Method and apparatus for manufacturing glass ribbon

Abstract

A method of manufacturing a glass ribbon is provided, including moving a ribbon of glass-forming material along a path of travel in a travel direction. The method includes detecting the thickness of the ribbon of glass-forming material at a plurality of locations of the ribbon of glass-forming material. The method includes identifying a location of the plurality of locations, wherein a corresponding thickness at the location exceeds a target thickness. The method includes correlating a thickness change rate and a thickness difference between the corresponding thickness and the target thickness with a laser power. The method includes directing a laser beam toward the ribbon of glass-forming material at the laser power to reduce viscosity at the location and achieve the target thickness at the location.

Description

Technical Field

[0001] This case claims priority under the Patent Act to U.S. Provisional Application No. 62 / 942,258 filed on December 2, 2019, the contents of which are relied upon and incorporated herein by reference in their entirety.

[0002] The present disclosure relates generally to methods for making glass ribbons, and more particularly, to methods for making glass ribbons by controlling the thickness of the glass ribbons. Background Art

[0003] It is known that a glass making device is used to make a glass ribbon from a molten material. In order to produce a glass ribbon having a target thickness, the thickness of the glass ribbon may be measured. However, if the thickness at a position of the glass ribbon deviates from the target thickness, measuring the thickness of the glass ribbon may require adjusting the thickness at this position of the glass ribbon. Summary of the invention

[0004] The following presents a simplified summary of the disclosure in order to provide a basic understanding of some embodiments described in the detailed description.

[0005] In some embodiments, a method of manufacturing a glass ribbon may include a control device that can control the thickness of the glass forming material ribbon. The thickness sensor can detect the thickness as the glass forming material ribbon moves along a travel path in the travel direction, or in some embodiments, the thickness sensor can detect the thickness after the first ribbon portion is separated. The control device can identify any position of the glass forming material ribbon that deviates from the target thickness. The control device can control the laser device and / or cooling tube to provide localized heating and / or cooling to the glass forming material ribbon. The control device can further take into account any time delays and / or process disturbances that may occur, thereby providing more accurate thickness control of the glass forming material ribbon.

[0006] According to some embodiments, a method of manufacturing a glass ribbon may include moving a ribbon of glass-forming material along a path of travel in a travel direction. The method may include detecting a thickness of the ribbon of glass-forming material at a plurality of locations of the ribbon of glass-forming material. The method may include identifying a location of the plurality of locations where a corresponding thickness at the location exceeds a target thickness. The method may include correlating a thickness change rate and a thickness difference between the corresponding thickness and the target thickness to a laser power. The method may include directing a laser beam toward the ribbon of glass-forming material at the laser power to reduce viscosity at the location and achieve the target thickness at the location.

[0007] In some embodiments, identifying may include identifying a second location among the plurality of locations, wherein a second corresponding thickness at the second location is less than the target thickness.

[0008] In some embodiments, the method may include directing a cooling fluid toward the ribbon of glass forming material to increase viscosity at the second location and to achieve a target thickness at the second location.

[0009] In some embodiments, the method may include flowing a first stream of glass forming material over a first weir of a forming wedge. The method may include flowing a second stream of glass forming material over a second weir of a forming wedge. The method may include fusing the first stream of glass forming material and the second stream of glass forming material to form a molten ribbon.

[0010] In some embodiments, directing the laser beam may include directing the laser beam toward one or more of a first flow of glass-forming material flowing over a first weir, a second flow of glass-forming material flowing over a second weir, or a molten ribbon.

[0011] In some embodiments, sensing the thickness of the ribbon of glass-forming material may occur at a plurality of locations spaced apart along a first axis generally perpendicular to the direction of travel.

[0012] In some embodiments, detecting the thickness of the ribbon of glass forming material may occur in the first ribbon portion of the ribbon of glass forming material after separating the first ribbon portion from the second ribbon portion of the ribbon of glass forming material.

[0013] According to some embodiments, a method of manufacturing a glass ribbon may include moving a ribbon of glass-forming material along a path of travel in a direction of travel. The method may include detecting a thickness of the ribbon of glass-forming material at a plurality of locations of the ribbon of glass-forming material. The method may include identifying a first location of the plurality of locations and a second location of the plurality of locations, wherein a first corresponding thickness at the first location exceeds a target thickness, and wherein a second corresponding thickness at the second location is less than the target thickness. The method may include directing a laser beam toward the ribbon of glass-forming material to reduce viscosity at the first location and to achieve a target thickness at the first location. The method may include directing a cooling fluid toward the ribbon of glass-forming material to increase viscosity at the second location and to achieve a target thickness at the second location.

[0014] In some embodiments, the method may include flowing a first stream of glass forming material over a first weir of a forming wedge. The method may include flowing a second stream of glass forming material over a second weir of a forming wedge. The method may include fusing the first stream of glass forming material and the second stream of glass forming material to form a molten ribbon.

[0015] In some embodiments, directing the laser beam may include directing the laser beam toward one or more of a first flow of glass-forming material flowing over a first weir, a second flow of glass-forming material flowing over a second weir, or a molten ribbon.

[0016] In some embodiments, detecting the thickness of the ribbon of glass forming material may occur in the first ribbon portion of the ribbon of glass forming material after separating the first ribbon portion from the second ribbon portion of the ribbon of glass forming material.

[0017] In some embodiments, the method may include calculating a time delay between separation of the first tape portion and thickness detection. The method may include directing a laser beam and a cooling fluid toward the second tape portion in dependence upon the time delay.

[0018] According to some embodiments, a method of manufacturing a glass ribbon may include moving a ribbon of glass forming material along a path of travel in a travel direction. The method may include separating a first ribbon portion of the ribbon of glass forming material from a second ribbon portion of the ribbon of glass forming material. The method may include detecting thickness at a plurality of locations of the first ribbon portion. The method may include identifying a first location of a plurality of locations where a corresponding thickness at the first location exceeds a target thickness. The method may include calculating a time delay between separation of the first ribbon portion and thickness detection. The method may include directing a laser beam at a laser power based on the time delay toward a second location of the second ribbon portion corresponding to the first location of the first ribbon portion to reduce viscosity at the second location and achieve a target thickness at the second location.

[0019] In some embodiments, a method may include generating a predicted thickness profile for a ribbon of glass forming material, the predicted thickness profile including predicted thicknesses at a plurality of locations.

[0020] In some implementations, identifying the first location can include comparing the predicted thickness profile to thicknesses detected at a plurality of locations.

[0021] In some embodiments, the method may include generating a second thickness profile for the second belt portion based on a comparison between the predicted thickness profile and the thicknesses detected at the plurality of locations.

[0022] In some implementations, the method may include identifying a third location in the plurality of locations, wherein a third corresponding thickness at the third location is less than the target thickness.

[0023] In some embodiments, the method may include directing cooling fluid toward a fourth location of the second tape portion corresponding to the third location of the first tape portion to increase viscosity at the fourth location and achieve a target thickness at the fourth location.

[0024] In some embodiments, a method of manufacturing a glass ribbon may include moving a ribbon of glass-forming material along a path of travel in a travel direction. The method may include detecting a thickness of the ribbon of glass-forming material at a plurality of locations of the ribbon of glass-forming material. The method may include identifying one or more of a position of the plurality of locations or a second position of the plurality of locations, wherein a corresponding thickness at the position exceeds a target thickness, wherein a second corresponding thickness at the second position is less than the target thickness. The method may include associating a thickness change rate and a thickness difference between the corresponding thickness and the target thickness with a laser power when the corresponding thickness at the position exceeds the target thickness. The method may include one or more of directing a laser beam toward the ribbon of glass-forming material at the laser power to reduce viscosity at the position and achieve a target thickness at the position, or directing a cooling fluid toward the ribbon of glass-forming material to increase viscosity at a second position and achieve a target thickness at the second position.

[0025] Additional features and advantages of the embodiments disclosed herein will be set forth in the following detailed description and will be partially apparent to those skilled in the art from this description or understood by practicing the embodiments described herein, including the subsequent detailed description, claims, and drawings. It should be understood that both the foregoing general description and the following detailed description present embodiments for the purpose of providing an overview or framework for understanding the nature and characteristics of the embodiments disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate various embodiments of the present invention and, together with the description, explain its principles and operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other features, embodiments, and advantages will be better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0027] Figure 1 Schematically illustrates an example embodiment of a glass manufacturing apparatus according to an embodiment of the present case;

[0028] Figure 2 According to the embodiment of the present invention, Figure 1 A cross-sectional view of a glass manufacturing apparatus along line 2-2;

[0029] Figure 3 A thickness sensor and control apparatus for glass manufacturing equipment for detecting and controlling the thickness of a ribbon of glass forming material is shown;

[0030] Figure 4 A thickness sensor is shown that detects the thickness of a first portion of a ribbon of glass forming material after the first portion is separated from a second portion;

[0031] Figure 5 A control scheme for sensing and controlling the thickness of a ribbon of glass forming material is shown;

[0032] Figure 6 A thickness sensor for detecting the thickness of a ribbon of glass forming material and a conditioning device for heating and / or cooling a portion of the ribbon of glass forming material are shown; and

[0033] Figure 7 A thickness sensor for detecting the thickness of a first portion of a ribbon of glass forming material after the first portion is separated from a second portion, and a conditioning device for heating and / or cooling a portion of the ribbon of glass forming material are shown. DETAILED DESCRIPTION

[0034] The embodiments will be described more fully below with reference to the accompanying drawings that illustrate example embodiments. In all drawings, the same reference numerals are used to refer to the same or similar parts as much as possible. However, the present invention can be implemented in many different forms and should not be interpreted as being limited to the embodiments set forth herein.

