density as the laser beam is scanned across the molten glass.

[0124] Figure 14 is a piece graph 1400 illustrating an exemplary Gaussian response model of the thickness profile response of molten glass to laser power. This piece graph 1400 is merely a model and not a measured response. In the illustrated example, the thickness profile response is input to change the thickness profile at the 500 mm position. As illustrated, the plotted line 1402 remains at approximately 0 mm / W from the 0 mm position to approximately 475 mm, so these positions are generally unaffected by the thickness profile response. At approximately 475 mm, the mm / W value begins to decrease rapidly, and this value decreases to approximately -5 mm / W at the approximately 500 mm position. The mm / W value increases to approximately 0 mm / W at the approximately 525 mm position. The mm / W value remains at zero from approximately 525 mm to the 1000 mm position, so these positions are generally unaffected by the thickness profile response. The response model in line graph 1400 is attributed to the incidence of a far-infrared laser (e.g., a CO2-based laser) focused on a spot of approximately 5 millimeters and incident on the molten glass ribbon at a position of 500 millimeters. The glass response can be a function of composition, flow rate, temperature, cooling curve, and other stretching parameters.

[0125] Figure 15 is a piece graph 1500 illustrating an exemplary double Gaussian response model of the thickness profile response of molten glass to laser power. This piece graph 1500 is merely a model and not a measured response. In the exemplary example, the thickness profile response is input to change the thickness profile at the 500 mm position. As illustrated, the plotted line 1502 remains at approximately 0 mm / W from the 0 mm position to approximately 450 mm, so these positions are generally unaffected by the thickness profile response. At approximately 450 mm, the mm / W value begins to increase, and this value increases to approximately 0.75 mm / W at approximately 475 mm. Then, at approximately 500 mm, the mm / W value decreases rapidly to approximately -5 mm / W. The mm / W value increases to approximately 0.75 mm / W at approximately 525 mm. Subsequently, plot line 1502 decreases from approximately 550 mm to a level of approximately 0 mm / W and remains at that level up to 1000 mm, so these positions are generally unaffected by the thickness profile response. While Gaussian and double Gaussian response models are intended, other response models may also be used. For example, response models may be based on raised cosine functions, Bessel functions, etc.

[0126] Furthermore, closed-loop control tests were performed to evaluate the potential performance and stability of the scheme under closed-loop control. Figure 16 is a line graph illustrating exemplary thickness errors before and after the closed-loop control test. The test was performed for approximately 12 hours or 720 minutes. The thickness error can be evaluated by subtracting the minimum thickness from the maximum thickness over a 100 mm travel range window. In some embodiments, the thickness is measured in 5 mm increments across the glass, and the minimum and maximum thicknesses can be determined from these measurements.

[0127] Different control intervals can be used. For example, the control interval may be approximately 10 minutes, but it can be changed to 5 minutes, 8 minutes, 15 minutes, or 20 minutes. Although the base control interval for the test results illustrated in Figure 16 was set to 10 minutes, the interval may be set to other periods (e.g., 1 minute, 2 minutes, 5 minutes, 15 minutes, 60 minutes, 240 minutes, 12 hours, 24 hours, 2 days, 3 days, etc.). By using a base control interval of 10 minutes, the actuator may have superior resolution and response speed compared to other systems using higher base control intervals.

[0128] The current version of the system implements a cost function that may be quadratic or non-quadratic. For example, the cost function may consider the range window value for the maximum thickness (e.g., the maximum thickness within a 100 mm range window) and / or the standard deviation of the predicted thickness change, and the cost function is generally set to be a weighted combination of one of the range windows for the maximum thickness. Other cost functions may be used. The problem to be solved is an optimization constraint, given by the maximum acceptable change in the power profile per control interval and the maximum power that the laser can generate.

[0129] Line graph 1600 includes plotted lines 1602 and 1604. Plotted line 1602 illustrates the maximum thickness error within a 100 mm movement range window where closed-loop control was not provided, and plotted line 1604 illustrates the maximum thickness error within a 100 mm movement range window where closed-loop control was provided. Both plotted lines 1602 and 1604 start at a thickness error of approximately 2.5 micrometers. Plotted line 1602 generally remains around an average of 2.52 micrometers throughout the entire 720-minute period illustrated in graph 1600, with the maximum thickness error ranging from approximately 1.75 micrometers to approximately 3.8 micrometers. In contrast, plotted line 1604 generally remains around an average of 1.32 micrometers throughout the entire 720-minute period illustrated in graph 1600, with the maximum thickness error ranging from approximately 0.6 micrometers to 2.4 micrometers (when values ​​at time zero are excluded). This flatness control system can improve both long-term and short-term variations in molten glass thickness. Graph 1600 illustrates that under closed-loop control, the average thickness error was reduced by approximately 47.62%, and the maximum thickness error over a 720-minute window was reduced by approximately 36.84%. In addition, other noise filtering techniques can be implemented to further improve controller capabilities beyond the results shown in Figure 16.