[0035] The present invention relates to a glass manufacturing apparatus and a method for producing a glass ribbon. The method and apparatus for producing a glass ribbon will now be described through exemplary embodiments, which are used to produce a glass ribbon from a glass forming material ribbon. Figure 1 As schematically shown in FIG. 1 , in some embodiments, an exemplary glass manufacturing apparatus 100 may include a glass melting and delivery apparatus 102, and a forming apparatus 101 including a forming vessel 140, the forming vessel 140 being designed to produce a ribbon of glass-forming material 103 from a quantity of molten material 121. In some embodiments, the ribbon of glass-forming material 103 may include a central portion 152 located between opposing edge portions (e.g., edge beads) formed along a first outer edge 153 and a second outer edge 155 of the ribbon of glass-forming material 103, wherein the thickness of the edge portions may be greater than the thickness of the central portion. Additionally, in some embodiments, the separated glass ribbon 104 may be separated from the ribbon of glass-forming material 103 along a separation path 151 by a glass separator 149 (e.g., a scribe, a scoring wheel, a diamond tip, a laser, etc.).

[0036] In some embodiments, the glass melting and delivery apparatus 102 may include a melting vessel 105 oriented to receive a batch material 107 from a storage tank 109. The batch material 107 may be introduced via a batch delivery device 111 powered by a motor 113. In some embodiments, an optional controller 115 may be operated to activate the motor 113 to introduce a desired amount of the batch material 107 into the melting vessel 105, as indicated by arrow 117. The melting vessel 105 may heat the batch material 107 to provide a molten material 121. In some embodiments, a melt probe 119 may be employed to measure the level of the molten material 121 within a standpipe 123, and the measured information may be communicated to the controller 115 via a communication line 125.

[0037] Additionally, in some embodiments, the glass melting and delivery apparatus 102 can include a first conditioning station including a fining vessel 127 located downstream of the melting vessel 105, and the fining vessel 127 is coupled to the melting vessel 105 via a first connecting conduit 129. In some embodiments, the molten material 121 can be gravity fed from the melting vessel 105 to the fining vessel 127 via the first connecting conduit 129. For example, in some embodiments, gravity can drive the molten material 121 from the melting vessel 105 to the fining vessel 127 through an internal path of the first connecting conduit 129. Additionally, in some embodiments, bubbles in the molten material 121 within the fining vessel 127 can be removed by various techniques.

[0038] In some embodiments, the glass melting and delivery apparatus 102 may further include a second conditioning station including a mixing chamber 131 that may be located downstream of the fining vessel 127. The mixing chamber 131 may be used to provide a uniform composition of the molten material 121, thereby reducing or eliminating non-uniformities that may otherwise exist within the molten material 121 exiting the fining vessel 127. As shown, the fining vessel 127 may be connected to the mixing chamber 131 via a second connecting conduit 135. In some embodiments, the molten material 121 may be gravity fed from the fining vessel 127 to the mixing chamber 131 via the second connecting conduit 135. For example, in some embodiments, gravity may drive the molten material 121 through the internal path of the second connecting conduit 135 from the fining vessel 127 to the mixing chamber 131.

[0039] Additionally, in some embodiments, the glass melting and delivery apparatus 102 can include a third conditioning station including a delivery chamber 133 that can be located downstream of the mixing chamber 131. In some embodiments, the delivery chamber 133 can condition the molten material 121 to feed it into the inlet conduit 141. For example, the delivery chamber 133 can act as an accumulator and / or a flow controller to condition and provide a consistent flow of the molten material 121 to the inlet conduit 141. As shown, the mixing chamber 131 can be coupled to the delivery chamber 133 via a third connecting conduit 137. In some embodiments, the molten material 121 can be gravity fed from the mixing chamber 131 to the delivery chamber 133 via the third connecting conduit 137. For example, in some embodiments, gravity can drive the molten material 121 through the internal path of the third connecting conduit 137 from the mixing chamber 131 to the delivery chamber 133. As further shown, in some embodiments, a delivery tube 139 can be positioned to deliver the molten material 121 to the inlet conduit 141 of the forming apparatus 101, such as the forming vessel 140.

[0040] The forming apparatus 101 may include various embodiments of forming vessels according to features of the present invention, such as a forming vessel having a wedge for melt-stretching a glass ribbon, a forming vessel having a slot for slot-stretching a glass ribbon, or a forming vessel having a roller for rolling a glass ribbon from a forming vessel. In some embodiments, the forming apparatus 101 may include sheet re-stretching, such as by the forming apparatus 101 as part of a re-stretching process. For example, a glass ribbon 104 that may include a thickness may be heated and then re-stretched to obtain a thinner glass ribbon 104 that includes a smaller thickness. As an illustration, a forming vessel 140 shown and disclosed below may be provided to melt-stretch a molten material 121 from a bottom edge (defined as a root 145) of a forming wedge 209 to produce a glass-forming material ribbon 103. For example, in some embodiments, the molten material 121 may be delivered to the forming vessel 140 from an inlet conduit 141. The molten material 121 may then be formed into a glass-forming material ribbon 103, depending in part on the structure of the forming vessel 140. For example, as shown, the molten material 121 can be pulled from a bottom edge (e.g., root 145) of the forming vessel 140 along a draw path extending in a direction of travel 154 of the glass manufacturing apparatus 100. In some embodiments, edge guides 163, 164 can direct the molten material 121 away from the forming vessel 140 and partially define a width "W" of the ribbon of glass forming material 103. In some embodiments, the width "W" of the ribbon of glass forming material 103 extends between a first outer edge 153 of the ribbon of glass forming material 103 and a second outer edge 155 of the ribbon of glass forming material 103.

[0041] In some embodiments, the width "W" of the glass forming material strip 103 extending between the first outer edge 153 of the glass forming material strip 103 and the second outer edge 155 of the glass forming material strip 103 can be greater than or equal to about 20 millimeters (mm), such as greater than or equal to about 50 mm, such as greater than or equal to about 100 mm, such as greater than or equal to about 500 mm, such as greater than or equal to about 1000 mm, such as greater than or equal to about 2000 mm, such as greater than or equal to about 3000 mm, such as greater than or equal to about 4000 mm, although other widths less than or greater than the above widths may be provided in other embodiments. For example, in some embodiments, the width "W" of the glass forming material ribbon 103 can be in the range of about 20 mm to about 4000 mm, such as in the range of about 50 mm to about 4000 mm, such as in the range of about 100 mm to about 4000 mm, such as in the range of about 500 mm to about 4000 mm, such as in the range of about 1000 mm to about 4000 mm, such as in the range of about 2000 mm to about 4000 mm, such as in the range of about 3000 mm to about 4000 mm. mm, for example in the range of about 20 mm to about 3000 mm, for example in the range of about 50 mm to about 3000 mm, for example in the range of about 100 mm to about 3000 mm, for example in the range of about 500 mm to about 3000 mm, for example in the range of about 1000 mm to about 3000 mm, for example in the range of about 2000 mm to about 3000 mm, for example in the range of about 2000 mm to about 2500 mm, and all ranges and sub-ranges therebetween.

[0042] Figure 2 Shown along Figure 1 2-2 of forming apparatus 101 (e.g., forming vessel 140). In some embodiments, forming vessel 140 may include trough 201 oriented to receive molten material 121 from inlet conduit 141. For purposes of illustration, for clarity, Figure 2 The cross-hatching of the molten material 121 is removed. The forming vessel 140 may also include a forming wedge 209, which includes opposite ends 210, 211 of the forming wedge 209 (see Figure 1140 ). The pair of downwardly inclined converging surface portions 207, 208 of the forming wedge 209 may converge along the travel direction 154 to intersect along the root 145 of the forming vessel 140. The root 145 defines a bottom of the forming wedge 209 where the downwardly inclined converging surface portions 207, 208 intersect to form a point. A stretching plane 213 of the glass manufacturing apparatus 100 may extend through the root 145 along the travel direction 154. In some embodiments, the glass forming material ribbon 103 may be stretched in the travel direction 154 along the stretching plane 213. As shown, the stretching plane 213 may bisect the forming wedge 209 through the root 145, although in some embodiments, the stretching plane 213 may extend in other directions relative to the root 145. In some embodiments, a method of manufacturing a glass ribbon can include moving the glass forming material ribbon 103 along a travel path 221 in a travel direction 154 , wherein the travel path 221 can be coplanar with the stretching plane 213 .

[0043] Additionally, in some embodiments, the molten material 121 may flow in the direction 156 and flow along the trough 201 of the forming vessel 140. The molten material 121 may then overflow from the trough 201 by simultaneously flowing over respective weirs 203, 204 and downwardly over the outer surfaces 205, 206 of the respective weirs 203, 204. For example, a method of making a glass ribbon may include flowing a first glass forming material stream 241 over a first weir 203 of a forming wedge 209 and flowing a second glass forming material stream 243 over a second weir 204 of the forming wedge 209. The first glass forming material stream 241 and the second glass forming material stream 243 may flow along the downwardly inclined converging surface portions 207, 208 of the forming wedge 209 to be pulled out of the root 145 of the forming vessel 140. In some embodiments, a method of making a glass ribbon may include fusing the first glass forming material stream 241 and the second glass forming material stream 243 to form a molten ribbon 245. For example, the first stream 241 and the second stream 243 may converge and fuse at the root 145. In some embodiments, a molten ribbon 245 may be pulled from the root 145 in the draw plane 213 along the travel direction 154. In some embodiments, the ribbon of glass-forming material 103 may include the first stream 241 and the second stream 243 of glass-forming material upstream of the root 145 relative to the travel direction 154 before fusing, and may include the molten ribbon 245 pulled from the root 145 downstream of the forming wedge 209 relative to the travel direction 154. Depending on the vertical position of the ribbon of glass-forming material 103, the ribbon of glass-forming material 103 may include at least one material state. For example, at one position, the ribbon of glass-forming material 103 may include a viscous molten material 121, while at another position, the ribbon of glass-forming material 103 may include a glassy amorphous solid (e.g., a glass ribbon).

[0044] The ribbon of glass forming material 103 includes a first major surface 215 and a second major surface 216 that face in opposite directions and define a thickness "T" (e.g., an average thickness) of the ribbon of glass forming material 103 along an axis that is perpendicular to one or both of the first major surface 215 or the second major surface 216. In some embodiments, the thickness "T" of the ribbon of glass forming material 103 can be less than or equal to about 2 millimeters (mm), less than or equal to about 1 mm, less than or equal to about 0.5 mm, e.g., less than or equal to about 300 micrometers (μm), less than or equal to about 200 μm, or less than or equal to about 100 μm, although other thicknesses can be provided in further embodiments. For example, in some embodiments, the thickness "T" of the glass forming material ribbon 103 can be in the range of about 20 microns to about 200 microns, in the range of about 50 microns to about 750 microns, in the range of about 100 microns to about 700 microns, in the range of about 200 microns to about 600 microns, in the range of about 300 microns to about 500 microns, in the range of about 50 microns to about 500 microns, in the range of about 50 microns to about 700 microns, in the range of about 50 microns to about 600 microns, in the range of about 50 microns to about 500 microns, in the range of about 50 microns to about 400 microns, in the range of about 50 microns to about 300 microns, in the range of about 50 microns to about 200 microns, in the range of about 50 microns to about 100 microns, in the range of about 25 microns to about 125 microns, including all thickness ranges and sub-ranges therebetween. Additionally, the glass forming material ribbon 103 may include a variety of compositions, such as borosilicate glass, aluminoborosilicate glass, alkali-containing glass, or alkali-free glass, alkali aluminosilicate glass, alkaline earth aluminosilicate glass, soda-lime glass, and the like.

[0045] In some embodiments, the glass separator 149 (see Figure 1 ) The glass ribbon 104 can be separated from the glass forming material ribbon 103 along a separation path 151 to provide a plurality of separated glass ribbons 104 (i.e., a plurality of glass sheets). According to other embodiments, a longer portion of the glass ribbon 104 can be wound onto a storage roll. The separated glass ribbon can then be processed into a desired application, such as a display application. For example, the separated glass ribbon can be used in a variety of display applications, including liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), touch sensors, optoelectronic and other electronic displays.

[0046] Figure 31 shows a schematic diagram of a forming vessel 140. In some embodiments, the glass manufacturing apparatus 100 may include a thickness sensor 301 that can measure the thickness of the glass forming material ribbon 103 (e.g., Figure 2 For example, the thickness between the first major surface 215 and the second major surface 216 of the ribbon of glass forming material 103 (e.g., perpendicular to the Figure 1 154). In some embodiments, thickness sensor 301 can detect the thickness of the ribbon of glass forming material 103 at the bottom of forming vessel 140 (e.g., downstream of root 145 of forming vessel 140 relative to direction of travel 154). In some embodiments, thickness sensor 301 can include a laser-based thickness measurement device.

[0047] In some embodiments, the thickness sensor 301 can detect the thickness of the ribbon of glass forming material 103 at one or more locations, such as at a first location 303, a second location 305, a third location 307, a fourth location 309, etc. In some embodiments, a method of manufacturing a glass ribbon can include detecting the thickness of the ribbon of glass forming material 103 at a plurality of locations (e.g., the first location 303, the second location 305, the third location 307, the fourth location 309, etc.). Detecting the thickness of the ribbon of glass forming material 103 can be performed at a plurality of locations spaced apart along a first axis 313, which can be substantially perpendicular to the direction of travel 154. For example, the first axis 313 can extend across the ribbon of glass forming material 103 (e.g., between the first outer edge 153 and the second outer edge 155) in a direction substantially parallel to the first major surface 215 and / or the second major surface 216 of the ribbon of glass forming material 103. In some embodiments, the distance separating the first position 303 from the first outer edge 153 may be less than the distance separating the second position 305, the third position 307, and / or the fourth position 309 from the first outer edge 153. In some embodiments, the distance separating the fourth position 309 from the second outer edge 155 may be less than the distance separating the first position 303, the second position 305, and / or the third position 307 from the second outer edge 155. In some embodiments, the second position 305 and the third position 307 may be located between the first position 303 and the fourth position 309.

[0048] Glass manufacturing apparatus 100 is not limited to detecting the thickness of glass forming material ribbon 103 along a single axis, such as first axis 313. Rather, in some embodiments, thickness sensor 301 and / or additional thickness sensors may detect the thickness of glass forming material ribbon 103 along one or more axes that are angled relative to first axis 313, such as along second axis 315 that may be substantially perpendicular to first axis 313 and substantially parallel to direction of travel 154. Second axis 315 may intersect second location 305. In some embodiments, thickness sensor 301 and / or additional thickness sensors may detect the thickness of glass forming material ribbon 103 along one or more axes that are substantially parallel to first axis 313 and / or second axis 315.

[0049] In some embodiments, the thickness sensor 301 may generate a thickness profile 321 corresponding to the thickness detected by the thickness sensor 301 at multiple locations, such as the first location 303, the second location 305, the third location 307, and the fourth location 309. The thickness sensor 301 may periodically and / or continuously detect the thickness of the glass forming material ribbon 103. For example, in some embodiments, the thickness sensor 301 may continuously (e.g., without interruptions or gaps) detect the thickness at multiple locations, so that the thickness sensor 301 can generate an updated thickness profile 321 corresponding to the real-time thickness of the glass forming material ribbon 103. The real-time thickness of the glass forming material ribbon 103 may represent the thickness at the moment when the glass forming material ribbon 103 is measured, so the thickness of the glass forming material ribbon 103 can be immediately transmitted to a device (e.g., the control device 325) for processing. In some embodiments, the thickness sensor 301 may periodically detect the thickness at multiple locations, such as by detecting the thickness of the glass forming material ribbon 103, then waiting for a predetermined time without detecting the thickness, then detecting the thickness again, and so on. The thickness sensor 301 can thus generate an updated thickness profile 321 that may not correspond to the real-time thickness at the plurality of locations. In some embodiments, the thickness sensor 301 can detect thickness at a static position relative to the formed vessel 140. For example, in some embodiments, the thickness sensor 301 can detect thickness at the plurality of locations 303, 305, 307, or 309, wherein the first axis 313 and the plurality of locations 303, 305, 307, or 309 can thus be located at a static and unchanging distance from the root 145.

[0050] In some embodiments, the glass manufacturing apparatus 100 may include a control device 325 that may be coupled to the thickness sensor 301. The control device 325 may include, for example, a computer, a computer-like device, a programmable logic controller, etc. In some embodiments, the control device 325 may be configured (e.g., programmed, coded, designed, and / or made) to implement a change in the thickness of the glass forming material strip 103 based on the thickness detected by the thickness sensor 301. For example, the thickness sensor 301 may communicate with the control device 325 via a communication link 327 (e.g., wired, wireless, etc.). The thickness profile 321 may be transmitted from the thickness sensor 301 to the control device 325 via the communication link 327. In some embodiments, a target thickness profile 331 may be transmitted to the control device 325. The target thickness profile 331 may include an operating range for a target thickness of the glass forming material strip 103. For example, target thickness profile 331 may include a first target thickness at first location 303 , a second target thickness at second location 305 , a third target thickness at third location 307 , and a fourth target thickness at fourth location 309 .

[0051] In some embodiments, the glass manufacturing apparatus 100 may include a laser device 335 that may emit a laser beam to increase the temperature and reduce the viscosity of a portion of the glass forming material ribbon 103 in a viscous state, thereby changing the thickness of the portion of the glass forming material ribbon 103 struck by the laser beam. In some embodiments, the laser device 335 may include a laser generator 337. The laser generator 337 may generate and emit a laser beam. In some embodiments, the laser generator 337 may include a high-intensity infrared laser generator, such as a carbon dioxide (CO2) laser generator. The laser generator 337 may generate a laser beam having a wavelength and power sufficient to increase the temperature and reduce the viscosity of the portion of the glass forming material ribbon 103 struck by the laser beam. In some embodiments, in order to control the orientation of the laser beam from the laser generator 337, the laser device 335 may include a beam guiding device 339. The beam guiding device 339 may include a reflective surface, such as a mirror. Beam directing device 339 may be coupled to a mobile device, which may move beam directing device 339 , for example, by rotating beam directing device 339 and / or translating beam directing device 339 .