[0130] Returning to Figure 19, Chart 1900 is illustrated by curve 1902, which shows the percentage of the additional distance (ΔL) the laser beam must travel relative to the original distance (indicated by "L"), where zero degrees is perpendicular to the surface of the molten glass, as the laser beam is emitted at different angles relative to the direction perpendicular to the surface of the molten glass. At an angle of zero degrees, the percentage value of ΔL / L is zero. From an angle of 0 degrees to about 20 degrees, the percentage value of ΔL / L remains about zero. At an angle of about 40 degrees, the percentage value of ΔL / L increases to about 25 percent. At an angle of about 50 degrees, the percentage value of ΔL / L increases to about 60 percent. At larger angles, the percentage value of ΔL / L increases even more rapidly. As ΔL / L increases to higher levels, beam intensity fluctuations across the scanning angle range become more pronounced due to focal and cosine errors, and it may be beneficial to utilize further techniques to compensate for these focal and cosine errors.

[0131] Figure 20 is a flowchart illustrating exemplary methods for manufacturing a laser thickness control system according to some embodiments discussed herein. In operation 2002, a glass molded body is provided, which is configured to facilitate the shaping of the glass. The glass molded body allows molten glass to flow along at least one surface of the glass molded body to form a glass ribbon containing the molten glass. The molten glass defines a first surface having a width extending from a first edge to a second edge, which may be positioned above the root of the glass molded body or below the root of the glass molded body.

[0132] In operation 2004, a first laser module is provided. This laser module may be configured to generate a first laser beam. The first laser module may be configured to cause scanning of the first laser beam at least partially aligned with the width of a first surface within a scanning angle to apply heat to assist in controlling the thickness of the glass ribbon being formed into glass. In operation 2006, the first laser module is positioned so that the first laser module directs the first laser beam toward a surface of molten glass, the surface defining a normal direction perpendicular to the surface. The first laser module may cause scanning of the first laser beam at least partially aligned with the width of the first surface within a scanning angle range to apply heat to assist in controlling the thickness of the glass ribbon being formed into glass. Method 2000 may cause shaping of the system in which, when the first laser beam strikes the surface of molten glass, the first laser beam travels in a direction facing the first center. The first angle may be defined by the direction facing the first center and the normal direction, and this first angle may be greater than zero degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 50 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 45 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 40 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 35 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 30 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 25 degrees. In some embodiments, this first angle may be greater than zero degrees and less than about 20 degrees.

[0133] In operation 2008, optionally, a second laser module may be provided, which may be configured to generate a second laser beam. The second laser module may be configured to cause scanning of the second laser beam at least partially aligned with the width of the first surface within a scanning angle range, in order to apply heat to assist in controlling the thickness of the glass ribbon being formed into glass. In operation 2010, the second laser module may be positioned to direct the second laser beam toward the surface of the molten glass. The second laser module may cause scanning of the second laser beam at least partially aligned with the width of the first surface within a scanning angle range, in order to apply heat to assist in controlling the thickness of the glass ribbon being formed into glass. Method 2000 may result in the shaping of a system in which the second laser beam travels in a second direction when the second laser beam strikes the surface of the molten glass. The second angle may be defined by the second direction and the normal direction. In some embodiments, the second angle may be equal to the first angle, but in some embodiments, the second angle may be different from the first angle. In some embodiments, the second angle may be zero.

[0134] conclusion Those skilled in the art, who benefit from the teachings presented in the foregoing description and accompanying drawings, will likely envision many modifications and other embodiments described herein. It will be understood that the embodiments are not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to fall within the scope of the invention. Furthermore, while the foregoing description and accompanying drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the invention. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also intended within the scope of the invention. Certain terms are used herein, but they are used only in a general and descriptive sense and not for limiting purposes.

Claims

1. A system for forming glass ribbons, wherein the system is A glass molded body, configured to allow molten glass to flow along the surface of the glass molded body to form a glass ribbon, wherein the glass ribbon defines a first surface having a width extending from a first edge to a second edge, A first laser module is configured to generate a first laser beam that is scanned at least partially along the width of the first surface within a first scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon, and comprises A system in which the direction of the first laser beam facing the first center of the first scanning angle range strikes the first surface at a first central strike angle that is not perpendicular to the first surface.

2. The system according to claim 1, wherein the first laser beam extends at least partially along the width of the glass ribbon between the first edge and the second edge, the first scanning angle range is equal to the angular range between the first scanning angle and the second scanning angle, the first scanning angle is the minimum angle at which a portion of the first laser beam strikes the first surface, and the second scanning angle is the maximum angle at which a portion of the first laser beam strikes the first surface.

3. The system according to claim 2, wherein the first scanning angle range is greater than approximately 40 degrees.

4. The system according to any one of claims 1 to 3, wherein the first central strike angle is measured with respect to the normal direction of the first surface, and the first central strike angle is greater than zero degrees and less than about 50 degrees.