[0052] The beam directing device 339 can receive the laser beam from the laser generator 337 and direct the laser beam (e.g., reflect when the beam directing device 339 includes a mirror) toward the ribbon of glass forming material 103. For example, in some embodiments, the beam directing device 339 can direct the laser beam toward one or more of the first position 303, the second position 305, the third position 307, and / or the fourth position 309. In some embodiments, the beam directing device 339 can direct the first laser beam 351 toward the first position 303, wherein the first laser beam 351 can impinge on the ribbon of glass forming material 103 at a position below the root 145 of the forming vessel 140. In some embodiments, the beam directing device 339 can direct the second laser beam 353 toward the second position 305, wherein the second laser beam 353 can impinge on the ribbon of glass forming material 103 at a position below the root 145 of the forming vessel 140. In some embodiments, beam directing device 339 may direct third laser beam 355 toward third location 307, wherein third laser beam 355 may impinge on ribbon of glass forming material 103 at a location below root 145 of forming vessel 140. In some embodiments, beam directing device 339 may direct fourth laser beam 357 toward fourth location 309, wherein fourth laser beam 357 may impinge on ribbon of glass forming material 103 at a location below root 145 of forming vessel 140. In some embodiments, beam directing device 339 may be moved according to control instructions that may be provided to laser device 335 from control device 325, wherein the control instructions may instruct beam directing device 339 to direct one or more laser beams 351, 353, 355, or 357 toward a particular location.

[0053] The beam directing device 339 is not limited to reflecting the laser beam toward a position below the root 145 of the forming vessel 140 relative to the direction of travel 154, but in some embodiments, the beam directing device 339 can direct the laser beam above the root 145 toward, for example, the first weir 203 and / or the second weir 204. In some embodiments, the beam directing device 339 can direct the first laser beam 361 toward the first weir 203 and / or the second weir 204 at a position corresponding to the first position 303. As used herein, a position corresponding to the first position 303 may include a position of the first glass forming material stream 241 and / or the second glass forming material stream 243 upstream of the first position 303 relative to the direction of travel 154 when the first stream 241 and / or the second stream 243 exit the forming vessel 140 intersecting the first position 303. In some embodiments, the beam directing device 339 can direct the second laser beam 363 toward the first weir 203 and / or the second weir 204 at a position corresponding to the second position 305. In some embodiments, beam directing device 339 can direct third laser beam 365 toward first weir 203 and / or second weir 204 at a position corresponding to third position 305. In some embodiments, beam directing device 339 can direct fourth laser beam 367 toward first weir 203 and / or second weir 204 at a position corresponding to fourth position 309.

[0054] In some embodiments, the control device 325 may compare the thickness profile 321 to the target thickness profile 331 to determine whether the corresponding thickness at one of the positions 303, 305, 307, or 309 exceeds the target thickness of the target thickness profile 331. For example, the control device 325 may receive the thickness profile 321, which may include the thickness of the glass forming material ribbon 103 measured by the thickness sensor 301 at the first position 303, the second position 305, the third position 307, and the fourth position 309. The control device 325 may compare the thickness at the positions 303, 305, 307, and / or 309 to the target thickness profile 331, such as comparing the target thickness of the positions 303, 305, 307, and / or 309, respectively. In some embodiments, the method of manufacturing a glass ribbon may include identifying a position at the plurality of positions 303, 305, 307, and / or 309 where the corresponding thickness at the position exceeds the target thickness (e.g., according to the target thickness profile 331). The control device 325 can determine the thickness difference between the measured thickness at one of the locations 303, 305, 307, or 309 and the target thickness at the location 303, 305, 307, or 309. Figure 5As described, control device 325 can determine the appropriate laser power of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 to cause a viscosity reduction at the location and achieve a target thickness at the location.

[0055] The control device 325 can transmit instructions including appropriate laser power and position to the laser device 335. In some embodiments, the method of manufacturing a glass ribbon can include directing a laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 toward the ribbon of glass forming material 103 to reduce viscosity at the location and achieve a target thickness at the location. For example, in some embodiments, the measured thickness at the first location 303 of the ribbon of glass forming material 103 can exceed the target thickness at the first location 303. The control device 325 can determine the difference between the measured thickness at the first location 303 and the target thickness and relate the rate of change of thickness to the laser power. In some embodiments, the rate of change of thickness and the laser power can be provided to the control device 325 and can be based on actual observed effects of thickness changes based on a particular laser power. In some embodiments, the rate of change of thickness and the laser power provided to the control device 325 can be based on a mathematical model. In some embodiments, the model can be updated with actual observed impacts based on different laser powers. Control device 325 may cause laser generator 337 to direct first laser beam 351 at laser power toward first location 303. In response, viscosity at first location 303 may decrease, which may cause thickness at first location 303 to decrease until a target thickness is reached at first location 303. In some embodiments, a method of manufacturing a glass ribbon may include directing laser beams 361, 363, 365, and / or 367 toward one or more of first glass-forming material flow 241 flowing through first weir 203, second glass-forming material flow 243 flowing through second weir 204, or molten ribbon 245. For example, control device 325 may trigger laser generator 337 to direct first laser beam 361 toward first glass-forming material flow 241 flowing through first weir 203 and / or toward second glass-forming material flow 243 flowing through second weir 204. The viscosity of the first glass forming material stream 241 or the second glass forming material stream 243 may decrease, which may cause the thickness at the first location 303 to decrease until a target thickness is reached at the first location 303 .

[0056] Reference Figure 4In some embodiments, the thickness of ribbon of glass forming material 103 may be detected after first ribbon portion 401 has been separated from second ribbon portion 403. For example, in some embodiments, a method of manufacturing a glass ribbon may include separating first ribbon portion 401 of ribbon of glass forming material 103 from second ribbon portion 403 of ribbon of glass forming material 103 before detecting the thickness of first ribbon portion 401. As ribbon of glass forming material 103 moves along travel direction 154, first ribbon portion 401 may be separated from second ribbon portion 403, for example, by Figure 1 The first tape portion 401 is separated from the second tape portion 403 by the glass separator 149. In some embodiments, the first tape portion 401 can be transported to a remote location after separation, for example, to a location where the first tape portion 401 can be inspected and the thickness can be measured.

[0057] After separation, the method of manufacturing a glass ribbon can include detecting the thickness at multiple locations of the first ribbon portion 401. For example, the thickness sensor 301 can detect the thickness of the first ribbon portion 401 at a first location 411, a second location 413, a third location 415, and a fourth location 417 of the first ribbon portion 401, although in other embodiments, the thickness at more than four locations can be detected, and in other embodiments, the thickness at less than four locations can be detected. In some embodiments, after separating the first ribbon portion 401 of the ribbon of glass forming material 103 from the second ribbon portion 403, the thickness of the ribbon of glass forming material 103 can be detected in the first ribbon portion 401 of the ribbon of glass forming material 103. In some embodiments, the thickness of the first ribbon portion 401 can be detected immediately after the first ribbon portion 401 is separated from the second ribbon portion 403, so that the time delay between the separation of the first ribbon portion 401 and the detection of the thickness of the first ribbon portion 401 can be brief. In some embodiments, the time delay may be longer, for example, when the thickness of first belt portion 401 is detected not immediately after separation, but some time after separation. For example, the time delay may result when first belt portion 401 is transported from the location where first belt portion 401 is separated to a remote location where first belt portion 401 can be inspected and the thickness can be measured.

[0058] In some embodiments, the positions of first position 411, second position 413, third position 415, and / or fourth position 417 relative to first outer edge 153 and second outer edge 155 of first band portion 401 may correspond to the positions of first position 303, second position 305, third position 307, and / or fourth position 309, respectively, relative to first outer edge 153 and second outer edge 155 of second band portion 403. For example, first position 411 may be spaced a first distance from first outer edge 153 of first band portion 401, and first position 303 may be spaced a first distance from first outer edge 153 of second band portion 403. In some embodiments, fourth position 417 may be spaced a second distance from second outer edge 155 of first band portion 401, and fourth position 309 may be spaced a second distance from second outer edge 155 of second band portion 403. In some embodiments, the distance separating the plurality of locations 411, 413, 415, or 417 of the first tape portion 401 can match the distance separating the plurality of locations 303, 305, 307, or 309 of the second tape portion 403. Thus, the thickness at the plurality of locations 411, 413, 415, or 417 of the first tape portion 401 can be varied by impinging the laser beam 351, 353, 355, or 357 at the plurality of locations 303, 305, 307, or 309 of the second tape portion 403 and / or by impinging the laser beam 361, 363, 365, or 367 at the first stream 241 flowing over the first weir 203 and / or the second stream 243 flowing over the second weir 204.

[0059] In some embodiments, the method of manufacturing a glass ribbon may include identifying a first position in a plurality of positions 411, 413, 415, or 417, wherein the corresponding thickness at the first position 303 exceeds the target thickness. For example, in some embodiments, Figure 4 The glass manufacturing apparatus 100 in the embodiment may include a thickness sensor 301, a control device 325, and a laser device 335, which may be substantially similar to Figure 3The invention relates to a thickness sensor 301, a control device 325, and a laser device 335. The thickness sensor 301 can detect the thickness at multiple locations 411, 413, 415, or 417 of the first belt portion 401 and generate a thickness profile 321. In some embodiments, the control device 325 can compare the thickness of the measured thickness profile 321 with the target thickness profile 331 to identify whether any measured thickness at the location 411, 413, 415, or 417 exceeds the target thickness. In addition, in some embodiments, the control device 325 can calculate the time delay between the separation of the first belt portion 401 (e.g., from the second belt portion 403) and the thickness detection. For example, a period of time can pass between the separation of the first belt portion 401 and the detection of the thickness at the location 411, 413, 415, or 417 with the thickness sensor 301, wherein this period of time can partially include the time required to transport the first belt portion 401 to a remote location.

[0060] In some embodiments, a method of manufacturing a glass ribbon may include directing a laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 at a laser power according to a time delay to a second location 303, 305, 307, and / or 309 of a second ribbon portion 403 corresponding to a first location 411, 413, 415, and / or 417 of a first ribbon portion 401, respectively, to reduce viscosity at the second location 303, 305, 307, and / or 309 and achieve a target thickness at the second location 303, 305, 307, and / or 309. In some embodiments, the laser device 335 may be similar to Figure 3 In some embodiments, laser device 335 may direct one or more of laser beams 351, 353, 355, 357, 361, 363, 365, 367 toward ribbon of glass-forming material 103. For example, in some embodiments, laser device 335 may direct one or more of laser beams 361, 363, 365, or 367 toward first stream 241 of glass-forming material on first weir 203 or toward one or more of second stream 243 of glass-forming material on second weir 204. In some embodiments, laser device 335 may direct one or more of laser beams 351, 353, 355, or 357 toward molten ribbon 245.

[0061] In some embodiments, the effects of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 may not be immediately detectable by thickness sensor 301 due to a time delay between separation of first tape portion 401 from second tape portion 403 and detection of the thickness of first tape portion 401. For example, in Figure 3In the embodiment of the present invention, wherein thickness sensor 301 may be located near and downstream of position 303, 305, 307, and / or 309 relative to direction of travel 154, thickness changes caused by laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 after impacting ribbon 103 of glass forming material, may be detected quickly by thickness sensor 301. However, in the embodiment of the present invention, thickness sensor 301 may be located near and downstream of position 303, 305, 307, and / or 309 relative to direction of travel 154. Figure 4 325 , the time delay caused by the separation of the first tape portion 401 may result in a time delay between when the laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 impinges on the second tape portion 403 and when the thickness sensor 301 detects the resulting thickness change. Thus, in some embodiments, the control device 325 may incorporate the time delay into the instructions transmitted to the laser device 335. For example, in the absence of the control device 325 incorporating the time delay, the laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 may be directed to impinge on the second tape portion 403 at a power and / or for a time greater than that required to achieve the target thickness change, thereby resulting in a thickness change exceeding the target thickness profile 331.

[0062] In some embodiments, in order to direct the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 at appropriate laser powers in accordance with the time delay, a time delay profile 431 may be transmitted to the control device 325. For example, the time delay profile 431 may include the amount of time that has elapsed between separation of the first tape portion 401 and the second tape portion 403 and the thickness detection of the first tape portion 401, and / or the amount of time that has elapsed between impinging the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 on the second tape portion 403 and the subsequent thickness detection of the second tape portion 403. In some embodiments, the amount of time that has elapsed may include actual observed time, such as time measured by a timing device. In some embodiments, the amount of time that has elapsed can be provided based on a mathematical model, such as one or both of a predicted amount of time that has elapsed (e.g., between separation or impact and detection) or an average amount of time that has elapsed (e.g., between separation or impact and detection) over one or more cycles. Providing a time delay profile 431 to the control device 325 may be beneficial for a number of reasons. For example, the time delay may represent an amount of time between when the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 are directed toward the ribbon of glass forming material 103 (e.g., which may increase the temperature and decrease the viscosity at a location of the ribbon of glass forming material 103, thereby changing the thickness at that location) and when the resulting change in thickness is detected by the thickness sensor 301. Reference Figure 3 Since the thickness sensor 301 detects the thickness at a position very close to the location where the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinge on the glass forming material ribbon 103, the time delay is negligible, so that the thickness sensor 301 can detect the thickness change almost immediately after the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 are applied. Figure 4 , the time delay between separation of first ribbon portion 401 and thickness detection by thickness sensor 301 increases the time between when laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinge on ribbon of glass forming material 103 and when thickness sensor 301 can detect the resulting thickness change in first ribbon portion 401. Thus, by incorporating time delay profile 431, control device 325 can achieve more accurate thickness changes and limit the likelihood of exceeding target thickness profile 331.

[0063] refer to Figure 5, schematic flow chart 501 illustrates a method for manufacturing a glass ribbon using control device 325. In some embodiments, control device 325 can consider the effect of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 on the magnitude of the change in thickness of glass-forming material ribbon 103 and the speed of the thickness change. For example, the impact of laser device 335 on glass-forming material ribbon 103 can be modeled using a gain matrix that relates the power of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 to the thickness change at a location on glass-forming material ribbon 103. In some embodiments, by modeling the impact of laser device 335 with a gain matrix, the thickness variation caused by laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 at the location where laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impact the ribbon of glass forming material 103, as well as the thickness variation at surrounding locations not impacted by laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367, can be modeled. The gain matrix can be represented by the variable K mxp , and may have dimensions mxp, where m is a variable representing the total number of positions (e.g., Figure 3 Positions 303, 305, 307, and / or 309 in Figure 4 411, 413, 415, and / or 417) at which the thickness is measured by thickness sensor 301. Variable p may represent the total number of positions (e.g., Figure 3 and Figure 4 303, 305, 307, and / or 309 in FIG. 304 at which laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinge on ribbon 103 of glass forming material. In some embodiments, variable p may incorporate the area of ​​laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinging on ribbon 103 of glass forming material, the resolution of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 as determined by beam directing apparatus 339, and the speed at which laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 are moved across ribbon 103 of glass forming material (e.g., as moved by beam directing apparatus 339).

[0064] In some embodiments, the response to a change in the power of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 may be modeled. For example, a process model may be developed that relates the laser power of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 to a change in thickness at a location of ribbon of glass forming material 103, and to a time delay between the application of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 and the achievement of the change in thickness. In some embodiments, if the control device 325 identifies one or more of the plurality of locations 303, 305, 307, or 309 as including a thickness that exceeds a target thickness, the control device 325 may determine an appropriate laser power for the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 and direct the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 toward the ribbon of glass forming material 103. For example, in some embodiments, the process model may include a thickness profile that identifies the impact of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 at locations adjacent to the locations where the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impact on the ribbon of glass forming material 103. For example, refer to Figure 3 to Figure 4 , if the second laser beam 353 impinges on the second location 305, the process model may include a thickness profile of the thickness of the second location 305 and adjacent locations (e.g., the first location 303, the third location 307, etc.) that may also experience thickness changes. In some embodiments, the dynamic process model may be obtained by one or more of first principles or empirical modeling using experimental data. For example, using empirical modeling methods, the power of the laser beams 351, 353, 355, 357, 361, 363, 365, 367 may be synchronized with the output (e.g., the thickness profile of the glass forming material ribbon 103) modeled for each laser power. The model may be represented by equations (1) and (2) as follows:

[0065] (1)

[0066] (2) y(t)=C c x c (t-θ)

[0067] In equations (1) and (2), variable t is a time variable expressed in seconds, and variable θ is a time delay (e.g., dead time) expressed in seconds. In some embodiments, time delay θ may represent the amount of time that a process (e.g., the thickness of glass forming material ribbon 103) will begin to change in response to the impact of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367. For example, referring to Figure 4 , the time delay θ may represent the amount of time between the impact of the laser beams 351 , 353 , 355 , 357 , 361 , 363 , 365 , and / or 367 and the thickness detected by the thickness sensor 301 . The variable is a state vector and may represent a vector of thickness positions at different locations across the ribbon of glass forming material 103, for example, Figure 3 Position 303, 305, 307, or 309 in the example, and / or Figure 4 The variable y is the output and may represent a vector at the measured thickness location, for example, Figure 3 The thickness of the position 303, 305, 307, or 309 in the embodiment, and / or Figure 4 In some embodiments, the variables y and The same data may be included separated in time by a time delay θ. The variable u is an input and may represent a vector at different locations where the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 are applied at a laser power, for example, due to being impacted by the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367.

[0068] The system matrix can then be expressed by equations (3), (4), and (5) as follows:

[0069] (3)

[0070] (4) B c =-A c K [mxp]

[0071] (5) C c =I mxm

[0072] In equations (3) and (5), the variable I is an mxm identity matrix. In equation (4), the variable K mxp The gain matrix may be represented by , and may have dimensions of mxp, where m is a location where the thickness may be measured by the thickness sensor 301 (eg, Figure 3 Position 303, 305, 307, or 309 in the example, and / or Figure 4 The variable p may represent the total number of positions (e.g., Figures 3 to 4 303, 305, 307, or 309) at which laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinge on ribbon 103 of glass forming material. Thus, this model (e.g., represented by equations (1) and (2)) can be converted to a discrete time-space form using standard discretization techniques represented by equations (6) and (7), as follows:

[0073] (6) x m (k+1)=A m x m (k)+B m u(k)

[0074] (7) y m (k) = C m x m (k-θ)

[0075] In equations (6) and (7), the variable k is the discrete time step. Figure 4 , the discrete time step k may be the product of the process cycle time when the thickness of first ribbon portion 401 is measured by thickness sensor 301 after first ribbon portion 401 is separated from second ribbon portion 403. For example, a period of time (e.g., process cycle time) may elapse between a location of ribbon 103 of glass forming material where laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 is struck and a location where thickness is measured, for example, where separation and transportation of the first ribbon portion may occur between the impact of laser beam 351, 353, 355, 357, 361, 363, 365, and / or 367 and the thickness is measured. In some embodiments, reference is made to Figure 3 , when the thickness of glass forming material ribbon 103 is measured by thickness sensor 301 before separation, discrete time step k may be shorter. For example, since thickness sensor 301 detects the thickness at position 303, 305, 307, or 309 immediately adjacent to the position where laser beam 351, 353, 355, 357, 361, 363, 365, 367 strikes glass forming material ribbon 103, discrete time step k may be shorter.