5. The system according to any one of claims 1 to 3, wherein the first laser beam causes an increase in the temperature of the glass ribbon in the affected region, the increase in temperature causes a decrease in the viscosity of the glass ribbon in the affected region, and the decrease in the viscosity of the glass ribbon causes a decrease in the thickness of the glass ribbon in the affected region.

6. A second laser module further comprises a second laser module configured to generate a second laser beam scanned at least partially along the width of the first surface within a second scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon. The system according to any one of claims 1 to 3, wherein the direction of the second laser beam facing the second center of the second scanning angle range strikes the first surface at a second central strike angle.

7. The system according to claim 6, wherein the first center strike angle and the second center strike angle are the same.

8. The system according to claim 6, wherein the first center strike angle and the second center strike angle are different.

9. The system according to claim 8, wherein the second central strike angle is equal to zero.

10. It further comprises at least one optical element, The system according to any one of claims 1 to 3, wherein the first laser module is configured to radiate the first laser beam toward the at least one optical element, and the at least one optical element is configured to redirect the first laser beam toward the first surface.

11. The system according to claim 10, wherein the at least one optical element comprises a reflector.

12. The adjustment mechanism is further configured to adjust the orientation of at least one optical element, The system according to claim 10 or 11, wherein adjusting the orientation of the at least one optical element causes a change in the position in which the laser beam contacts the first surface of the glass ribbon.

13. A thickness sensor configured to determine the thickness of the glass ribbon at one or more locations, It further includes a thickness control unit, The system according to any one of claims 1 to 3, wherein the thickness control unit is configured to receive thickness data from the thickness sensor, the thickness control unit is configured to receive a target thickness profile, the thickness control unit is configured to generate a power profile based on at least the thickness data and the target thickness profile, and the power profile is configured to be used to control the operation of the first laser module.

14. The system according to any one of claims 13, wherein the target thickness profile maintains a uniform thickness over the width of the glass ribbon.

15. The system according to any one of claims 13, wherein the target thickness profile maintains a variable thickness over the width of the glass ribbon.

16. The system further comprises at least one of an acoustic-optic modulator or an electro-optic modulator, The system according to any one of claims 1 to 3, wherein the acoustic-optic modulator and the electro-optic modulator are configured to modulate the generated laser beam to generate the first laser beam.

17. The system according to claim 16, wherein the first central strike angle is equal to about 30 degrees, the first laser beam strikes the first surface at minimum and maximum energy densities, the minimum energy density being less than about 21 percent of the maximum energy density.

18. The device further comprises at least one of a spatial light modulator or a diffractive optical element, The system according to any one of claims 1 to 3, wherein the spatial light modulator or the diffractive optical element is configured to compensate for cosine errors caused by large glass incidence angles.

19. The system according to any one of claims 1 to 3, wherein the glass molded body includes a root portion, and the first laser beam strikes the first surface below the root portion of the glass molded body.

20. The system according to any one of claims 1 to 3, wherein the glass molded body includes a root portion, and the first laser beam strikes the first surface on the root portion of the glass molded body.

21. The system according to any one of claims 1 to 3, wherein the first laser beam includes light having a wavelength of about 400 nanometers to about 11,000 nanometers.

22. A method for manufacturing a system for providing laser thickness control, wherein the method is A glass molded body is provided, wherein the glass molded body is configured to allow molten glass to flow along at least one surface of the glass molded body to form a glass ribbon, and the molten glass defines a first surface having a width extending from a first edge to a second edge. A first laser module is provided, wherein the first laser module is configured to generate a first laser beam that is scanned at least partially along the width of the first surface within a scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon. Positioning the first laser module such that it directs the first laser beam toward the first surface, A method comprising defining a normal direction perpendicular to the first surface, and positioning the first laser module such that the direction of the first laser beam facing the center of the scanning angle range strikes the first surface at a central strike angle that is not perpendicular to the first surface.

23. A second laser module is provided, wherein the second laser module is configured to generate a second laser beam that is scanned at least partially along the width of the first surface within a second scanning angle range, so as to apply heat to assist in controlling the thickness of the glass ribbon. The method according to claim 22, further comprising positioning the second laser module such that the second laser module directs the second laser beam toward the first surface.

24. A laser system for forming glass ribbons, wherein the laser system is A first laser module is provided, configured to generate a first laser beam that scans at least partially along the width of a first surface of a glass ribbon, wherein molten glass flows along the surface of a glass molded body to form the glass ribbon, and the glass ribbon defines a first surface having the width extending from a first edge to a second edge. The first laser beam is scanned within a first scanning angle range along the width so as to apply heat to assist in controlling the thickness of the glass ribbon. A laser system in which the first laser beam is aimed along the width such that the direction of the first laser beam facing the first center of the first scanning angle range strikes the first surface at a first central strike angle that is not perpendicular to the first surface.

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