[0076] In some embodiments, the control device 325 can account for disturbances that affect the thickness of the glass forming material ribbon 103, such as Figure 2In some embodiments, the control device 325 may include a model predictive control to control the thickness of the ribbon of glass forming material 103 while satisfying one or more constraints, such as the laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367. In addition or alternatively, in some embodiments, the control device 325 may consider constraints on the laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 so as not to exceed the maximum laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367. To consider these disturbances and laser power constraints, the control device 325 may include a model predictive control. The model predictive control may control the thickness of the ribbon of glass forming material 103 while satisfying one or more constraints, such as the laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367. In some embodiments, the model predictive control can simulate the future thickness of the ribbon of glass forming material 103 and calculate the action of the laser device 335, such as the laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367, and the location where the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 strike the ribbon of glass forming material 103. Thus, the model predictive control can achieve a target thickness profile for the ribbon of glass forming material 103 and maintain the target thickness profile regardless of disturbances (e.g., Figure 2 In some embodiments, the model predictive control may include a delay compensation scheme, such as a Smithpredictor, to account for the time delay θ and the discrete time step k. For example, the control device 325 may include a delay-free model predictive control 503 based on discrete time-space equations (6) and (7). The delay-free model predictive control 503 can predict the future behavior of the program, for example, predicting the thickness of the glass forming material ribbon 103 at a certain time in the future. The delay-free model predictive control 503 can receive a set point 502 or a reference function, which can include a target thickness range for different positions 303, 305, 307, and / or 309 of the glass forming material ribbon 103. In some embodiments, based on the predicted future behavior, the delay-free model predictive control 503 can optimize the action of the laser device 335 (e.g., laser power, impact location, etc.). The delay-free model predictive control 503 can be expressed by equations (8) and (9) as follows:

[0077] (8) x(k+1)=Ax(k)+Bu(k)

[0078] (9) y(k)=Cx(k)

[0079] In some embodiments, the delay-free model predictive control 503 can be designed in part by setting target thickness profiles for the positions 303, 305, 307, and / or 309 of the ribbon of glass forming material 103 at a future time period. In some embodiments, the target thickness profiles for the positions 303, 305, 307, and / or 309 can be provided to the control device 325 as part of the target thickness profile 331. For example, a first target thickness range can be set for the first position 303, a second target thickness range can be set for the second position 305, a third target thickness range can be set for the third position 307, and a fourth target thickness range can be set for the fourth position 309. The target thickness ranges can be represented by the variable S in the following equation (10). The variable S can represent a matrix, where each column of the matrix S includes one of the target thickness ranges and each row of the matrix S includes the target thickness ranges at a future time period. For example, a column may include a target thickness range at a first position 303 over a period of time, and a row may include a target thickness range at the first position 303 at a first time, an adjacent row may include a target thickness range at the first position 303 at a second time after the first time, etc. In addition, the variable X in equation (10) may represent a matrix of detected thicknesses (e.g., as detected by thickness sensor 301). In some embodiments, the variable X may represent a matrix, wherein each column of the matrix X may include a detected thickness at one of positions 303, 305, 307, or 309, and each row of the matrix X may include simulated thicknesses at a future period of time in accordance with equations (8) and (9). For example, a column may include a detected thickness at a first position 303 over a period of time, wherein a row may include a detected thickness at the first position 303 at a first time, an adjacent row may include a detected thickness at the first position 303 at a second time, etc. The quadratic cost function J may be represented by the following equation (10):

[0080] (10) J=(SX) T Q(SX)+U T RU

[0081] (11) f(U)≤C

[0082] In equation (10), variables Q and R represent weighting matrices that can penalize deviations between the detected thickness and the target thickness, e.g., when the detected thickness (e.g., represented by matrix X) is different from the target thickness (e.g., represented by matrix S), and the efficacy of the laser power (e.g., represented by matrix U), respectively. For example, variable Q penalizes deviations between the detected thickness and the target thickness, while variable R penalizes the amount of power used to drive the thickness to the target thickness. In equations (10) and (11), variable U can represent a set of laser power shifts. For example, variable U can represent a matrix in which each column can include laser power at one of positions 303, 305, 307, or 309, and each row of variable U can include laser power at a future time period (e.g., the first row can include laser power at discrete time step k, the second row can include laser power at discrete time step k+1, etc.). In some embodiments, as shown in equation (11), the variable U can be selected to minimize the quadratic cost function J, for example, the laser power (e.g., variable U) is within a range from about zero to the maximum laser power rating of the laser device 335. Equation (11) provides upper and lower limits on the amount of power delivered to the laser. The algorithm can be optimized to find the matrix U that minimizes J, thereby satisfying equations (8), (9), and (10). Therefore, the delay-free model predictive control 503 can determine the appropriate laser power of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 that does not exceed the maximum laser power rating, but is strong enough to cause a thickness change within a predetermined time. Therefore, the delay-free model predictive control 503 can control the laser power and position of the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 at each discrete time step k. In this manner, in some embodiments, a method of manufacturing a glass ribbon may include, for example, associating a rate of change of thickness and a thickness difference between a corresponding thickness and a target thickness with a laser power when a corresponding thickness at a location exceeds a target thickness. For example, the weighting matrix (e.g., Q and R) of equation (10) may penalize a thickness difference (e.g., a deviation between a detected thickness and a target thickness), and the variable R may penalize the efficacy of the laser power, while the laser power shift represented by U may include the laser power applied at the location 303, 305, 307, or 309 in the future. In some embodiments, selecting a larger variable R may cause the algorithm to use a smaller laser power shift for each sampling moment k. In some embodiments, a larger variable R may be used to avoid larger and / or faster laser power shifts. Similarly, selecting a smaller variable R may cause the algorithm to use a larger laser power shift for each sampling moment k, thereby facilitating larger and faster laser power shifts to reach the target thickness.The thickness variation rate can be expressed by equations (1) and (2), where the output y can represent a vector at the measured thickness location and can therefore represent the thickness variation rate in response to an input μ (e.g., a laser beam applied at a laser power at a location).

[0083] In some embodiments, the control device 325 can perform model simulation 505 based on the delay-free model predictive control 503. For example, the model simulation 505 can predict program behavior and simulate the state vector x(k) of equation (8) based on the delay-free model predictive control 503. In some embodiments, the model simulation 505 can generate a delay-free predicted state vector 506, which can be represented by x(k). The delay-free predicted state vector 506 can represent the predicted thickness of the glass forming material ribbon 103 at a location one or more discrete time steps k in the future. In some embodiments, to solve Figure 4 The undelayed predicted state vector 506 (e.g., x(k)) is then subjected to a time delay 509 (e.g., time delay θ) to produce a delayed state 510, e.g., x(k). d (k-θ). In some embodiments, the actual thickness detected by the thickness sensor 301 at discrete time k (e.g., a measured state vector) can be represented by a program including a time delay 507, which can generate a time-delayed complete system state 508 (e.g., including the actual thickness detected by the thickness sensor 301, the time delay θ, and any potential program interference). The time-delayed complete system state 508 (e.g., the measured state vector) can be represented by x m In some embodiments, the measured state vector 508 (e.g., x m (k-θ)) and the predicted state vector 510 (e.g., x) including the time delay 509 d (k-θ)) are compared 511, and the result can be expressed by the following equation (12):

[0084] (12) x e (k) = x m (k-θ)-x d (k-θ)

[0085] The difference x e (k) is the delayed state prediction error, which represents the difference between the detected thickness (e.g., from thickness sensor 301) and the predicted thickness. In some embodiments, the error may be caused by disturbances in model simulation 505 (e.g., Figure 2 If the predicted state vector includes the vectors from 509 (e.g., x d (k-θ)) matches exactly the time delay from 507 (e.g., x m (k-θ)) is the measured state vector, then the delayed state prediction error x e (k) can be zero. However, if the d The predicted state vector of the time delay (k-θ)) is different from the state vector from 507 (e.g., x m (k-θ)), the delayed state prediction error may be non-zero and may be filtered by filter 513 (e.g., to filter out certain frequency ranges). In some embodiments, filter 513 may produce a filtered delayed state prediction error 521, which may be represented by x f The filtered delayed state prediction error 521 can be added to the undelayed predicted state vector 506 (e.g., x(k)) to produce a corrected state vector 527, which can be represented by Corrected state vector 527 may include feedback that may be received by no-delay model predictive control 503. Thus, no-delay model predictive control 503 may receive set point 502 and corrected state vector 527 and adjust laser device 335 to bring the thickness of glass forming material ribbon 103 closer to set point 502.

[0086] In some embodiments, Figure 4 The control device 325 may include Figure 5 In the control scheme, there is a large time delay between the impact of laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 on ribbon 103 of glass-forming material and the detection of the thickness of first ribbon portion 401 after the separation of first ribbon portion 401 from second ribbon portion 403. For example, Figure 5 The control scheme may include a Smith Predictor that incorporates model simulation 505 to produce a predicted state vector 506 without delay, which is then subjected to a time delay 509 and compared to the measured state vector 508. In some embodiments, the time delay may be less than Figure 4 For example, refer to Figure 3, when thickness sensor 301 is configured to detect thickness at a location close to where laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 impinge on ribbon 103 of glass forming material (e.g., where both thickness detection and laser beam impingement occur before first ribbon portion 401 separates), this time delay may be minimal or close to zero, and control device 325 may not include a Smith predictor, for example, model simulation 505 that would produce a predicted state vector 506 without delay, which would then be subject to time delay 509. Instead, in some embodiments, Figure 3 The control device 325 may include a delay-free model predictive control 503.

[0087] refer to Figure 6 In some embodiments, the control device 325 can control one or both of heating the ribbon of glass-forming material 103 (e.g., to reduce viscosity and reduce thickness) or cooling the ribbon of glass-forming material 103 (e.g., to increase viscosity at a location and increase thickness). For example, in some embodiments, Figure 6 The glass manufacturing apparatus 100 may be similar in some respects to Figure 3 and / or Figure 4 Glass manufacturing equipment 100. For example, Figure 6 The glass manufacturing apparatus 100 may include a thickness sensor 301 that can measure the thickness (e.g., as shown) of the glass forming material ribbon 103 before separating the first ribbon portion 401 from the second ribbon portion. Figure 4 In some embodiments, thickness sensor 301 may generate thickness profile 321 and transmit thickness profile 321 to control device 325 via communication line 327. Control device 325 may receive target thickness profile 331 and, based on a comparison between thickness profile 321 and target thickness profile 331, control device 325 may transmit instructions to adjustment device 601.

[0088] In some embodiments, conditioning apparatus 601 may include one or more structures for heating and / or cooling glass forming material ribbon 103. For example, in some embodiments, conditioning apparatus 601 may include laser apparatus 335. Laser apparatus 335 may include laser generator 337 and beam directing apparatus 339. In some embodiments, laser generator 337 may emit a laser beam that may be directed toward one of locations 303, 305, 307, or 309 of glass forming material ribbon 103, which may reduce viscosity at location 303, 305, 307, or 309. In some embodiments, conditioning apparatus 601 may include cooling apparatus 603. Cooling apparatus 603 may include, for example, a cooling tube having one or more openings formed in a wall of the cooling tube. The cooling tube may be hollow and may receive a cooling fluid, such as air. The cooling fluid may flow through the one or more openings in the wall of the cooling tube and may be directed toward glass forming material ribbon 103. In some embodiments, cooling device 603 can increase viscosity and increase thickness at one of locations 303 , 305 , 307 , or 309 of glass forming material ribbon 103 by directing cooling fluid toward one of locations 303 , 305 , 307 , or 309 .

[0089] In some embodiments, a method of manufacturing a glass ribbon may include identifying a first location 303 of a plurality of locations, wherein a first corresponding thickness at the first location 303 exceeds a target thickness. For example, the first corresponding thickness at the first location 303 may be measured by the thickness sensor 301, and the control device 325 may compare the first corresponding thickness to a target thickness from the target thickness profile 331. If the first corresponding thickness exceeds the target thickness, in some embodiments, the method may include directing a laser beam 351 and / or 361 toward the glass-forming material ribbon 103 to reduce viscosity at the first location 303 and to achieve the target thickness at the first location 303. In some embodiments, directing the laser beam 351 and / or 361 may include directing the laser beam 351 and / or 361 toward one or more of the first glass-forming material stream 241 flowing over the first weir 203, the second glass-forming material stream 243 flowing over the second weir 204, or the molten ribbon 245. In some embodiments, a method of manufacturing a glass ribbon may include identifying a second location 305 of a plurality of locations, wherein a second corresponding thickness at the second location 305 is less than the target thickness. For example, the second corresponding thickness at the second location 305 can be measured by the thickness sensor 301, and the control device 325 can compare the second corresponding thickness to the target thickness from the target thickness profile 331. If the second corresponding thickness is less than the target thickness, then in some embodiments, the cooling fluid 605, 607, 609, 611, 621, 623, 625, and / or 627 can be directed toward the ribbon of glass-forming material 103 to increase the viscosity at the particular location and achieve the target thickness at this location. The cooling fluid 605, 607, 609, 611, 621, 623, 625, and / or 627 can be directed toward the same location of the ribbon of glass-forming material 103 as the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367. For example, in some embodiments, cooling fluids 605, 607, 609, and / or 611 can be directed toward molten ribbon 245, while in some embodiments, cooling fluids 621, 623, 625, and / or 627 can be directed toward one or both of first glass forming material flow 241 flowing over first weir 203 or second glass forming material flow 243 flowing over second weir 204.

[0090] In some embodiments, if the second location 305 is identified as including a second corresponding thickness that is less than the target thickness, the method of manufacturing a glass ribbon may include directing cooling fluid 607 and / or 623 toward the ribbon of glass-forming material 103 to increase the viscosity at the second location 305 and achieve the target thickness at the second location 305. For example, directing cooling fluid 607 may include directing cooling fluid 607 and / or 623 toward one or more of first glass-forming material stream 241 flowing through first weir 203, second glass-forming material stream 243 flowing through second weir 204, or molten ribbon 245. For example, cooling fluid 623 may be directed toward one or more of first glass-forming material stream 241 flowing through first weir 203 or second glass-forming material stream 243 flowing through second weir 204, while cooling fluid 607 may be directed toward second location 305 of molten ribbon 245. In this way, control device 325 may cause a change in the thickness of ribbon of glass-forming material 103 depending on whether the thickness at a particular location is greater than or less than the target thickness. For example, when the measured thickness exceeds the target thickness at a specific location, the control device 325 may cause the laser beams 351, 353, 355, 357, 361, 363, 365, and / or 367 to impinge on the ribbon of glass-forming material 103 and reduce the viscosity, thereby reducing the thickness and achieving the target thickness at this location. When the measured thickness at a specific location is less than the target thickness, the control device 325 may cause the cooling fluid 605, 607, 609, 611, 621, 623, 625, and / or 627 to impinge on the ribbon of glass-forming material 103 and increase the viscosity, thereby increasing the thickness and achieving the target thickness at this location.

[0091] refer to Figure 7 In some embodiments, based on the detected thickness of the first ribbon portion 401 that has been separated from the second ribbon portion 403, the control device 325 can control one or both of heating the ribbon of glass-forming material 103 (e.g., to reduce viscosity and reduce thickness) or cooling the ribbon of glass-forming material 103 (e.g., to increase viscosity at a location and increase thickness). For example, in some embodiments, Figure 7 The glass manufacturing apparatus 100 in some aspects may be similar to Figure 3 , Figure 4 and Figure 6 Glass manufacturing equipment 100. For example, Figure 7The glass manufacturing apparatus 100 may include a thickness sensor 301 that can measure the thickness of the first ribbon portion 401 after separating the first ribbon portion 401 from the second ribbon portion 403. In some embodiments, the thickness sensor 301 can generate a thickness profile 321 and transmit the thickness profile 321 to a control device 325 via a communication line 327. The control device 325 can receive a target thickness profile 331, and based on a comparison between the thickness profile 321 and the target thickness profile 331, the control device 325 can transmit instructions to an adjustment device 601, which can include a laser device 335 and a cooling device 603.

[0092] In some embodiments, a method of manufacturing a glass ribbon may include generating a predicted thickness profile of a glass forming material ribbon 103, which includes predicted thicknesses at a plurality of locations 303, 305, 307, and / or 309. For example, in some embodiments, the predicted thickness profile may include Figure 5 . Model predictive control 503 can predict future behavior of the program, for example, a predicted thickness profile of the ribbon of glass forming material 103 at multiple locations 303, 305, 307, or 309 at some time in the future. In some embodiments, identifying a first location (e.g., where the corresponding thickness at the first location exceeds the target thickness) can include comparing the predicted thickness profile to the thickness detected at multiple locations 411, 413, 415, or 417. For example, referring to Figure 5 A comparison 511 can be made between a predicted state vector 510 obtained from the model predictive control 503 and a measured state vector 508, which can include thicknesses detected by the thickness sensor 301 at a plurality of locations 411, 413, 415, or 417. Based on this comparison, if there is a difference, the difference can be represented by a filtered delayed state prediction error 521. In some embodiments, a method of manufacturing a glass ribbon can include generating a second thickness profile for a second ribbon portion 403 based on a comparison between the predicted thickness profile and the thicknesses detected at the plurality of locations 411, 413, 415, or 417. For example, as Figure 5 As shown, the filtered delayed state prediction error 521 can be added to the undelayed predicted state vector 506 to produce a corrected state vector 527. The corrected state vector 527 can be transmitted to the model predictive control 503, and the model predictive control 503 can then be updated according to the corrected state vector 527 to produce a second thickness profile. In some embodiments, the second thickness profile can include an updated thickness profile (e.g., after the initial predicted thickness profile), and the control device 325 can transmit a control instruction to the adjustment device 601 according to the second thickness profile.

[0093] In some embodiments, the control instructions that can be transmitted by the control device 325 to the conditioning apparatus 601 can include instructions to heat and / or cool the second ribbon portion 403. For example, in some embodiments, the method of manufacturing a glass ribbon can include identifying a third location 415 of the plurality of locations 411, 413, 415, or 417, wherein a third corresponding thickness at the third location is less than a target thickness. In some embodiments, the method of manufacturing a glass ribbon can include directing a cooling fluid (e.g., the third cooling fluid 615 and / or 625) toward a fourth location 309 of the second ribbon portion 403 corresponding to the third location 415 of the first ribbon portion 401 to increase the viscosity at the fourth location 309 and achieve the target thickness at the fourth location 309.

[0094] By detecting the thickness of the glass forming material ribbon 103 with the thickness sensor 301, a thickness profile can be generated and transmitted to the control device 325. The control device 325 can compare the detected thickness profile with the target thickness profile and / or the predicted thickness profile, and cause heating (e.g., by the laser device 335) and / or cooling (e.g., by the cooling device 603) at a location of the glass forming material ribbon 103 to adjust the thickness at this location. In some embodiments, for example, Figure 3 and Figure 6 As shown in FIG. 1 , control device 325 may include real-time control of thickness due to the close proximity between the location where thickness sensor 301 detects thickness and the location where heating and / or cooling of glass forming material ribbon 103 occurs. Additionally or alternatively, in some embodiments, as Figure 4 and Figure 7 As shown in , the control device 325 can account for the time delay caused by the separation of the first belt portion 401 before the thickness sensor 301 detects the thickness of the first belt portion 401. In some embodiments, as Figure 5 As shown in , the control device 325 can model the effect of the laser device 335 (and / or the cooling device 603) by generating a predicted thickness profile, which can predict the thickness response based on the power of the laser device 335 (and / or the cooling device 603), time delay, thickness changes based on the input location and surrounding locations, etc. In this way, Figure 5 A control scheme can provide more precise control of thickness.

[0095] It should be understood that although the various embodiments have been described in detail with respect to certain illustrative and specific examples thereof, the present application should not be considered limited thereto since various modifications and combinations of the disclosed features are possible without departing from the claims of the present application.

Claims

1. A method for manufacturing a glass ribbon, comprising: moving a ribbon of glass forming material along a travel path in a direction of travel; detecting a thickness of the ribbon of glass-forming material at a plurality of locations on the ribbon of glass-forming material; identifying a location among the plurality of locations, wherein a corresponding thickness at the location exceeds a target thickness; correlating the thickness change rate and the thickness difference between the corresponding thickness and the target thickness with the laser power of the laser beam; generating a predicted thickness profile of the ribbon of glass forming material, the predicted thickness profile including predicted thicknesses at the plurality of locations, and calculating the associated laser power of the laser beam and the location at which the laser beam strikes the ribbon of glass forming material based on the predicted thickness profile; and The laser beam is directed toward the calculated location on the ribbon of glass forming material at the calculated laser power to reduce viscosity at the identified location and achieve the target thickness at the identified location.

2. The method of claim 1, wherein the identifying comprises: A second location among the plurality of locations is identified, wherein a second corresponding thickness at the second location is less than the target thickness.

3. The method of claim 2, further comprising: A cooling fluid is directed toward the ribbon of glass forming material to increase viscosity at the second location and to achieve the target thickness at the second location.

4. The method of claim 1, further comprising: passing a first stream of glass-forming material over a first weir of a forming wedge; flowing a second stream of glass-forming material over a second weir of the forming wedge; The first stream of glass-forming material is fused with the second stream of glass-forming material to form a molten ribbon.

5. The method of claim 4, wherein directing the laser beam comprises: The laser beam is directed toward one or more of the first flow of glass-forming material flowing over the first weir, the second flow of glass-forming material flowing over the second weir, or the molten ribbon.

6. The method of claim 1 wherein said sensing of said thickness of said ribbon of glass forming material occurs at said plurality of locations spaced apart along a first axis generally perpendicular to said direction of travel.

7. A method as described in any one of claims 1 to 6, wherein after separating the first band portion of the glass forming material band from the second band portion, the detecting of the thickness of the glass forming material band occurs in the first band portion of the glass forming material band, the first band portion includes a first position, the first position of the first band portion corresponds to the position of the first position of the second band portion, and the first band portion includes a second position, the second position of the first band portion corresponds to the position of the second position of the second band portion, wherein a thickness sensor detects the thickness of the first position and the second position of the first band portion, and compares the thickness of the first position and the second position with the target thickness.

8. A method for manufacturing a glass ribbon, comprising: moving a ribbon of glass forming material along a travel path in a direction of travel; detecting a thickness of the ribbon of glass-forming material at a plurality of locations on the ribbon of glass-forming material; identifying a first location among the plurality of locations and a second location among the plurality of locations, wherein a first corresponding thickness at the first location exceeds a target thickness, and wherein a second corresponding thickness at the second location is less than the target thickness; generating a predicted thickness profile of the ribbon of glass forming material, the predicted thickness profile including predicted thicknesses at the plurality of locations, and calculating a laser power of a laser beam and a location at which the laser beam strikes the ribbon of glass forming material based on the predicted thickness profile; directing the laser beam at the calculated laser power toward a calculated location on the ribbon of glass forming material to reduce viscosity at the first location and achieve the target thickness at the first location; and A cooling fluid is directed toward the ribbon of glass forming material to increase viscosity at the second location and to achieve the target thickness at the second location.

9. The method of claim 8, further comprising: passing a first stream of glass-forming material over a first weir of a forming wedge; flowing a second stream of glass-forming material over a second weir of the forming wedge; and The first stream of glass-forming material is fused with the second stream of glass-forming material to form a molten ribbon.

10. The method of claim 9, wherein directing the laser beam comprises: The laser beam is directed toward one or more of the first flow of glass-forming material flowing over the first weir, the second flow of glass-forming material flowing over the second weir, or the molten ribbon.

11. The method of claim 9, wherein directing the cooling fluid comprises: The cooling fluid is directed toward one or more of the first flow of glass-forming material flowing over the first weir, the second flow of glass-forming material flowing over the second weir, or the molten ribbon.

12. The method of any one of claims 8 to 11, wherein the detecting of the thickness of the glass forming material strip occurs in the first strip portion of the glass forming material strip after the first strip portion of the glass forming material strip is separated from the second strip portion.

13. The method of claim 12, further comprising: calculating a time delay between said separating said first belt portion and said detecting said thickness; and The laser beam and the cooling fluid are directed toward the second belt portion in accordance with the time delay.

14. A method for manufacturing a glass ribbon, comprising: moving a ribbon of glass forming material along a travel path in a direction of travel; separating a first ribbon portion of the ribbon of glass-forming material from a second ribbon portion of the ribbon of glass-forming material; detecting a thickness at a plurality of locations of the first belt portion; identifying a first location among the plurality of locations, wherein a corresponding thickness at the first location exceeds a target thickness; calculating a time delay between separation of the first belt portion and the thickness detection; and generating a predicted thickness profile of the ribbon of glass forming material, the predicted thickness profile including predicted thicknesses at the plurality of locations, and calculating a laser power of a laser beam and a location at which the laser beam strikes the ribbon of glass forming material based on the predicted thickness profile; The laser beam is directed toward a calculated second position of the second tape portion corresponding to the first position of the first tape portion at the calculated laser power in accordance with the time delay to reduce viscosity at the second position and achieve the target thickness at the second position.

15. The method of claim 14, wherein: The time delay between said separating said first tape portion and said detecting said thickness results in a time delay between when said laser beam strikes said second tape portion and when a change in thickness of said second tape portion is detected.

16. The method of claim 15, wherein said identifying said first location comprises comparing said predicted thickness profile to said thicknesses detected at said plurality of locations.

17. The method of claim 16, further comprising: A second thickness profile of the second belt portion is generated based on the comparison between the predicted thickness profile and the thicknesses detected at the plurality of locations.

18. The method of any one of claims 14 to 17, further comprising: A third location of the plurality of locations is identified, wherein a third corresponding thickness at the third location is less than the target thickness.

19. The method of claim 18, further comprising: Cooling fluid is directed toward a fourth position of the second tape portion corresponding to the third position of the first tape portion to increase viscosity at the fourth position and to achieve the target thickness at the fourth position.

20. A method of manufacturing a glass ribbon, comprising: moving a ribbon of glass forming material along a travel path in a direction of travel; detecting a thickness of the ribbon of glass-forming material at a plurality of locations on the ribbon of glass-forming material; Identify one or more of the following: a location among the plurality of locations, wherein a corresponding thickness at the location exceeds a target thickness; or a second location among the plurality of locations, wherein a second corresponding thickness at the second location is less than the target thickness; When the corresponding thickness at the identified position exceeds the target thickness, correlating the thickness change rate and the thickness difference between the corresponding thickness and the target thickness with the laser power of the laser beam; generating a predicted thickness profile of the ribbon of glass forming material, the predicted thickness profile including predicted thicknesses at the plurality of locations, and calculating the associated laser power of the laser beam and the location at which the laser beam strikes the ribbon of glass forming material based on the predicted thickness profile; and Do one or more of the following: directing the laser beam toward the calculated location on the ribbon of glass forming material at the calculated laser power to reduce viscosity at the identified location and achieve the target thickness at the identified location; or A cooling fluid is directed toward the ribbon of glass forming material to increase viscosity at the identified second location and to achieve the target thickness at the identified second location.

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